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718e3744 | 1 | /* OSPF SPF calculation. |
2 | Copyright (C) 1999, 2000 Kunihiro Ishiguro, Toshiaki Takada | |
3 | ||
4 | This file is part of GNU Zebra. | |
5 | ||
6 | GNU Zebra is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU General Public License as published by the | |
8 | Free Software Foundation; either version 2, or (at your option) any | |
9 | later version. | |
10 | ||
11 | GNU Zebra is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU Zebra; see the file COPYING. If not, write to the Free | |
18 | Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
19 | 02111-1307, USA. */ | |
20 | ||
21 | #include <zebra.h> | |
22 | ||
23 | #include "thread.h" | |
24 | #include "memory.h" | |
25 | #include "hash.h" | |
26 | #include "linklist.h" | |
27 | #include "prefix.h" | |
28 | #include "if.h" | |
29 | #include "table.h" | |
30 | #include "log.h" | |
31 | #include "sockunion.h" /* for inet_ntop () */ | |
32 | ||
33 | #include "ospfd/ospfd.h" | |
34 | #include "ospfd/ospf_interface.h" | |
35 | #include "ospfd/ospf_ism.h" | |
36 | #include "ospfd/ospf_asbr.h" | |
37 | #include "ospfd/ospf_lsa.h" | |
38 | #include "ospfd/ospf_lsdb.h" | |
39 | #include "ospfd/ospf_neighbor.h" | |
40 | #include "ospfd/ospf_nsm.h" | |
41 | #include "ospfd/ospf_spf.h" | |
42 | #include "ospfd/ospf_route.h" | |
43 | #include "ospfd/ospf_ia.h" | |
44 | #include "ospfd/ospf_ase.h" | |
45 | #include "ospfd/ospf_abr.h" | |
46 | #include "ospfd/ospf_dump.h" | |
47 | ||
48 | #define DEBUG | |
49 | ||
50 | struct vertex_nexthop * | |
51 | vertex_nexthop_new (struct vertex *parent) | |
52 | { | |
53 | struct vertex_nexthop *new; | |
54 | ||
55 | new = XCALLOC (MTYPE_OSPF_NEXTHOP, sizeof (struct vertex_nexthop)); | |
56 | new->parent = parent; | |
57 | ||
58 | return new; | |
59 | } | |
60 | ||
61 | void | |
62 | vertex_nexthop_free (struct vertex_nexthop *nh) | |
63 | { | |
64 | XFREE (MTYPE_OSPF_NEXTHOP, nh); | |
65 | } | |
66 | ||
67 | struct vertex_nexthop * | |
68 | vertex_nexthop_dup (struct vertex_nexthop *nh) | |
69 | { | |
70 | struct vertex_nexthop *new; | |
71 | ||
72 | new = vertex_nexthop_new (nh->parent); | |
73 | ||
74 | new->oi = nh->oi; | |
75 | new->router = nh->router; | |
76 | ||
77 | return new; | |
78 | } | |
718e3744 | 79 | \f |
0c0f9cd5 | 80 | |
718e3744 | 81 | struct vertex * |
82 | ospf_vertex_new (struct ospf_lsa *lsa) | |
83 | { | |
84 | struct vertex *new; | |
85 | ||
86 | new = XMALLOC (MTYPE_OSPF_VERTEX, sizeof (struct vertex)); | |
87 | memset (new, 0, sizeof (struct vertex)); | |
88 | ||
89 | new->flags = 0; | |
90 | new->type = lsa->data->type; | |
91 | new->id = lsa->data->id; | |
92 | new->lsa = lsa->data; | |
93 | new->distance = 0; | |
94 | new->child = list_new (); | |
95 | new->nexthop = list_new (); | |
d355bfa7 | 96 | new->backlink = -1; |
718e3744 | 97 | |
98 | return new; | |
99 | } | |
100 | ||
101 | void | |
102 | ospf_vertex_free (struct vertex *v) | |
103 | { | |
52dc7ee6 | 104 | struct listnode *node; |
718e3744 | 105 | |
106 | list_delete (v->child); | |
107 | ||
108 | if (listcount (v->nexthop) > 0) | |
109 | for (node = listhead (v->nexthop); node; nextnode (node)) | |
110 | vertex_nexthop_free (node->data); | |
111 | ||
112 | list_delete (v->nexthop); | |
113 | ||
114 | XFREE (MTYPE_OSPF_VERTEX, v); | |
115 | } | |
116 | ||
630e4807 | 117 | void |
eb1ce605 | 118 | ospf_vertex_dump(const char *msg, struct vertex *v, |
630e4807 | 119 | int print_nexthops, int print_children) |
120 | { | |
121 | if ( ! IS_DEBUG_OSPF_EVENT) | |
122 | return; | |
123 | ||
124 | zlog_info("%s %s vertex %s distance %u backlink %d flags %u", | |
125 | msg, | |
126 | v->type == OSPF_VERTEX_ROUTER ? "Router" : "Network", | |
127 | inet_ntoa(v->lsa->id), | |
128 | v->distance, | |
129 | v->backlink, | |
130 | (unsigned int)v->flags); | |
131 | ||
132 | if (print_nexthops) | |
133 | { | |
52dc7ee6 | 134 | struct listnode *nnode; |
630e4807 | 135 | for (nnode = listhead (v->nexthop); nnode; nextnode (nnode)) |
136 | { | |
137 | char buf1[BUFSIZ]; | |
138 | char buf2[BUFSIZ]; | |
139 | struct vertex_nexthop *nexthop; | |
140 | ||
141 | nexthop = getdata (nnode); | |
142 | if (nexthop) | |
143 | { | |
144 | zlog_info (" nexthop %s interface %s parent %s", | |
145 | inet_ntop(AF_INET, &nexthop->router, buf1, BUFSIZ), | |
146 | nexthop->oi ? IF_NAME(nexthop->oi) : "NULL", | |
147 | nexthop->parent ? inet_ntop(AF_INET, | |
148 | &nexthop->parent->id, | |
149 | buf2, BUFSIZ) | |
150 | : "NULL"); | |
151 | } | |
152 | } | |
153 | } | |
154 | ||
155 | if (print_children) | |
156 | { | |
52dc7ee6 | 157 | struct listnode *cnode; |
630e4807 | 158 | for (cnode = listhead (v->child); cnode; nextnode (cnode)) |
159 | { | |
160 | struct vertex *cv = getdata (cnode); | |
161 | if (cv) | |
162 | ospf_vertex_dump(" child:", cv, 0, 0); | |
163 | } | |
164 | } | |
165 | } | |
166 | ||
167 | ||
168 | /* Add a vertex to the list of children in each of its parents. */ | |
718e3744 | 169 | void |
170 | ospf_vertex_add_parent (struct vertex *v) | |
171 | { | |
172 | struct vertex_nexthop *nh; | |
52dc7ee6 | 173 | struct listnode *node; |
718e3744 | 174 | |
175 | for (node = listhead (v->nexthop); node; nextnode (node)) | |
176 | { | |
177 | nh = (struct vertex_nexthop *) getdata (node); | |
178 | ||
179 | /* No need to add two links from the same parent. */ | |
180 | if (listnode_lookup (nh->parent->child, v) == NULL) | |
0c0f9cd5 | 181 | listnode_add (nh->parent->child, v); |
718e3744 | 182 | } |
183 | } | |
184 | \f | |
185 | void | |
186 | ospf_spf_init (struct ospf_area *area) | |
187 | { | |
188 | struct vertex *v; | |
189 | ||
190 | /* Create root node. */ | |
191 | v = ospf_vertex_new (area->router_lsa_self); | |
192 | ||
193 | area->spf = v; | |
194 | ||
195 | /* Reset ABR and ASBR router counts. */ | |
196 | area->abr_count = 0; | |
197 | area->asbr_count = 0; | |
198 | } | |
199 | ||
630e4807 | 200 | /* Check if the vertex represented by lsa is on the SPF tree. */ |
718e3744 | 201 | int |
202 | ospf_spf_has_vertex (struct route_table *rv, struct route_table *nv, | |
203 | struct lsa_header *lsa) | |
204 | { | |
205 | struct prefix p; | |
206 | struct route_node *rn; | |
207 | ||
208 | p.family = AF_INET; | |
209 | p.prefixlen = IPV4_MAX_BITLEN; | |
210 | p.u.prefix4 = lsa->id; | |
211 | ||
212 | if (lsa->type == OSPF_ROUTER_LSA) | |
213 | rn = route_node_get (rv, &p); | |
214 | else | |
215 | rn = route_node_get (nv, &p); | |
216 | ||
217 | if (rn->info != NULL) | |
218 | { | |
219 | route_unlock_node (rn); | |
220 | return 1; | |
221 | } | |
222 | return 0; | |
223 | } | |
224 | ||
630e4807 | 225 | /* Find the vertex specified by the given id and LSA type |
226 | * in vlist (the candidate list). | |
227 | */ | |
52dc7ee6 | 228 | struct listnode * |
229 | ospf_vertex_lookup (struct list *vlist, struct in_addr id, int type) | |
718e3744 | 230 | { |
52dc7ee6 | 231 | struct listnode *node; |
718e3744 | 232 | struct vertex *v; |
233 | ||
234 | for (node = listhead (vlist); node; nextnode (node)) | |
235 | { | |
236 | v = (struct vertex *) getdata (node); | |
237 | if (IPV4_ADDR_SAME (&id, &v->id) && type == v->type) | |
238 | return node; | |
239 | } | |
240 | ||
241 | return NULL; | |
242 | } | |
243 | ||
d355bfa7 | 244 | /* return index of link back to V from W, or -1 if no link found */ |
718e3744 | 245 | int |
246 | ospf_lsa_has_link (struct lsa_header *w, struct lsa_header *v) | |
247 | { | |
eb1ce605 | 248 | unsigned int i, length; |
718e3744 | 249 | struct router_lsa *rl; |
250 | struct network_lsa *nl; | |
251 | ||
252 | /* In case of W is Network LSA. */ | |
253 | if (w->type == OSPF_NETWORK_LSA) | |
254 | { | |
255 | if (v->type == OSPF_NETWORK_LSA) | |
d355bfa7 | 256 | return -1; |
718e3744 | 257 | |
258 | nl = (struct network_lsa *) w; | |
259 | length = (ntohs (w->length) - OSPF_LSA_HEADER_SIZE - 4) / 4; | |
0c0f9cd5 | 260 | |
718e3744 | 261 | for (i = 0; i < length; i++) |
262 | if (IPV4_ADDR_SAME (&nl->routers[i], &v->id)) | |
d355bfa7 | 263 | return i; |
264 | return -1; | |
718e3744 | 265 | } |
266 | ||
267 | /* In case of W is Router LSA. */ | |
268 | if (w->type == OSPF_ROUTER_LSA) | |
269 | { | |
270 | rl = (struct router_lsa *) w; | |
271 | ||
272 | length = ntohs (w->length); | |
273 | ||
274 | for (i = 0; | |
0c0f9cd5 | 275 | i < ntohs (rl->links) && length >= sizeof (struct router_lsa); |
276 | i++, length -= 12) | |
718e3744 | 277 | { |
278 | switch (rl->link[i].type) | |
279 | { | |
280 | case LSA_LINK_TYPE_POINTOPOINT: | |
281 | case LSA_LINK_TYPE_VIRTUALLINK: | |
282 | /* Router LSA ID. */ | |
283 | if (v->type == OSPF_ROUTER_LSA && | |
284 | IPV4_ADDR_SAME (&rl->link[i].link_id, &v->id)) | |
285 | { | |
d355bfa7 | 286 | return i; |
718e3744 | 287 | } |
288 | break; | |
289 | case LSA_LINK_TYPE_TRANSIT: | |
290 | /* Network LSA ID. */ | |
291 | if (v->type == OSPF_NETWORK_LSA && | |
292 | IPV4_ADDR_SAME (&rl->link[i].link_id, &v->id)) | |
293 | { | |
d355bfa7 | 294 | return i; |
0c0f9cd5 | 295 | } |
718e3744 | 296 | break; |
297 | case LSA_LINK_TYPE_STUB: | |
298 | /* Not take into count? */ | |
299 | continue; | |
300 | default: | |
301 | break; | |
302 | } | |
303 | } | |
304 | } | |
d355bfa7 | 305 | return -1; |
718e3744 | 306 | } |
307 | ||
308 | /* Add the nexthop to the list, only if it is unique. | |
309 | * If it's not unique, free the nexthop entry. | |
310 | */ | |
311 | void | |
52dc7ee6 | 312 | ospf_nexthop_add_unique (struct vertex_nexthop *new, struct list *nexthop) |
718e3744 | 313 | { |
314 | struct vertex_nexthop *nh; | |
52dc7ee6 | 315 | struct listnode *node; |
718e3744 | 316 | int match; |
317 | ||
318 | match = 0; | |
319 | for (node = listhead (nexthop); node; nextnode (node)) | |
320 | { | |
321 | nh = node->data; | |
322 | ||
323 | /* Compare the two entries. */ | |
324 | /* XXX | |
325 | * Comparing the parent preserves the shortest path tree | |
326 | * structure even when the nexthops are identical. | |
327 | */ | |
328 | if (nh->oi == new->oi && | |
0c0f9cd5 | 329 | IPV4_ADDR_SAME (&nh->router, &new->router) && |
330 | nh->parent == new->parent) | |
331 | { | |
332 | match = 1; | |
333 | break; | |
334 | } | |
718e3744 | 335 | } |
336 | ||
337 | if (!match) | |
338 | listnode_add (nexthop, new); | |
339 | else | |
340 | vertex_nexthop_free (new); | |
341 | } | |
342 | ||
343 | /* Merge entries in list b into list a. */ | |
344 | void | |
52dc7ee6 | 345 | ospf_nexthop_merge (struct list *a, struct list *b) |
718e3744 | 346 | { |
347 | struct listnode *n; | |
348 | ||
349 | for (n = listhead (b); n; nextnode (n)) | |
350 | { | |
351 | ospf_nexthop_add_unique (n->data, a); | |
352 | } | |
353 | } | |
354 | ||
355 | #define ROUTER_LSA_MIN_SIZE 12 | |
356 | #define ROUTER_LSA_TOS_SIZE 4 | |
357 | ||
630e4807 | 358 | /* Find the next link after prev_link from v to w. If prev_link is |
359 | * NULL, return the first link from v to w. Ignore stub and virtual links; | |
360 | * these link types will never be returned. | |
361 | */ | |
718e3744 | 362 | struct router_lsa_link * |
363 | ospf_get_next_link (struct vertex *v, struct vertex *w, | |
0c0f9cd5 | 364 | struct router_lsa_link *prev_link) |
718e3744 | 365 | { |
366 | u_char *p; | |
367 | u_char *lim; | |
368 | struct router_lsa_link *l; | |
369 | ||
370 | if (prev_link == NULL) | |
630e4807 | 371 | p = ((u_char *) v->lsa) + OSPF_LSA_HEADER_SIZE + 4; |
718e3744 | 372 | else |
373 | { | |
0c0f9cd5 | 374 | p = (u_char *) prev_link; |
718e3744 | 375 | p += (ROUTER_LSA_MIN_SIZE + |
376 | (prev_link->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); | |
377 | } | |
0c0f9cd5 | 378 | |
718e3744 | 379 | lim = ((u_char *) v->lsa) + ntohs (v->lsa->length); |
380 | ||
381 | while (p < lim) | |
382 | { | |
383 | l = (struct router_lsa_link *) p; | |
384 | ||
0c0f9cd5 | 385 | p += (ROUTER_LSA_MIN_SIZE + (l->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); |
718e3744 | 386 | |
387 | if (l->m[0].type == LSA_LINK_TYPE_STUB) | |
388 | continue; | |
389 | ||
390 | /* Defer NH calculation via VLs until summaries from | |
391 | transit areas area confidered */ | |
392 | ||
393 | if (l->m[0].type == LSA_LINK_TYPE_VIRTUALLINK) | |
0c0f9cd5 | 394 | continue; |
718e3744 | 395 | |
396 | if (IPV4_ADDR_SAME (&l->link_id, &w->id)) | |
0c0f9cd5 | 397 | return l; |
718e3744 | 398 | } |
399 | ||
400 | return NULL; | |
401 | } | |
402 | ||
75ee0b8e | 403 | /* |
404 | * Consider supplied next-hop for inclusion to the supplied list of | |
405 | * equal-cost next-hops, adjust list as neccessary. | |
406 | * | |
407 | * (Discussed on GNU Zebra list 27 May 2003, [zebra 19184]) | |
408 | * | |
409 | * Note that below is a bit of a hack, and limits ECMP to paths that go to | |
410 | * same nexthop. Where as paths via inequal output_cost interfaces could | |
411 | * still quite easily be ECMP due to remote cost differences. | |
412 | * | |
413 | * TODO: It really should be done by way of recording currently valid | |
414 | * backlinks and determining the appropriate nexthops from the list of | |
415 | * backlinks, or even simpler, just flushing nexthop list if we find a lower | |
416 | * cost path to a candidate vertex in SPF, maybe. | |
bf9392c6 | 417 | */ |
0c0f9cd5 | 418 | void |
419 | ospf_spf_consider_nexthop (struct list *nexthops, | |
420 | struct vertex_nexthop *newhop) | |
bf9392c6 | 421 | { |
bf9392c6 | 422 | struct vertex_nexthop *hop; |
75ee0b8e | 423 | struct listnode *ln, *nn; |
0c0f9cd5 | 424 | |
75ee0b8e | 425 | /* nexthop list should contain only the set of nexthops that have the lowest |
426 | * equal cost | |
427 | */ | |
428 | if (nexthops->head != NULL) | |
429 | { | |
430 | hop = getdata (nexthops->head); | |
431 | ||
432 | /* weed out hops with higher cost than the newhop */ | |
433 | if (hop->oi->output_cost > newhop->oi->output_cost) | |
434 | { | |
435 | /* delete the existing nexthops */ | |
436 | for (ln = nexthops->head; ln; ln = nn) | |
437 | { | |
438 | nn = ln->next; | |
439 | hop = getdata (ln); | |
440 | ||
441 | listnode_delete (nexthops, hop); | |
442 | vertex_nexthop_free (hop); | |
443 | } | |
444 | } | |
445 | else if (hop->oi->output_cost < newhop->oi->output_cost) | |
0c0f9cd5 | 446 | return; |
75ee0b8e | 447 | } |
0c0f9cd5 | 448 | |
bf9392c6 | 449 | /* new hop is <= existing hops, add it */ |
0c0f9cd5 | 450 | listnode_add (nexthops, newhop); |
bf9392c6 | 451 | |
452 | return; | |
453 | } | |
454 | ||
630e4807 | 455 | /* 16.1.1. Calculate nexthop from root through V (parent) to |
456 | * vertex W (destination). | |
457 | */ | |
718e3744 | 458 | void |
459 | ospf_nexthop_calculation (struct ospf_area *area, | |
460 | struct vertex *v, struct vertex *w) | |
461 | { | |
52dc7ee6 | 462 | struct listnode *node; |
718e3744 | 463 | struct vertex_nexthop *nh, *x; |
464 | struct ospf_interface *oi = NULL; | |
465 | struct router_lsa_link *l = NULL; | |
0c0f9cd5 | 466 | |
467 | ||
718e3744 | 468 | if (IS_DEBUG_OSPF_EVENT) |
630e4807 | 469 | { |
470 | zlog_info ("ospf_nexthop_calculation(): Start"); | |
471 | ospf_vertex_dump("V (parent):", v, 1, 1); | |
472 | ospf_vertex_dump("W (dest) :", w, 1, 1); | |
473 | } | |
718e3744 | 474 | |
718e3744 | 475 | if (v == area->spf) |
476 | { | |
630e4807 | 477 | /* 16.1.1 para 4. In the first case, the parent vertex (V) is the |
478 | root (the calculating router itself). This means that the | |
479 | destination is either a directly connected network or directly | |
480 | connected router. The outgoing interface in this case is simply | |
481 | the OSPF interface connecting to the destination network/router. | |
482 | */ | |
483 | ||
718e3744 | 484 | if (w->type == OSPF_VERTEX_ROUTER) |
0c0f9cd5 | 485 | { |
486 | while ((l = ospf_get_next_link (v, w, l))) | |
487 | { | |
630e4807 | 488 | /* l is a link from v to w |
489 | * l2 will be link from w to v | |
490 | */ | |
0c0f9cd5 | 491 | struct router_lsa_link *l2 = NULL; |
492 | ||
630e4807 | 493 | if (IS_DEBUG_OSPF_EVENT) |
494 | { | |
495 | char buf1[BUFSIZ]; | |
630e4807 | 496 | zlog_info("ospf_nexthop_calculation(): considering link " |
497 | "type %d link_id %s link_data %s", | |
498 | l->m[0].type, | |
499 | inet_ntop (AF_INET, &l->link_id, buf1, BUFSIZ), | |
500 | inet_ntop (AF_INET, &l->link_data, buf1, BUFSIZ)); | |
501 | } | |
502 | ||
0c0f9cd5 | 503 | if (l->m[0].type == LSA_LINK_TYPE_POINTOPOINT) |
504 | { | |
630e4807 | 505 | /* If the destination is a router which connects to |
506 | the calculating router via a Point-to-MultiPoint | |
507 | network, the destination's next hop IP address(es) | |
508 | can be determined by examining the destination's | |
509 | router-LSA: each link pointing back to the | |
510 | calculating router and having a Link Data field | |
511 | belonging to the Point-to-MultiPoint network | |
512 | provides an IP address of the next hop router. | |
513 | ||
514 | At this point l is a link from V to W, and V is the | |
515 | root ("us"). Find the local interface associated | |
516 | with l (its address is in l->link_data). If it | |
517 | is a point-to-multipoint interface, then look through | |
518 | the links in the opposite direction (W to V). If | |
519 | any of them have an address that lands within the | |
520 | subnet declared by the PtMP link, then that link | |
521 | is a constituent of the PtMP link, and its address is | |
522 | a nexthop address for V. | |
523 | */ | |
68980084 | 524 | oi = ospf_if_is_configured (area->ospf, &l->link_data); |
7afa08da | 525 | if (oi && oi->type == OSPF_IFTYPE_POINTOMULTIPOINT) |
0c0f9cd5 | 526 | { |
527 | struct prefix_ipv4 la; | |
630e4807 | 528 | |
529 | la.family = AF_INET; | |
0c0f9cd5 | 530 | la.prefixlen = oi->address->prefixlen; |
630e4807 | 531 | |
532 | /* V links to W on PtMP interface | |
533 | - find the interface address on W */ | |
0c0f9cd5 | 534 | while ((l2 = ospf_get_next_link (w, v, l2))) |
535 | { | |
536 | la.prefix = l2->link_data; | |
537 | ||
538 | if (prefix_cmp ((struct prefix *) &la, | |
539 | oi->address) == 0) | |
540 | /* link_data is on our PtMP network */ | |
541 | break; | |
542 | } | |
630e4807 | 543 | } /* end l is on point-to-multipoint link */ |
0c0f9cd5 | 544 | else |
545 | { | |
630e4807 | 546 | /* l is a regular point-to-point link. |
547 | Look for a link from W to V. | |
548 | */ | |
0c0f9cd5 | 549 | while ((l2 = ospf_get_next_link (w, v, l2))) |
550 | { | |
551 | oi = ospf_if_is_configured (area->ospf, | |
552 | &(l2->link_data)); | |
553 | ||
554 | if (oi == NULL) | |
555 | continue; | |
556 | ||
557 | if (!IPV4_ADDR_SAME (&oi->address->u.prefix4, | |
558 | &l->link_data)) | |
559 | continue; | |
560 | ||
561 | break; | |
562 | } | |
563 | } | |
564 | ||
565 | if (oi && l2) | |
566 | { | |
630e4807 | 567 | /* found all necessary info to build nexthop */ |
0c0f9cd5 | 568 | nh = vertex_nexthop_new (v); |
569 | nh->oi = oi; | |
570 | nh->router = l2->link_data; | |
571 | ospf_spf_consider_nexthop (w->nexthop, nh); | |
572 | } | |
630e4807 | 573 | else |
574 | { | |
575 | zlog_info("ospf_nexthop_calculation(): " | |
576 | "could not determine nexthop for link"); | |
577 | } | |
578 | } /* end point-to-point link from V to W */ | |
579 | } /* end iterate over links in W */ | |
580 | } /* end W is a Router vertex */ | |
718e3744 | 581 | else |
0c0f9cd5 | 582 | { |
630e4807 | 583 | assert(w->type == OSPF_VERTEX_NETWORK); |
0c0f9cd5 | 584 | while ((l = ospf_get_next_link (v, w, l))) |
585 | { | |
586 | oi = ospf_if_is_configured (area->ospf, &(l->link_data)); | |
587 | if (oi) | |
588 | { | |
589 | nh = vertex_nexthop_new (v); | |
590 | nh->oi = oi; | |
591 | nh->router.s_addr = 0; | |
75ee0b8e | 592 | ospf_spf_consider_nexthop (w->nexthop, nh); |
0c0f9cd5 | 593 | } |
594 | } | |
595 | } | |
718e3744 | 596 | return; |
630e4807 | 597 | } /* end V is the root */ |
598 | ||
599 | /* Check if W's parent is a network connected to root. */ | |
718e3744 | 600 | else if (v->type == OSPF_VERTEX_NETWORK) |
601 | { | |
630e4807 | 602 | /* See if any of V's parents are the root. */ |
718e3744 | 603 | for (node = listhead (v->nexthop); node; nextnode (node)) |
604 | { | |
630e4807 | 605 | x = (struct vertex_nexthop *) getdata (node); |
606 | if (x->parent == area->spf) /* connects to root? */ | |
607 | { | |
608 | /* 16.1.1 para 5. ...the parent vertex is a network that | |
609 | * directly connects the calculating router to the destination | |
610 | * router. The list of next hops is then determined by | |
611 | * examining the destination's router-LSA... | |
612 | */ | |
613 | ||
614 | assert(w->type == OSPF_VERTEX_ROUTER); | |
0c0f9cd5 | 615 | while ((l = ospf_get_next_link (w, v, l))) |
616 | { | |
630e4807 | 617 | /* ...For each link in the router-LSA that points back to the |
618 | * parent network, the link's Link Data field provides the IP | |
619 | * address of a next hop router. The outgoing interface to | |
620 | * use can then be derived from the next hop IP address (or | |
621 | * it can be inherited from the parent network). | |
622 | */ | |
0c0f9cd5 | 623 | nh = vertex_nexthop_new (v); |
624 | nh->oi = x->oi; | |
625 | nh->router = l->link_data; | |
75ee0b8e | 626 | ospf_spf_consider_nexthop (w->nexthop, nh); |
0c0f9cd5 | 627 | } |
628 | return; | |
629 | } | |
718e3744 | 630 | } |
631 | } | |
632 | ||
630e4807 | 633 | /* 16.1.1 para 4. If there is at least one intervening router in the |
634 | * current shortest path between the destination and the root, the | |
635 | * destination simply inherits the set of next hops from the | |
636 | * parent. | |
637 | */ | |
718e3744 | 638 | for (node = listhead (v->nexthop); node; nextnode (node)) |
639 | { | |
640 | nh = vertex_nexthop_dup (node->data); | |
641 | nh->parent = v; | |
642 | ospf_nexthop_add_unique (nh, w->nexthop); | |
643 | } | |
644 | } | |
645 | ||
630e4807 | 646 | /* Add a vertex to the SPF candidate list. */ |
718e3744 | 647 | void |
52dc7ee6 | 648 | ospf_install_candidate (struct list *candidate, struct vertex *w) |
718e3744 | 649 | { |
52dc7ee6 | 650 | struct listnode *node; |
718e3744 | 651 | struct vertex *cw; |
652 | ||
630e4807 | 653 | ospf_vertex_dump("ospf_install_candidate(): add to candidate list", w, 1, 1); |
654 | ||
718e3744 | 655 | if (list_isempty (candidate)) |
656 | { | |
657 | listnode_add (candidate, w); | |
658 | return; | |
659 | } | |
660 | ||
661 | /* Install vertex with sorting by distance. */ | |
662 | for (node = listhead (candidate); node; nextnode (node)) | |
663 | { | |
664 | cw = (struct vertex *) getdata (node); | |
665 | if (cw->distance > w->distance) | |
666 | { | |
667 | list_add_node_prev (candidate, node, w); | |
668 | break; | |
669 | } | |
670 | else if (node->next == NULL) | |
671 | { | |
672 | list_add_node_next (candidate, node, w); | |
673 | break; | |
674 | } | |
675 | } | |
630e4807 | 676 | |
677 | if (IS_DEBUG_OSPF_EVENT) | |
678 | { | |
679 | zlog_info("ospf_install_candidate(): candidate list now contains:"); | |
680 | for (node = listhead (candidate); node; nextnode (node)) | |
681 | { | |
682 | cw = (struct vertex *) getdata (node); | |
683 | ospf_vertex_dump(" candidate:", cw, 0, 0); | |
684 | } | |
685 | } | |
718e3744 | 686 | } |
687 | ||
630e4807 | 688 | /* RFC2328 Section 16.1 (2). |
689 | * v is on the SPF tree. Examine the links in v's LSA. Update the list | |
690 | * of candidates with any vertices not already on the list. If a lower-cost | |
691 | * path is found to a vertex already on the candidate list, store the new cost. | |
692 | */ | |
718e3744 | 693 | void |
694 | ospf_spf_next (struct vertex *v, struct ospf_area *area, | |
52dc7ee6 | 695 | struct list *candidate, struct route_table *rv, |
696 | struct route_table *nv) | |
718e3744 | 697 | { |
698 | struct ospf_lsa *w_lsa = NULL; | |
699 | struct vertex *w, *cw; | |
700 | u_char *p; | |
701 | u_char *lim; | |
702 | struct router_lsa_link *l = NULL; | |
703 | struct in_addr *r; | |
52dc7ee6 | 704 | struct listnode *node; |
718e3744 | 705 | int type = 0; |
706 | ||
707 | /* If this is a router-LSA, and bit V of the router-LSA (see Section | |
708 | A.4.2:RFC2328) is set, set Area A's TransitCapability to TRUE. */ | |
709 | if (v->type == OSPF_VERTEX_ROUTER) | |
710 | { | |
711 | if (IS_ROUTER_LSA_VIRTUAL ((struct router_lsa *) v->lsa)) | |
712 | area->transit = OSPF_TRANSIT_TRUE; | |
713 | } | |
714 | ||
715 | p = ((u_char *) v->lsa) + OSPF_LSA_HEADER_SIZE + 4; | |
0c0f9cd5 | 716 | lim = ((u_char *) v->lsa) + ntohs (v->lsa->length); |
717 | ||
718e3744 | 718 | while (p < lim) |
719 | { | |
d355bfa7 | 720 | int link = -1; /* link index for w's back link */ |
721 | ||
718e3744 | 722 | /* In case of V is Router-LSA. */ |
723 | if (v->lsa->type == OSPF_ROUTER_LSA) | |
724 | { | |
725 | l = (struct router_lsa_link *) p; | |
726 | ||
0c0f9cd5 | 727 | p += (ROUTER_LSA_MIN_SIZE + |
718e3744 | 728 | (l->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); |
729 | ||
730 | /* (a) If this is a link to a stub network, examine the next | |
731 | link in V's LSA. Links to stub networks will be | |
732 | considered in the second stage of the shortest path | |
733 | calculation. */ | |
734 | if ((type = l->m[0].type) == LSA_LINK_TYPE_STUB) | |
735 | continue; | |
736 | ||
737 | /* (b) Otherwise, W is a transit vertex (router or transit | |
738 | network). Look up the vertex W's LSA (router-LSA or | |
739 | network-LSA) in Area A's link state database. */ | |
740 | switch (type) | |
741 | { | |
742 | case LSA_LINK_TYPE_POINTOPOINT: | |
743 | case LSA_LINK_TYPE_VIRTUALLINK: | |
744 | if (type == LSA_LINK_TYPE_VIRTUALLINK) | |
0c0f9cd5 | 745 | { |
746 | if (IS_DEBUG_OSPF_EVENT) | |
747 | zlog_info ("looking up LSA through VL: %s", | |
748 | inet_ntoa (l->link_id)); | |
749 | } | |
718e3744 | 750 | |
751 | w_lsa = ospf_lsa_lookup (area, OSPF_ROUTER_LSA, l->link_id, | |
752 | l->link_id); | |
753 | if (w_lsa) | |
0c0f9cd5 | 754 | { |
755 | if (IS_DEBUG_OSPF_EVENT) | |
630e4807 | 756 | zlog_info ("found Router LSA %s", inet_ntoa (l->link_id)); |
0c0f9cd5 | 757 | } |
718e3744 | 758 | break; |
759 | case LSA_LINK_TYPE_TRANSIT: | |
0c0f9cd5 | 760 | if (IS_DEBUG_OSPF_EVENT) |
718e3744 | 761 | |
0c0f9cd5 | 762 | zlog_info ("Looking up Network LSA, ID: %s", |
763 | inet_ntoa (l->link_id)); | |
718e3744 | 764 | w_lsa = ospf_lsa_lookup_by_id (area, OSPF_NETWORK_LSA, |
0c0f9cd5 | 765 | l->link_id); |
718e3744 | 766 | if (w_lsa) |
0c0f9cd5 | 767 | if (IS_DEBUG_OSPF_EVENT) |
768 | zlog_info ("found the LSA"); | |
718e3744 | 769 | break; |
770 | default: | |
0c0f9cd5 | 771 | zlog_warn ("Invalid LSA link type %d", type); |
718e3744 | 772 | continue; |
773 | } | |
774 | } | |
775 | else | |
776 | { | |
777 | /* In case of V is Network-LSA. */ | |
0c0f9cd5 | 778 | r = (struct in_addr *) p; |
718e3744 | 779 | p += sizeof (struct in_addr); |
780 | ||
781 | /* Lookup the vertex W's LSA. */ | |
782 | w_lsa = ospf_lsa_lookup_by_id (area, OSPF_ROUTER_LSA, *r); | |
783 | } | |
784 | ||
785 | /* (b cont.) If the LSA does not exist, or its LS age is equal | |
786 | to MaxAge, or it does not have a link back to vertex V, | |
787 | examine the next link in V's LSA.[23] */ | |
788 | if (w_lsa == NULL) | |
789 | continue; | |
790 | ||
791 | if (IS_LSA_MAXAGE (w_lsa)) | |
792 | continue; | |
793 | ||
d355bfa7 | 794 | if ( (link = ospf_lsa_has_link (w_lsa->data, v->lsa)) < 0 ) |
718e3744 | 795 | { |
0c0f9cd5 | 796 | if (IS_DEBUG_OSPF_EVENT) |
797 | zlog_info ("The LSA doesn't have a link back"); | |
718e3744 | 798 | continue; |
799 | } | |
800 | ||
801 | /* (c) If vertex W is already on the shortest-path tree, examine | |
802 | the next link in the LSA. */ | |
803 | if (ospf_spf_has_vertex (rv, nv, w_lsa->data)) | |
804 | { | |
0c0f9cd5 | 805 | if (IS_DEBUG_OSPF_EVENT) |
806 | zlog_info ("The LSA is already in SPF"); | |
718e3744 | 807 | continue; |
808 | } | |
809 | ||
810 | /* (d) Calculate the link state cost D of the resulting path | |
811 | from the root to vertex W. D is equal to the sum of the link | |
812 | state cost of the (already calculated) shortest path to | |
813 | vertex V and the advertised cost of the link between vertices | |
814 | V and W. If D is: */ | |
815 | ||
816 | /* prepare vertex W. */ | |
817 | w = ospf_vertex_new (w_lsa); | |
818 | ||
d355bfa7 | 819 | /* Save W's back link index number, for use by virtual links */ |
820 | w->backlink = link; | |
821 | ||
718e3744 | 822 | /* calculate link cost D. */ |
823 | if (v->lsa->type == OSPF_ROUTER_LSA) | |
630e4807 | 824 | w->distance = v->distance + ntohs (l->m[0].metric); |
825 | else /* v is not a Router-LSA */ | |
826 | w->distance = v->distance; | |
718e3744 | 827 | |
828 | /* Is there already vertex W in candidate list? */ | |
829 | node = ospf_vertex_lookup (candidate, w->id, w->type); | |
830 | if (node == NULL) | |
831 | { | |
630e4807 | 832 | /* W is a new candidate. Calculate nexthop to W and add W |
833 | * to the candidate list. | |
834 | */ | |
718e3744 | 835 | ospf_nexthop_calculation (area, v, w); |
836 | ||
837 | ospf_install_candidate (candidate, w); | |
838 | } | |
839 | else | |
840 | { | |
630e4807 | 841 | /* W is already on the candidate list; call it cw. |
842 | * Compare the previously calculated cost (cw->distance) | |
843 | * with the cost we just determined (w->distance) to see | |
844 | * if we've found a shorter path. | |
845 | */ | |
718e3744 | 846 | cw = (struct vertex *) getdata (node); |
847 | ||
630e4807 | 848 | /* If the previous cost was lower, we didn't find a |
849 | * shorter path, so we're done with w. | |
850 | */ | |
718e3744 | 851 | if (cw->distance < w->distance) |
852 | { | |
853 | ospf_vertex_free (w); | |
854 | continue; | |
855 | } | |
718e3744 | 856 | else if (cw->distance == w->distance) |
857 | { | |
630e4807 | 858 | /* Found an equal-cost path to W. Calculate nexthop to W. */ |
718e3744 | 859 | ospf_nexthop_calculation (area, v, w); |
860 | ospf_nexthop_merge (cw->nexthop, w->nexthop); | |
861 | list_delete_all_node (w->nexthop); | |
862 | ospf_vertex_free (w); | |
863 | } | |
718e3744 | 864 | else |
865 | { | |
630e4807 | 866 | /* Found a lower-cost path to W. Calculate nexthop to W. */ |
718e3744 | 867 | ospf_nexthop_calculation (area, v, w); |
868 | ||
869 | /* Remove old vertex from candidate list. */ | |
870 | ospf_vertex_free (cw); | |
871 | listnode_delete (candidate, cw); | |
872 | ||
630e4807 | 873 | /* Install new W to candidate list. */ |
718e3744 | 874 | ospf_install_candidate (candidate, w); |
875 | } | |
630e4807 | 876 | } /* end W is already on the candidate list */ |
877 | } /* end loop over the links in V's LSA */ | |
718e3744 | 878 | } |
879 | ||
880 | /* Add vertex V to SPF tree. */ | |
881 | void | |
882 | ospf_spf_register (struct vertex *v, struct route_table *rv, | |
0c0f9cd5 | 883 | struct route_table *nv) |
718e3744 | 884 | { |
885 | struct prefix p; | |
886 | struct route_node *rn; | |
887 | ||
630e4807 | 888 | ospf_vertex_dump("ospf_spf_register(): adding to SPF tree:", v, 1, 1); |
889 | ||
718e3744 | 890 | p.family = AF_INET; |
891 | p.prefixlen = IPV4_MAX_BITLEN; | |
892 | p.u.prefix4 = v->id; | |
893 | ||
894 | if (v->type == OSPF_VERTEX_ROUTER) | |
895 | rn = route_node_get (rv, &p); | |
896 | else | |
897 | rn = route_node_get (nv, &p); | |
898 | ||
899 | rn->info = v; | |
900 | } | |
901 | ||
902 | void | |
903 | ospf_spf_route_free (struct route_table *table) | |
904 | { | |
905 | struct route_node *rn; | |
906 | struct vertex *v; | |
907 | ||
908 | for (rn = route_top (table); rn; rn = route_next (rn)) | |
909 | { | |
910 | if ((v = rn->info)) | |
0c0f9cd5 | 911 | { |
912 | ospf_vertex_free (v); | |
913 | rn->info = NULL; | |
914 | } | |
718e3744 | 915 | |
916 | route_unlock_node (rn); | |
917 | } | |
918 | ||
919 | route_table_finish (table); | |
920 | } | |
921 | ||
922 | void | |
923 | ospf_spf_dump (struct vertex *v, int i) | |
924 | { | |
52dc7ee6 | 925 | struct listnode *cnode; |
926 | struct listnode *nnode; | |
718e3744 | 927 | struct vertex_nexthop *nexthop; |
928 | ||
929 | if (v->type == OSPF_VERTEX_ROUTER) | |
930 | { | |
931 | if (IS_DEBUG_OSPF_EVENT) | |
0c0f9cd5 | 932 | zlog_info ("SPF Result: %d [R] %s", i, inet_ntoa (v->lsa->id)); |
718e3744 | 933 | } |
934 | else | |
935 | { | |
936 | struct network_lsa *lsa = (struct network_lsa *) v->lsa; | |
937 | if (IS_DEBUG_OSPF_EVENT) | |
0c0f9cd5 | 938 | zlog_info ("SPF Result: %d [N] %s/%d", i, inet_ntoa (v->lsa->id), |
939 | ip_masklen (lsa->mask)); | |
630e4807 | 940 | } |
718e3744 | 941 | |
630e4807 | 942 | for (nnode = listhead (v->nexthop); nnode; nextnode (nnode)) |
943 | { | |
944 | nexthop = getdata (nnode); | |
945 | if (IS_DEBUG_OSPF_EVENT) | |
946 | zlog_info (" nexthop %s", inet_ntoa (nexthop->router)); | |
718e3744 | 947 | } |
948 | ||
949 | i++; | |
950 | ||
951 | for (cnode = listhead (v->child); cnode; nextnode (cnode)) | |
952 | { | |
953 | v = getdata (cnode); | |
954 | ospf_spf_dump (v, i); | |
955 | } | |
956 | } | |
957 | ||
958 | /* Second stage of SPF calculation. */ | |
959 | void | |
0c0f9cd5 | 960 | ospf_spf_process_stubs (struct ospf_area *area, struct vertex *v, |
718e3744 | 961 | struct route_table *rt) |
962 | { | |
52dc7ee6 | 963 | struct listnode *cnode; |
718e3744 | 964 | struct vertex *child; |
965 | ||
966 | if (IS_DEBUG_OSPF_EVENT) | |
967 | zlog_info ("ospf_process_stub():processing stubs for area %s", | |
0c0f9cd5 | 968 | inet_ntoa (area->area_id)); |
718e3744 | 969 | if (v->type == OSPF_VERTEX_ROUTER) |
970 | { | |
971 | u_char *p; | |
972 | u_char *lim; | |
973 | struct router_lsa_link *l; | |
974 | struct router_lsa *rlsa; | |
975 | ||
0c0f9cd5 | 976 | if (IS_DEBUG_OSPF_EVENT) |
630e4807 | 977 | zlog_info ("ospf_process_stubs():processing router LSA, id: %s", |
0c0f9cd5 | 978 | inet_ntoa (v->lsa->id)); |
718e3744 | 979 | rlsa = (struct router_lsa *) v->lsa; |
980 | ||
981 | ||
0c0f9cd5 | 982 | if (IS_DEBUG_OSPF_EVENT) |
630e4807 | 983 | zlog_info ("ospf_process_stubs(): we have %d links to process", |
0c0f9cd5 | 984 | ntohs (rlsa->links)); |
630e4807 | 985 | p = ((u_char *) v->lsa) + OSPF_LSA_HEADER_SIZE + 4; |
718e3744 | 986 | lim = ((u_char *) v->lsa) + ntohs (v->lsa->length); |
987 | ||
988 | while (p < lim) | |
989 | { | |
990 | l = (struct router_lsa_link *) p; | |
991 | ||
992 | p += (ROUTER_LSA_MIN_SIZE + | |
993 | (l->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); | |
994 | ||
995 | if (l->m[0].type == LSA_LINK_TYPE_STUB) | |
996 | ospf_intra_add_stub (rt, l, v, area); | |
997 | } | |
998 | } | |
999 | ||
630e4807 | 1000 | ospf_vertex_dump("ospf_process_stubs(): after examining links: ", v, 1, 1); |
718e3744 | 1001 | |
1002 | for (cnode = listhead (v->child); cnode; nextnode (cnode)) | |
1003 | { | |
1004 | child = getdata (cnode); | |
1005 | ||
1006 | if (CHECK_FLAG (child->flags, OSPF_VERTEX_PROCESSED)) | |
0c0f9cd5 | 1007 | continue; |
718e3744 | 1008 | |
1009 | ospf_spf_process_stubs (area, child, rt); | |
1010 | ||
1011 | SET_FLAG (child->flags, OSPF_VERTEX_PROCESSED); | |
1012 | } | |
1013 | } | |
1014 | ||
1015 | void | |
1016 | ospf_rtrs_free (struct route_table *rtrs) | |
1017 | { | |
1018 | struct route_node *rn; | |
52dc7ee6 | 1019 | struct list *or_list; |
1020 | struct listnode *node; | |
718e3744 | 1021 | |
1022 | if (IS_DEBUG_OSPF_EVENT) | |
0c0f9cd5 | 1023 | zlog_info ("Route: Router Routing Table free"); |
718e3744 | 1024 | |
1025 | for (rn = route_top (rtrs); rn; rn = route_next (rn)) | |
1026 | if ((or_list = rn->info) != NULL) | |
1027 | { | |
0c0f9cd5 | 1028 | for (node = listhead (or_list); node; nextnode (node)) |
1029 | ospf_route_free (node->data); | |
718e3744 | 1030 | |
0c0f9cd5 | 1031 | list_delete (or_list); |
718e3744 | 1032 | |
0c0f9cd5 | 1033 | /* Unlock the node. */ |
1034 | rn->info = NULL; | |
1035 | route_unlock_node (rn); | |
718e3744 | 1036 | } |
1037 | route_table_finish (rtrs); | |
1038 | } | |
1039 | ||
1040 | void | |
1041 | ospf_rtrs_print (struct route_table *rtrs) | |
1042 | { | |
1043 | struct route_node *rn; | |
52dc7ee6 | 1044 | struct list *or_list; |
1045 | struct listnode *ln; | |
1046 | struct listnode *pnode; | |
718e3744 | 1047 | struct ospf_route *or; |
1048 | struct ospf_path *path; | |
1049 | char buf1[BUFSIZ]; | |
1050 | char buf2[BUFSIZ]; | |
1051 | ||
1052 | if (IS_DEBUG_OSPF_EVENT) | |
1053 | zlog_info ("ospf_rtrs_print() start"); | |
1054 | ||
1055 | for (rn = route_top (rtrs); rn; rn = route_next (rn)) | |
1056 | if ((or_list = rn->info) != NULL) | |
1057 | for (ln = listhead (or_list); ln; nextnode (ln)) | |
1058 | { | |
1059 | or = getdata (ln); | |
1060 | ||
1061 | switch (or->path_type) | |
1062 | { | |
1063 | case OSPF_PATH_INTRA_AREA: | |
0c0f9cd5 | 1064 | if (IS_DEBUG_OSPF_EVENT) |
1065 | zlog_info ("%s [%d] area: %s", | |
1066 | inet_ntop (AF_INET, &or->id, buf1, BUFSIZ), | |
1067 | or->cost, inet_ntop (AF_INET, &or->u.std.area_id, | |
1068 | buf2, BUFSIZ)); | |
718e3744 | 1069 | break; |
1070 | case OSPF_PATH_INTER_AREA: | |
0c0f9cd5 | 1071 | if (IS_DEBUG_OSPF_EVENT) |
1072 | zlog_info ("%s IA [%d] area: %s", | |
1073 | inet_ntop (AF_INET, &or->id, buf1, BUFSIZ), | |
1074 | or->cost, inet_ntop (AF_INET, &or->u.std.area_id, | |
1075 | buf2, BUFSIZ)); | |
718e3744 | 1076 | break; |
1077 | default: | |
1078 | break; | |
1079 | } | |
1080 | ||
96735eea | 1081 | for (pnode = listhead (or->paths); pnode; nextnode (pnode)) |
718e3744 | 1082 | { |
1083 | path = getdata (pnode); | |
1084 | if (path->nexthop.s_addr == 0) | |
0c0f9cd5 | 1085 | { |
1086 | if (IS_DEBUG_OSPF_EVENT) | |
1087 | zlog_info (" directly attached to %s\r\n", | |
1088 | IF_NAME (path->oi)); | |
1089 | } | |
1090 | else | |
1091 | { | |
1092 | if (IS_DEBUG_OSPF_EVENT) | |
1093 | zlog_info (" via %s, %s\r\n", | |
1094 | inet_ntoa (path->nexthop), IF_NAME (path->oi)); | |
1095 | } | |
718e3744 | 1096 | } |
1097 | } | |
1098 | ||
1099 | zlog_info ("ospf_rtrs_print() end"); | |
1100 | } | |
1101 | ||
1102 | /* Calculating the shortest-path tree for an area. */ | |
1103 | void | |
0c0f9cd5 | 1104 | ospf_spf_calculate (struct ospf_area *area, struct route_table *new_table, |
718e3744 | 1105 | struct route_table *new_rtrs) |
1106 | { | |
52dc7ee6 | 1107 | struct list *candidate; |
1108 | struct listnode *node; | |
718e3744 | 1109 | struct vertex *v; |
1110 | struct route_table *rv; | |
1111 | struct route_table *nv; | |
1112 | ||
1113 | if (IS_DEBUG_OSPF_EVENT) | |
1114 | { | |
1115 | zlog_info ("ospf_spf_calculate: Start"); | |
0c0f9cd5 | 1116 | zlog_info ("ospf_spf_calculate: running Dijkstra for area %s", |
1117 | inet_ntoa (area->area_id)); | |
718e3744 | 1118 | } |
1119 | ||
1120 | /* Check router-lsa-self. If self-router-lsa is not yet allocated, | |
1121 | return this area's calculation. */ | |
0c0f9cd5 | 1122 | if (!area->router_lsa_self) |
718e3744 | 1123 | { |
1124 | if (IS_DEBUG_OSPF_EVENT) | |
0c0f9cd5 | 1125 | zlog_info ("ospf_spf_calculate: " |
1126 | "Skip area %s's calculation due to empty router_lsa_self", | |
1127 | inet_ntoa (area->area_id)); | |
718e3744 | 1128 | return; |
1129 | } | |
1130 | ||
1131 | /* RFC2328 16.1. (1). */ | |
0c0f9cd5 | 1132 | /* Initialize the algorithm's data structures. */ |
718e3744 | 1133 | rv = route_table_init (); |
1134 | nv = route_table_init (); | |
1135 | ||
0c0f9cd5 | 1136 | /* Clear the list of candidate vertices. */ |
718e3744 | 1137 | candidate = list_new (); |
1138 | ||
1139 | /* Initialize the shortest-path tree to only the root (which is the | |
1140 | router doing the calculation). */ | |
1141 | ospf_spf_init (area); | |
1142 | v = area->spf; | |
1143 | ospf_spf_register (v, rv, nv); | |
1144 | ||
1145 | /* Set Area A's TransitCapability to FALSE. */ | |
1146 | area->transit = OSPF_TRANSIT_FALSE; | |
1147 | area->shortcut_capability = 1; | |
1148 | ||
1149 | for (;;) | |
1150 | { | |
1151 | /* RFC2328 16.1. (2). */ | |
1152 | ospf_spf_next (v, area, candidate, rv, nv); | |
1153 | ||
1154 | /* RFC2328 16.1. (3). */ | |
1155 | /* If at this step the candidate list is empty, the shortest- | |
1156 | path tree (of transit vertices) has been completely built and | |
1157 | this stage of the procedure terminates. */ | |
1158 | if (listcount (candidate) == 0) | |
1159 | break; | |
1160 | ||
1161 | /* Otherwise, choose the vertex belonging to the candidate list | |
1162 | that is closest to the root, and add it to the shortest-path | |
1163 | tree (removing it from the candidate list in the | |
0c0f9cd5 | 1164 | process). */ |
718e3744 | 1165 | node = listhead (candidate); |
1166 | v = getdata (node); | |
1167 | ospf_vertex_add_parent (v); | |
1168 | ||
630e4807 | 1169 | /* Remove from the candidate list. */ |
718e3744 | 1170 | listnode_delete (candidate, v); |
1171 | ||
1172 | /* Add to SPF tree. */ | |
1173 | ospf_spf_register (v, rv, nv); | |
1174 | ||
1175 | /* Note that when there is a choice of vertices closest to the | |
1176 | root, network vertices must be chosen before router vertices | |
1177 | in order to necessarily find all equal-cost paths. */ | |
1178 | /* We don't do this at this moment, we should add the treatment | |
1179 | above codes. -- kunihiro. */ | |
1180 | ||
1181 | /* RFC2328 16.1. (4). */ | |
1182 | if (v->type == OSPF_VERTEX_ROUTER) | |
1183 | ospf_intra_add_router (new_rtrs, v, area); | |
0c0f9cd5 | 1184 | else |
718e3744 | 1185 | ospf_intra_add_transit (new_table, v, area); |
1186 | ||
1187 | /* RFC2328 16.1. (5). */ | |
1188 | /* Iterate the algorithm by returning to Step 2. */ | |
630e4807 | 1189 | |
1190 | } /* end loop until no more candidate vertices */ | |
718e3744 | 1191 | |
1192 | if (IS_DEBUG_OSPF_EVENT) | |
1193 | { | |
1194 | ospf_spf_dump (area->spf, 0); | |
1195 | ospf_route_table_dump (new_table); | |
1196 | } | |
1197 | ||
1198 | /* Second stage of SPF calculation procedure's */ | |
1199 | ospf_spf_process_stubs (area, area->spf, new_table); | |
1200 | ||
1201 | /* Free all vertices which allocated for SPF calculation */ | |
1202 | ospf_spf_route_free (rv); | |
1203 | ospf_spf_route_free (nv); | |
1204 | ||
1205 | /* Free candidate list */ | |
1206 | list_free (candidate); | |
1207 | ||
1208 | /* Increment SPF Calculation Counter. */ | |
1209 | area->spf_calculation++; | |
1210 | ||
68980084 | 1211 | area->ospf->ts_spf = time (NULL); |
718e3744 | 1212 | |
1213 | if (IS_DEBUG_OSPF_EVENT) | |
1214 | zlog_info ("ospf_spf_calculate: Stop"); | |
1215 | } | |
1216 | \f | |
1217 | /* Timer for SPF calculation. */ | |
1218 | int | |
68980084 | 1219 | ospf_spf_calculate_timer (struct thread *thread) |
718e3744 | 1220 | { |
68980084 | 1221 | struct ospf *ospf = THREAD_ARG (thread); |
718e3744 | 1222 | struct route_table *new_table, *new_rtrs; |
52dc7ee6 | 1223 | struct listnode *node; |
718e3744 | 1224 | |
1225 | if (IS_DEBUG_OSPF_EVENT) | |
1226 | zlog_info ("SPF: Timer (SPF calculation expire)"); | |
0c0f9cd5 | 1227 | |
718e3744 | 1228 | ospf->t_spf_calc = NULL; |
1229 | ||
1230 | /* Allocate new table tree. */ | |
1231 | new_table = route_table_init (); | |
0c0f9cd5 | 1232 | new_rtrs = route_table_init (); |
718e3744 | 1233 | |
68980084 | 1234 | ospf_vl_unapprove (ospf); |
718e3744 | 1235 | |
1236 | /* Calculate SPF for each area. */ | |
1237 | for (node = listhead (ospf->areas); node; node = nextnode (node)) | |
1238 | ospf_spf_calculate (node->data, new_table, new_rtrs); | |
1239 | ||
68980084 | 1240 | ospf_vl_shut_unapproved (ospf); |
718e3744 | 1241 | |
68980084 | 1242 | ospf_ia_routing (ospf, new_table, new_rtrs); |
718e3744 | 1243 | |
1244 | ospf_prune_unreachable_networks (new_table); | |
1245 | ospf_prune_unreachable_routers (new_rtrs); | |
1246 | ||
1247 | /* AS-external-LSA calculation should not be performed here. */ | |
1248 | ||
1249 | /* If new Router Route is installed, | |
1250 | then schedule re-calculate External routes. */ | |
1251 | if (1) | |
68980084 | 1252 | ospf_ase_calculate_schedule (ospf); |
718e3744 | 1253 | |
68980084 | 1254 | ospf_ase_calculate_timer_add (ospf); |
718e3744 | 1255 | |
1256 | /* Update routing table. */ | |
68980084 | 1257 | ospf_route_install (ospf, new_table); |
718e3744 | 1258 | |
1259 | /* Update ABR/ASBR routing table */ | |
68980084 | 1260 | if (ospf->old_rtrs) |
718e3744 | 1261 | { |
1262 | /* old_rtrs's node holds linked list of ospf_route. --kunihiro. */ | |
68980084 | 1263 | /* ospf_route_delete (ospf->old_rtrs); */ |
1264 | ospf_rtrs_free (ospf->old_rtrs); | |
718e3744 | 1265 | } |
1266 | ||
68980084 | 1267 | ospf->old_rtrs = ospf->new_rtrs; |
1268 | ospf->new_rtrs = new_rtrs; | |
718e3744 | 1269 | |
0c0f9cd5 | 1270 | if (IS_OSPF_ABR (ospf)) |
68980084 | 1271 | ospf_abr_task (ospf); |
718e3744 | 1272 | |
1273 | if (IS_DEBUG_OSPF_EVENT) | |
1274 | zlog_info ("SPF: calculation complete"); | |
1275 | ||
1276 | return 0; | |
1277 | } | |
1278 | ||
1279 | /* Add schedule for SPF calculation. To avoid frequenst SPF calc, we | |
1280 | set timer for SPF calc. */ | |
1281 | void | |
68980084 | 1282 | ospf_spf_calculate_schedule (struct ospf *ospf) |
718e3744 | 1283 | { |
1284 | time_t ht, delay; | |
1285 | ||
1286 | if (IS_DEBUG_OSPF_EVENT) | |
1287 | zlog_info ("SPF: calculation timer scheduled"); | |
1288 | ||
1289 | /* OSPF instance does not exist. */ | |
68980084 | 1290 | if (ospf == NULL) |
718e3744 | 1291 | return; |
1292 | ||
1293 | /* SPF calculation timer is already scheduled. */ | |
68980084 | 1294 | if (ospf->t_spf_calc) |
718e3744 | 1295 | { |
1296 | if (IS_DEBUG_OSPF_EVENT) | |
0c0f9cd5 | 1297 | zlog_info ("SPF: calculation timer is already scheduled: %p", |
1298 | ospf->t_spf_calc); | |
718e3744 | 1299 | return; |
1300 | } | |
1301 | ||
68980084 | 1302 | ht = time (NULL) - ospf->ts_spf; |
718e3744 | 1303 | |
1304 | /* Get SPF calculation delay time. */ | |
68980084 | 1305 | if (ht < ospf->spf_holdtime) |
718e3744 | 1306 | { |
68980084 | 1307 | if (ospf->spf_holdtime - ht < ospf->spf_delay) |
0c0f9cd5 | 1308 | delay = ospf->spf_delay; |
718e3744 | 1309 | else |
0c0f9cd5 | 1310 | delay = ospf->spf_holdtime - ht; |
718e3744 | 1311 | } |
1312 | else | |
68980084 | 1313 | delay = ospf->spf_delay; |
718e3744 | 1314 | |
1315 | if (IS_DEBUG_OSPF_EVENT) | |
fa2b17e3 | 1316 | zlog_info ("SPF: calculation timer delay = %ld", (long)delay); |
68980084 | 1317 | ospf->t_spf_calc = |
1318 | thread_add_timer (master, ospf_spf_calculate_timer, ospf, delay); | |
718e3744 | 1319 | } |