1: /*
2: * OSPF AS external route calculation.
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: #include <zebra.h>
24:
25: #include "thread.h"
26: #include "memory.h"
27: #include "hash.h"
28: #include "linklist.h"
29: #include "prefix.h"
30: #include "if.h"
31: #include "table.h"
32: #include "vty.h"
33: #include "log.h"
34:
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"
48:
49: struct ospf_route *
50: ospf_find_asbr_route (struct ospf *ospf,
51: struct route_table *rtrs, struct prefix_ipv4 *asbr)
52: {
53: struct route_node *rn;
54: struct ospf_route *or, *best = NULL;
55: struct listnode *node;
56: struct list *chosen;
57:
58: /* Sanity check. */
59: if (rtrs == NULL)
60: return NULL;
61:
62: rn = route_node_lookup (rtrs, (struct prefix *) asbr);
63: if (! rn)
64: return NULL;
65:
66: route_unlock_node (rn);
67:
68: chosen = list_new ();
69:
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);
77:
78: /* If none is found -- look through all. */
79: if (listcount (chosen) == 0)
80: {
81: list_free (chosen);
82: chosen = rn->info;
83: }
84:
85: /* Now find the route with least cost. */
86: for (ALL_LIST_ELEMENTS_RO (chosen, node, or))
87: if (or->cost < OSPF_LS_INFINITY)
88: {
89: if (best == NULL)
90: best = or;
91: else if (best->cost > or->cost)
92: best = or;
93: else if (best->cost == or->cost &&
94: IPV4_ADDR_CMP (&best->u.std.area_id,
95: &or->u.std.area_id) < 0)
96: best = or;
97: }
98:
99: if (chosen != rn->info)
100: list_delete (chosen);
101:
102: return best;
103: }
104:
105: struct ospf_route *
106: ospf_find_asbr_route_through_area (struct route_table *rtrs,
107: struct prefix_ipv4 *asbr,
108: struct ospf_area *area)
109: {
110: struct route_node *rn;
111:
112: /* Sanity check. */
113: if (rtrs == NULL)
114: return NULL;
115:
116: rn = route_node_lookup (rtrs, (struct prefix *) asbr);
117:
118: if (rn)
119: {
120: struct listnode *node;
121: struct ospf_route *or;
122:
123: route_unlock_node (rn);
124:
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))
127: return or;
128: }
129:
130: return NULL;
131: }
132:
133: static void
134: ospf_ase_complete_direct_routes (struct ospf_route *ro, struct in_addr nexthop)
135: {
136: struct listnode *node;
137: struct ospf_path *op;
138:
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;
142: }
143:
144: static int
145: ospf_ase_forward_address_check (struct ospf *ospf, struct in_addr fwd_addr)
146: {
147: struct listnode *ifn;
148: struct ospf_interface *oi;
149:
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))
154: return 0;
155:
156: return 1;
157: }
158:
159: #if 0
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)
166: {
167: struct prefix_ipv4 asbr;
168: struct ospf_route *asbr_route;
169: struct route_node *rn;
170:
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);
176:
177: asbr_route = ospf_find_asbr_route (ospf, rt_router, &asbr);
178:
179: if (asbr_route == NULL)
180: {
181: if (IS_DEBUG_OSPF (lsa, LSA))
182: zlog_debug ("ospf_ase_calculate(): Route to ASBR %s not found",
183: inet_ntoa (asbr.prefix));
184: return NULL;
185: }
186:
187: if (!(asbr_route->u.std.flags & ROUTER_LSA_EXTERNAL))
188: {
189: if (IS_DEBUG_OSPF (lsa, LSA))
190: zlog_debug ("ospf_ase_calculate(): Originating router is not an ASBR");
191: return NULL;
192: }
193:
194: if (al->e[0].fwd_addr.s_addr != 0)
195: {
196: if (IS_DEBUG_OSPF (lsa, LSA))
197: zlog_debug ("ospf_ase_calculate(): "
198: "Forwarding address is not 0.0.0.0.");
199:
200: if (! ospf_ase_forward_address_check (ospf, al->e[0].fwd_addr))
201: {
202: if (IS_DEBUG_OSPF (lsa, LSA))
203: zlog_debug ("ospf_ase_calculate(): "
204: "Forwarding address is one of our addresses, Ignore.");
205: return NULL;
206: }
207:
208: if (IS_DEBUG_OSPF (lsa, LSA))
209: zlog_debug ("ospf_ase_calculate(): "
210: "Looking up in the Network Routing Table.");
211:
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;
216:
217: rn = route_node_match (rt_network, (struct prefix *) &asbr);
218:
219: if (rn == NULL)
220: {
221: if (IS_DEBUG_OSPF (lsa, LSA))
222: zlog_debug ("ospf_ase_calculate(): "
223: "Couldn't find a route to the forwarding address.");
224: return NULL;
225: }
226:
227: route_unlock_node (rn);
228:
229: if ((asbr_route = rn->info) == NULL)
230: {
231: if (IS_DEBUG_OSPF (lsa, LSA))
232: zlog_debug ("ospf_ase_calculate(): "
233: "Somehow OSPF route to ASBR is lost");
234: return NULL;
235: }
236: }
237:
238: return asbr_route;
239: }
240: #endif
241:
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)
245: {
246: struct as_external_lsa *al;
247: struct ospf_route *new;
248:
249: al = (struct as_external_lsa *) lsa->data;
250:
251: new = ospf_route_new ();
252:
253: /* Set redistributed type -- does make sense? */
254: /* new->type = type; */
255: new->id = al->header.id;
256: new->mask = al->mask;
257:
258: if (!IS_EXTERNAL_METRIC (al->e[0].tos))
259: {
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 */
264: }
265: else
266: {
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 */
272: }
273:
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;
278:
279: assert (new != asbr_route);
280:
281: return new;
282: }
283:
284: #define OSPF_ASE_CALC_INTERVAL 1
285:
286: int
287: ospf_ase_calculate_route (struct ospf *ospf, struct ospf_lsa * lsa)
288: {
289: u_int32_t metric;
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;
295: int ret;
296:
297: assert (lsa);
298: al = (struct as_external_lsa *) lsa->data;
299:
300: if (lsa->data->type == OSPF_AS_NSSA_LSA)
301: if (IS_DEBUG_OSPF_NSSA)
302: zlog_debug ("ospf_ase_calc(): Processing Type-7");
303:
304: /* Stay away from any Local Translated Type-7 LSAs */
305: if (CHECK_FLAG (lsa->flags, OSPF_LSA_LOCAL_XLT))
306: {
307: if (IS_DEBUG_OSPF_NSSA)
308: zlog_debug ("ospf_ase_calc(): Rejecting Local Xlt'd");
309: return 0;
310: }
311:
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)
318: {
319: if (IS_DEBUG_OSPF (lsa, LSA))
320: zlog_debug ("Route[External]: Metric is OSPF_LS_INFINITY");
321: return 0;
322: }
323: if (IS_LSA_MAXAGE (lsa))
324: {
325: if (IS_DEBUG_OSPF (lsa, LSA))
326: zlog_debug ("Route[External]: AS-external-LSA is MAXAGE");
327: return 0;
328: }
329:
330: /* (2) If the LSA was originated by the calculating router itself,
331: examine the next LSA. */
332: if (IS_LSA_SELF (lsa))
333: {
334: if (IS_DEBUG_OSPF (lsa, LSA))
335: zlog_debug ("Route[External]: AS-external-LSA is self originated");
336: return 0;
337: }
338:
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
346: in the list. */
347:
348: asbr.family = AF_INET;
349: asbr.prefix = al->header.adv_router;
350: asbr.prefixlen = IPV4_MAX_BITLEN;
351: apply_mask_ipv4 (&asbr);
352:
353: asbr_route = ospf_find_asbr_route (ospf, ospf->new_rtrs, &asbr);
354: if (asbr_route == NULL)
355: {
356: if (IS_DEBUG_OSPF (lsa, LSA))
357: zlog_debug ("Route[External]: Can't find originating ASBR route");
358: return 0;
359: }
360: if (!(asbr_route->u.std.flags & ROUTER_LSA_EXTERNAL))
361: {
362: if (IS_DEBUG_OSPF (lsa, LSA))
363: zlog_debug ("Route[External]: Originating router is not an ASBR");
364: return 0;
365: }
366:
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. */
371:
372: if (al->e[0].fwd_addr.s_addr == 0)
373: {
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
384: chosen. */
385:
386: /* asbr_route already contains the requested route */
387: }
388: else
389: {
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))
396: {
397: if (IS_DEBUG_OSPF (lsa, LSA))
398: zlog_debug ("Route[External]: Forwarding address is our router "
399: "address");
400: return 0;
401: }
402:
403: asbr.family = AF_INET;
404: asbr.prefix = al->e[0].fwd_addr;
405: asbr.prefixlen = IPV4_MAX_BITLEN;
406:
407: rn = route_node_match (ospf->new_table, (struct prefix *) &asbr);
408:
409: if (rn == NULL || (asbr_route = rn->info) == NULL)
410: {
411: if (IS_DEBUG_OSPF (lsa, LSA))
412: zlog_debug ("Route[External]: Can't find route to forwarding "
413: "address");
414: if (rn)
415: route_unlock_node (rn);
416: return 0;
417: }
418:
419: route_unlock_node (rn);
420: }
421:
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. */
426:
427:
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);
438:
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
444: paths. */
445:
446: /* Set prefix. */
447: p.family = AF_INET;
448: p.prefix = al->header.id;
449: p.prefixlen = ip_masklen (al->mask);
450:
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)))
455: {
456: route_unlock_node(rn);
457: if (rn->info == NULL)
458: zlog_info ("Route[External]: rn->info NULL");
459: if (new)
460: ospf_route_free (new);
461: return 0;
462: }
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);
468:
469: if (!rn || (or = rn->info) == NULL)
470: {
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);
474:
475: ospf_route_add (ospf->new_external_route, &p, new, asbr_route);
476:
477: if (al->e[0].fwd_addr.s_addr)
478: ospf_ase_complete_direct_routes (new, al->e[0].fwd_addr);
479: return 0;
480: }
481: else
482: {
483: /* (a) Intra-area and inter-area paths are always preferred
484: over AS external paths.
485:
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);
491:
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
497: 16.4.1.
498:
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
507: addresses.
508: */
509: /* New route is better */
510: if (ret < 0)
511: {
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);
517: or = new;
518: new = NULL;
519: }
520: /* Old route is better */
521: else if (ret > 0)
522: {
523: if (IS_DEBUG_OSPF (lsa, LSA))
524: zlog_debug ("Route[External]: Old route is better");
525: /* do nothing */
526: }
527: /* Routes are equal */
528: else
529: {
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);
535: }
536: }
537: /* Make sure setting newly calculated ASBR route.*/
538: or->u.ext.asbr = asbr_route;
539: if (new)
540: ospf_route_free (new);
541:
542: lsa->route = or;
543: return 0;
544: }
545:
546: static int
547: ospf_ase_route_match_same (struct route_table *rt, struct prefix *prefix,
548: struct ospf_route *newor)
549: {
550: struct route_node *rn;
551: struct ospf_route *or;
552: struct ospf_path *op;
553: struct ospf_path *newop;
554: struct listnode *n1;
555: struct listnode *n2;
556:
557: if (! rt || ! prefix)
558: return 0;
559:
560: rn = route_node_lookup (rt, prefix);
561: if (! rn)
562: return 0;
563:
564: route_unlock_node (rn);
565:
566: or = rn->info;
567: if (or->path_type != newor->path_type)
568: return 0;
569:
570: switch (or->path_type)
571: {
572: case OSPF_PATH_TYPE1_EXTERNAL:
573: if (or->cost != newor->cost)
574: return 0;
575: break;
576: case OSPF_PATH_TYPE2_EXTERNAL:
577: if ((or->cost != newor->cost) ||
578: (or->u.ext.type2_cost != newor->u.ext.type2_cost))
579: return 0;
580: break;
581: default:
582: assert (0);
583: return 0;
584: }
585:
586: if (or->paths->count != newor->paths->count)
587: return 0;
588:
589: /* Check each path. */
590: for (n1 = listhead (or->paths), n2 = listhead (newor->paths);
591: n1 && n2; n1 = listnextnode (n1), n2 = listnextnode (n2))
592: {
593: op = listgetdata (n1);
594: newop = listgetdata (n2);
595:
596: if (! IPV4_ADDR_SAME (&op->nexthop, &newop->nexthop))
597: return 0;
598: if (op->ifindex != newop->ifindex)
599: return 0;
600: }
601: return 1;
602: }
603:
604: static int
605: ospf_ase_compare_tables (struct route_table *new_external_route,
606: struct route_table *old_external_route)
607: {
608: struct route_node *rn, *new_rn;
609: struct ospf_route *or;
610:
611: /* Remove deleted routes */
612: for (rn = route_top (old_external_route); rn; rn = route_next (rn))
613: if ((or = rn->info))
614: {
615: if (! (new_rn = route_node_lookup (new_external_route, &rn->p)))
616: ospf_zebra_delete ((struct prefix_ipv4 *) &rn->p, or);
617: else
618: route_unlock_node (new_rn);
619: }
620:
621:
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);
627:
628: return 0;
629: }
630:
631: static int
632: ospf_ase_calculate_timer (struct thread *t)
633: {
634: struct ospf *ospf;
635: struct ospf_lsa *lsa;
636: struct route_node *rn;
637: struct listnode *node;
638: struct ospf_area *area;
639:
640: ospf = THREAD_ARG (t);
641: ospf->t_ase_calc = NULL;
642:
643: if (ospf->ase_calc)
644: {
645: ospf->ase_calc = 0;
646:
647: /* Calculate external route for each AS-external-LSA */
648: LSDB_LOOP (EXTERNAL_LSDB (ospf), rn, lsa)
649: ospf_ase_calculate_route (ospf, lsa);
650:
651: /* This version simple adds to the table all NSSA areas */
652: if (ospf->anyNSSA)
653: for (ALL_LIST_ELEMENTS_RO (ospf->areas, node, area))
654: {
655: if (IS_DEBUG_OSPF_NSSA)
656: zlog_debug ("ospf_ase_calculate_timer(): looking at area %s",
657: inet_ntoa (area->area_id));
658:
659: if (area->external_routing == OSPF_AREA_NSSA)
660: LSDB_LOOP (NSSA_LSDB (area), rn, lsa)
661: ospf_ase_calculate_route (ospf, lsa);
662: }
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);
666:
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);
671:
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 ();
676: }
677: return 0;
678: }
679:
680: void
681: ospf_ase_calculate_schedule (struct ospf *ospf)
682: {
683: if (ospf == NULL)
684: return;
685:
686: ospf->ase_calc = 1;
687: }
688:
689: void
690: ospf_ase_calculate_timer_add (struct ospf *ospf)
691: {
692: if (ospf == NULL)
693: return;
694:
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);
698: }
699:
700: void
701: ospf_ase_register_external_lsa (struct ospf_lsa *lsa, struct ospf *top)
702: {
703: struct route_node *rn;
704: struct prefix_ipv4 p;
705: struct list *lst;
706: struct as_external_lsa *al;
707:
708: al = (struct as_external_lsa *) lsa->data;
709: p.family = AF_INET;
710: p.prefix = lsa->data->id;
711: p.prefixlen = ip_masklen (al->mask);
712: apply_mask_ipv4 (&p);
713:
714: rn = route_node_get (top->external_lsas, (struct prefix *) &p);
715: if ((lst = rn->info) == NULL)
716: rn->info = lst = list_new();
717:
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 */
721: }
722:
723: void
724: ospf_ase_unregister_external_lsa (struct ospf_lsa *lsa, struct ospf *top)
725: {
726: struct route_node *rn;
727: struct prefix_ipv4 p;
728: struct list *lst;
729: struct as_external_lsa *al;
730:
731: al = (struct as_external_lsa *) lsa->data;
732: p.family = AF_INET;
733: p.prefix = lsa->data->id;
734: p.prefixlen = ip_masklen (al->mask);
735: apply_mask_ipv4 (&p);
736:
737: rn = route_node_get (top->external_lsas, (struct prefix *) &p);
738: lst = rn->info;
739:
740: /* XXX lst can be NULL */
741: if (lst) {
742: listnode_delete (lst, lsa);
743: ospf_lsa_unlock (&lsa); /* external_lsas list */
744: }
745: }
746:
747: void
748: ospf_ase_external_lsas_finish (struct route_table *rt)
749: {
750: struct route_node *rn;
751: struct ospf_lsa *lsa;
752: struct list *lst;
753: struct listnode *node, *nnode;
754:
755: for (rn = route_top (rt); rn; rn = route_next (rn))
756: if ((lst = rn->info) != NULL)
757: {
758: for (ALL_LIST_ELEMENTS (lst, node, nnode, lsa))
759: ospf_lsa_unlock (&lsa); /* external_lsas lst */
760: list_delete (lst);
761: }
762:
763: route_table_finish (rt);
764: }
765:
766: void
767: ospf_ase_incremental_update (struct ospf *ospf, struct ospf_lsa *lsa)
768: {
769: struct list *lsas;
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;
775:
776: al = (struct as_external_lsa *) lsa->data;
777: p.family = AF_INET;
778: p.prefix = lsa->data->id;
779: p.prefixlen = ip_masklen (al->mask);
780: apply_mask_ipv4 (&p);
781:
782: /* if new_table is NULL, there was no spf calculation, thus
783: incremental update is unneeded */
784: if (!ospf->new_table)
785: return;
786:
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). */
790:
791: rn = route_node_lookup (ospf->new_table, (struct prefix *) &p);
792: if (rn)
793: {
794: route_unlock_node (rn);
795: if (rn->info)
796: return;
797: }
798:
799: rn = route_node_lookup (ospf->external_lsas, (struct prefix *) &p);
800: assert (rn);
801: assert (rn->info);
802: lsas = rn->info;
803: route_unlock_node (rn);
804:
805: for (ALL_LIST_ELEMENTS_RO (lsas, node, lsa))
806: ospf_ase_calculate_route (ospf, lsa);
807:
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);
811: if (rn && rn->info)
812: {
813: rn2 = route_node_get (tmp_old, (struct prefix *) &p);
814: rn2->info = rn->info;
815: }
816:
817: /* install changes to zebra */
818: ospf_ase_compare_tables (ospf->new_external_route, tmp_old);
819:
820: /* update ospf->old_external_route table */
821: if (rn && rn->info)
822: ospf_route_free ((struct ospf_route *) rn->info);
823:
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)
827: {
828: if (!rn)
829: rn = route_node_get (ospf->old_external_route, (struct prefix *) &p);
830: rn->info = rn2->info;
831: }
832: else
833: {
834: /* remove route node from ospf->old_external_route */
835: if (rn)
836: {
837: rn->info = NULL;
838: route_unlock_node (rn);
839: route_unlock_node (rn);
840: }
841: }
842:
843: if (rn2)
844: {
845: /* rn2->info is stored in route node of ospf->old_external_route */
846: rn2->info = NULL;
847: route_unlock_node (rn2);
848: route_unlock_node (rn2);
849: }
850:
851: route_table_finish (tmp_old);
852: }
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