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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 () */ | |
462f20d5 | 32 | #include "pqueue.h" |
718e3744 | 33 | |
34 | #include "ospfd/ospfd.h" | |
35 | #include "ospfd/ospf_interface.h" | |
36 | #include "ospfd/ospf_ism.h" | |
37 | #include "ospfd/ospf_asbr.h" | |
38 | #include "ospfd/ospf_lsa.h" | |
39 | #include "ospfd/ospf_lsdb.h" | |
40 | #include "ospfd/ospf_neighbor.h" | |
41 | #include "ospfd/ospf_nsm.h" | |
42 | #include "ospfd/ospf_spf.h" | |
43 | #include "ospfd/ospf_route.h" | |
44 | #include "ospfd/ospf_ia.h" | |
45 | #include "ospfd/ospf_ase.h" | |
46 | #include "ospfd/ospf_abr.h" | |
47 | #include "ospfd/ospf_dump.h" | |
48 | ||
49 | #define DEBUG | |
50 | ||
462f20d5 | 51 | /* Heap related functions, for the managment of the candidates, to |
52 | * be used with pqueue. */ | |
53 | static int | |
54 | cmp (void * node1 , void * node2) | |
55 | { | |
56 | struct vertex * v1 = (struct vertex *) node1; | |
57 | struct vertex * v2 = (struct vertex *) node2; | |
58 | if (v1 != NULL && v2 != NULL ) | |
59 | return (v1->distance - v2->distance); | |
60 | else | |
61 | return 0; | |
62 | } | |
63 | ||
64 | static void | |
65 | update_stat (void * node , int position) | |
66 | { | |
67 | struct vertex * v = (struct vertex *) node; | |
68 | /* Set the status of the vertex, when its position changes. */ | |
69 | *(v->stat) = position; | |
70 | } | |
71 | /* End of the heap related functions. */ | |
72 | ||
4dadc291 | 73 | static struct vertex_nexthop * |
718e3744 | 74 | vertex_nexthop_new (struct vertex *parent) |
75 | { | |
76 | struct vertex_nexthop *new; | |
77 | ||
78 | new = XCALLOC (MTYPE_OSPF_NEXTHOP, sizeof (struct vertex_nexthop)); | |
79 | new->parent = parent; | |
80 | ||
81 | return new; | |
82 | } | |
83 | ||
4dadc291 | 84 | static void |
718e3744 | 85 | vertex_nexthop_free (struct vertex_nexthop *nh) |
86 | { | |
87 | XFREE (MTYPE_OSPF_NEXTHOP, nh); | |
88 | } | |
89 | ||
4dadc291 | 90 | static struct vertex_nexthop * |
718e3744 | 91 | vertex_nexthop_dup (struct vertex_nexthop *nh) |
92 | { | |
93 | struct vertex_nexthop *new; | |
94 | ||
95 | new = vertex_nexthop_new (nh->parent); | |
96 | ||
97 | new->oi = nh->oi; | |
98 | new->router = nh->router; | |
99 | ||
100 | return new; | |
101 | } | |
718e3744 | 102 | \f |
0c0f9cd5 | 103 | |
4dadc291 | 104 | static struct vertex * |
718e3744 | 105 | ospf_vertex_new (struct ospf_lsa *lsa) |
106 | { | |
107 | struct vertex *new; | |
108 | ||
109 | new = XMALLOC (MTYPE_OSPF_VERTEX, sizeof (struct vertex)); | |
110 | memset (new, 0, sizeof (struct vertex)); | |
111 | ||
112 | new->flags = 0; | |
462f20d5 | 113 | new->stat = &(lsa->stat); |
718e3744 | 114 | new->type = lsa->data->type; |
115 | new->id = lsa->data->id; | |
116 | new->lsa = lsa->data; | |
117 | new->distance = 0; | |
118 | new->child = list_new (); | |
119 | new->nexthop = list_new (); | |
d355bfa7 | 120 | new->backlink = -1; |
718e3744 | 121 | |
122 | return new; | |
123 | } | |
124 | ||
4dadc291 | 125 | static void |
718e3744 | 126 | ospf_vertex_free (struct vertex *v) |
127 | { | |
1eb8ef25 | 128 | struct listnode *node, *nnode; |
129 | struct vertex_nexthop *nh; | |
718e3744 | 130 | |
131 | list_delete (v->child); | |
132 | ||
133 | if (listcount (v->nexthop) > 0) | |
1eb8ef25 | 134 | for (ALL_LIST_ELEMENTS (v->nexthop, node, nnode, nh)) |
135 | vertex_nexthop_free (nh); | |
718e3744 | 136 | |
137 | list_delete (v->nexthop); | |
138 | ||
139 | XFREE (MTYPE_OSPF_VERTEX, v); | |
140 | } | |
141 | ||
4dadc291 | 142 | static void |
eb1ce605 | 143 | ospf_vertex_dump(const char *msg, struct vertex *v, |
630e4807 | 144 | int print_nexthops, int print_children) |
145 | { | |
146 | if ( ! IS_DEBUG_OSPF_EVENT) | |
147 | return; | |
148 | ||
2a42e285 | 149 | zlog_debug("%s %s vertex %s distance %u backlink %d flags %u", |
630e4807 | 150 | msg, |
151 | v->type == OSPF_VERTEX_ROUTER ? "Router" : "Network", | |
152 | inet_ntoa(v->lsa->id), | |
153 | v->distance, | |
154 | v->backlink, | |
155 | (unsigned int)v->flags); | |
156 | ||
157 | if (print_nexthops) | |
158 | { | |
1eb8ef25 | 159 | struct listnode *node; |
160 | struct vertex_nexthop *nexthop; | |
161 | ||
162 | for (ALL_LIST_ELEMENTS_RO (v->nexthop, node, nexthop)) | |
630e4807 | 163 | { |
164 | char buf1[BUFSIZ]; | |
165 | char buf2[BUFSIZ]; | |
630e4807 | 166 | |
630e4807 | 167 | if (nexthop) |
168 | { | |
2a42e285 | 169 | zlog_debug (" nexthop %s interface %s parent %s", |
630e4807 | 170 | inet_ntop(AF_INET, &nexthop->router, buf1, BUFSIZ), |
171 | nexthop->oi ? IF_NAME(nexthop->oi) : "NULL", | |
172 | nexthop->parent ? inet_ntop(AF_INET, | |
173 | &nexthop->parent->id, | |
174 | buf2, BUFSIZ) | |
175 | : "NULL"); | |
176 | } | |
177 | } | |
178 | } | |
179 | ||
180 | if (print_children) | |
181 | { | |
52dc7ee6 | 182 | struct listnode *cnode; |
1eb8ef25 | 183 | struct vertex *cv; |
184 | ||
185 | for (ALL_LIST_ELEMENTS_RO (v->child, cnode, cv)) | |
186 | ospf_vertex_dump(" child:", cv, 0, 0); | |
630e4807 | 187 | } |
188 | } | |
189 | ||
190 | ||
191 | /* Add a vertex to the list of children in each of its parents. */ | |
4dadc291 | 192 | static void |
718e3744 | 193 | ospf_vertex_add_parent (struct vertex *v) |
194 | { | |
195 | struct vertex_nexthop *nh; | |
52dc7ee6 | 196 | struct listnode *node; |
718e3744 | 197 | |
1eb8ef25 | 198 | for (ALL_LIST_ELEMENTS_RO (v->nexthop, node, nh)) |
718e3744 | 199 | { |
718e3744 | 200 | /* No need to add two links from the same parent. */ |
201 | if (listnode_lookup (nh->parent->child, v) == NULL) | |
0c0f9cd5 | 202 | listnode_add (nh->parent->child, v); |
718e3744 | 203 | } |
204 | } | |
205 | \f | |
4dadc291 | 206 | static void |
718e3744 | 207 | ospf_spf_init (struct ospf_area *area) |
208 | { | |
209 | struct vertex *v; | |
210 | ||
211 | /* Create root node. */ | |
212 | v = ospf_vertex_new (area->router_lsa_self); | |
213 | ||
214 | area->spf = v; | |
215 | ||
216 | /* Reset ABR and ASBR router counts. */ | |
217 | area->abr_count = 0; | |
218 | area->asbr_count = 0; | |
219 | } | |
220 | ||
d355bfa7 | 221 | /* return index of link back to V from W, or -1 if no link found */ |
4dadc291 | 222 | static int |
718e3744 | 223 | ospf_lsa_has_link (struct lsa_header *w, struct lsa_header *v) |
224 | { | |
eb1ce605 | 225 | unsigned int i, length; |
718e3744 | 226 | struct router_lsa *rl; |
227 | struct network_lsa *nl; | |
228 | ||
229 | /* In case of W is Network LSA. */ | |
230 | if (w->type == OSPF_NETWORK_LSA) | |
231 | { | |
232 | if (v->type == OSPF_NETWORK_LSA) | |
d355bfa7 | 233 | return -1; |
718e3744 | 234 | |
235 | nl = (struct network_lsa *) w; | |
236 | length = (ntohs (w->length) - OSPF_LSA_HEADER_SIZE - 4) / 4; | |
0c0f9cd5 | 237 | |
718e3744 | 238 | for (i = 0; i < length; i++) |
239 | if (IPV4_ADDR_SAME (&nl->routers[i], &v->id)) | |
d355bfa7 | 240 | return i; |
241 | return -1; | |
718e3744 | 242 | } |
243 | ||
244 | /* In case of W is Router LSA. */ | |
245 | if (w->type == OSPF_ROUTER_LSA) | |
246 | { | |
247 | rl = (struct router_lsa *) w; | |
248 | ||
249 | length = ntohs (w->length); | |
250 | ||
251 | for (i = 0; | |
0c0f9cd5 | 252 | i < ntohs (rl->links) && length >= sizeof (struct router_lsa); |
253 | i++, length -= 12) | |
718e3744 | 254 | { |
255 | switch (rl->link[i].type) | |
256 | { | |
257 | case LSA_LINK_TYPE_POINTOPOINT: | |
258 | case LSA_LINK_TYPE_VIRTUALLINK: | |
259 | /* Router LSA ID. */ | |
260 | if (v->type == OSPF_ROUTER_LSA && | |
261 | IPV4_ADDR_SAME (&rl->link[i].link_id, &v->id)) | |
262 | { | |
d355bfa7 | 263 | return i; |
718e3744 | 264 | } |
265 | break; | |
266 | case LSA_LINK_TYPE_TRANSIT: | |
267 | /* Network LSA ID. */ | |
268 | if (v->type == OSPF_NETWORK_LSA && | |
269 | IPV4_ADDR_SAME (&rl->link[i].link_id, &v->id)) | |
270 | { | |
d355bfa7 | 271 | return i; |
0c0f9cd5 | 272 | } |
718e3744 | 273 | break; |
274 | case LSA_LINK_TYPE_STUB: | |
275 | /* Not take into count? */ | |
276 | continue; | |
277 | default: | |
278 | break; | |
279 | } | |
280 | } | |
281 | } | |
d355bfa7 | 282 | return -1; |
718e3744 | 283 | } |
284 | ||
285 | /* Add the nexthop to the list, only if it is unique. | |
286 | * If it's not unique, free the nexthop entry. | |
287 | */ | |
4dadc291 | 288 | static void |
52dc7ee6 | 289 | ospf_nexthop_add_unique (struct vertex_nexthop *new, struct list *nexthop) |
718e3744 | 290 | { |
291 | struct vertex_nexthop *nh; | |
52dc7ee6 | 292 | struct listnode *node; |
718e3744 | 293 | int match; |
294 | ||
295 | match = 0; | |
718e3744 | 296 | |
1eb8ef25 | 297 | for (ALL_LIST_ELEMENTS_RO (nexthop, node, nh)) |
298 | { | |
718e3744 | 299 | /* Compare the two entries. */ |
300 | /* XXX | |
301 | * Comparing the parent preserves the shortest path tree | |
302 | * structure even when the nexthops are identical. | |
303 | */ | |
304 | if (nh->oi == new->oi && | |
0c0f9cd5 | 305 | IPV4_ADDR_SAME (&nh->router, &new->router) && |
306 | nh->parent == new->parent) | |
307 | { | |
308 | match = 1; | |
309 | break; | |
310 | } | |
718e3744 | 311 | } |
312 | ||
313 | if (!match) | |
314 | listnode_add (nexthop, new); | |
315 | else | |
316 | vertex_nexthop_free (new); | |
317 | } | |
318 | ||
319 | /* Merge entries in list b into list a. */ | |
4dadc291 | 320 | static void |
52dc7ee6 | 321 | ospf_nexthop_merge (struct list *a, struct list *b) |
718e3744 | 322 | { |
1eb8ef25 | 323 | struct listnode *node, *nnode; |
324 | struct vertex_nexthop *nh; | |
718e3744 | 325 | |
1eb8ef25 | 326 | for (ALL_LIST_ELEMENTS (b, node, nnode, nh)) |
327 | ospf_nexthop_add_unique (nh, a); | |
718e3744 | 328 | } |
329 | ||
330 | #define ROUTER_LSA_MIN_SIZE 12 | |
331 | #define ROUTER_LSA_TOS_SIZE 4 | |
332 | ||
630e4807 | 333 | /* Find the next link after prev_link from v to w. If prev_link is |
334 | * NULL, return the first link from v to w. Ignore stub and virtual links; | |
335 | * these link types will never be returned. | |
336 | */ | |
4dadc291 | 337 | static struct router_lsa_link * |
718e3744 | 338 | ospf_get_next_link (struct vertex *v, struct vertex *w, |
0c0f9cd5 | 339 | struct router_lsa_link *prev_link) |
718e3744 | 340 | { |
341 | u_char *p; | |
342 | u_char *lim; | |
343 | struct router_lsa_link *l; | |
344 | ||
345 | if (prev_link == NULL) | |
630e4807 | 346 | p = ((u_char *) v->lsa) + OSPF_LSA_HEADER_SIZE + 4; |
718e3744 | 347 | else |
348 | { | |
0c0f9cd5 | 349 | p = (u_char *) prev_link; |
718e3744 | 350 | p += (ROUTER_LSA_MIN_SIZE + |
351 | (prev_link->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); | |
352 | } | |
0c0f9cd5 | 353 | |
718e3744 | 354 | lim = ((u_char *) v->lsa) + ntohs (v->lsa->length); |
355 | ||
356 | while (p < lim) | |
357 | { | |
358 | l = (struct router_lsa_link *) p; | |
359 | ||
0c0f9cd5 | 360 | p += (ROUTER_LSA_MIN_SIZE + (l->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); |
718e3744 | 361 | |
362 | if (l->m[0].type == LSA_LINK_TYPE_STUB) | |
363 | continue; | |
364 | ||
365 | /* Defer NH calculation via VLs until summaries from | |
366 | transit areas area confidered */ | |
367 | ||
368 | if (l->m[0].type == LSA_LINK_TYPE_VIRTUALLINK) | |
0c0f9cd5 | 369 | continue; |
718e3744 | 370 | |
371 | if (IPV4_ADDR_SAME (&l->link_id, &w->id)) | |
0c0f9cd5 | 372 | return l; |
718e3744 | 373 | } |
374 | ||
375 | return NULL; | |
376 | } | |
377 | ||
75ee0b8e | 378 | /* |
379 | * Consider supplied next-hop for inclusion to the supplied list of | |
380 | * equal-cost next-hops, adjust list as neccessary. | |
381 | * | |
382 | * (Discussed on GNU Zebra list 27 May 2003, [zebra 19184]) | |
383 | * | |
384 | * Note that below is a bit of a hack, and limits ECMP to paths that go to | |
385 | * same nexthop. Where as paths via inequal output_cost interfaces could | |
386 | * still quite easily be ECMP due to remote cost differences. | |
387 | * | |
388 | * TODO: It really should be done by way of recording currently valid | |
389 | * backlinks and determining the appropriate nexthops from the list of | |
390 | * backlinks, or even simpler, just flushing nexthop list if we find a lower | |
391 | * cost path to a candidate vertex in SPF, maybe. | |
bf9392c6 | 392 | */ |
4dadc291 | 393 | static void |
0c0f9cd5 | 394 | ospf_spf_consider_nexthop (struct list *nexthops, |
395 | struct vertex_nexthop *newhop) | |
bf9392c6 | 396 | { |
bf9392c6 | 397 | struct vertex_nexthop *hop; |
75ee0b8e | 398 | struct listnode *ln, *nn; |
0c0f9cd5 | 399 | |
75ee0b8e | 400 | /* nexthop list should contain only the set of nexthops that have the lowest |
401 | * equal cost | |
402 | */ | |
403 | if (nexthops->head != NULL) | |
404 | { | |
1eb8ef25 | 405 | hop = listgetdata (nexthops->head); |
75ee0b8e | 406 | |
407 | /* weed out hops with higher cost than the newhop */ | |
408 | if (hop->oi->output_cost > newhop->oi->output_cost) | |
409 | { | |
410 | /* delete the existing nexthops */ | |
1eb8ef25 | 411 | for (ALL_LIST_ELEMENTS (nexthops, ln, nn, hop)) |
75ee0b8e | 412 | { |
75ee0b8e | 413 | listnode_delete (nexthops, hop); |
414 | vertex_nexthop_free (hop); | |
415 | } | |
416 | } | |
417 | else if (hop->oi->output_cost < newhop->oi->output_cost) | |
0c0f9cd5 | 418 | return; |
75ee0b8e | 419 | } |
0c0f9cd5 | 420 | |
bf9392c6 | 421 | /* new hop is <= existing hops, add it */ |
0c0f9cd5 | 422 | listnode_add (nexthops, newhop); |
bf9392c6 | 423 | |
424 | return; | |
425 | } | |
426 | ||
630e4807 | 427 | /* 16.1.1. Calculate nexthop from root through V (parent) to |
428 | * vertex W (destination). | |
429 | */ | |
4dadc291 | 430 | static void |
718e3744 | 431 | ospf_nexthop_calculation (struct ospf_area *area, |
432 | struct vertex *v, struct vertex *w) | |
433 | { | |
1eb8ef25 | 434 | struct listnode *node, *nnode; |
718e3744 | 435 | struct vertex_nexthop *nh, *x; |
436 | struct ospf_interface *oi = NULL; | |
437 | struct router_lsa_link *l = NULL; | |
0c0f9cd5 | 438 | |
439 | ||
718e3744 | 440 | if (IS_DEBUG_OSPF_EVENT) |
630e4807 | 441 | { |
2a42e285 | 442 | zlog_debug ("ospf_nexthop_calculation(): Start"); |
630e4807 | 443 | ospf_vertex_dump("V (parent):", v, 1, 1); |
444 | ospf_vertex_dump("W (dest) :", w, 1, 1); | |
445 | } | |
718e3744 | 446 | |
718e3744 | 447 | if (v == area->spf) |
448 | { | |
630e4807 | 449 | /* 16.1.1 para 4. In the first case, the parent vertex (V) is the |
450 | root (the calculating router itself). This means that the | |
451 | destination is either a directly connected network or directly | |
452 | connected router. The outgoing interface in this case is simply | |
453 | the OSPF interface connecting to the destination network/router. | |
454 | */ | |
455 | ||
718e3744 | 456 | if (w->type == OSPF_VERTEX_ROUTER) |
0c0f9cd5 | 457 | { |
458 | while ((l = ospf_get_next_link (v, w, l))) | |
459 | { | |
630e4807 | 460 | /* l is a link from v to w |
461 | * l2 will be link from w to v | |
462 | */ | |
0c0f9cd5 | 463 | struct router_lsa_link *l2 = NULL; |
464 | ||
630e4807 | 465 | if (IS_DEBUG_OSPF_EVENT) |
466 | { | |
467 | char buf1[BUFSIZ]; | |
1eb8ef25 | 468 | char buf2[BUFSIZ]; |
469 | ||
2a42e285 | 470 | zlog_debug("ospf_nexthop_calculation(): considering link " |
630e4807 | 471 | "type %d link_id %s link_data %s", |
472 | l->m[0].type, | |
473 | inet_ntop (AF_INET, &l->link_id, buf1, BUFSIZ), | |
1eb8ef25 | 474 | inet_ntop (AF_INET, &l->link_data, buf2, BUFSIZ)); |
630e4807 | 475 | } |
476 | ||
0c0f9cd5 | 477 | if (l->m[0].type == LSA_LINK_TYPE_POINTOPOINT) |
478 | { | |
630e4807 | 479 | /* If the destination is a router which connects to |
480 | the calculating router via a Point-to-MultiPoint | |
481 | network, the destination's next hop IP address(es) | |
482 | can be determined by examining the destination's | |
483 | router-LSA: each link pointing back to the | |
484 | calculating router and having a Link Data field | |
485 | belonging to the Point-to-MultiPoint network | |
486 | provides an IP address of the next hop router. | |
487 | ||
488 | At this point l is a link from V to W, and V is the | |
489 | root ("us"). Find the local interface associated | |
490 | with l (its address is in l->link_data). If it | |
491 | is a point-to-multipoint interface, then look through | |
492 | the links in the opposite direction (W to V). If | |
493 | any of them have an address that lands within the | |
494 | subnet declared by the PtMP link, then that link | |
495 | is a constituent of the PtMP link, and its address is | |
496 | a nexthop address for V. | |
497 | */ | |
68980084 | 498 | oi = ospf_if_is_configured (area->ospf, &l->link_data); |
7afa08da | 499 | if (oi && oi->type == OSPF_IFTYPE_POINTOMULTIPOINT) |
0c0f9cd5 | 500 | { |
501 | struct prefix_ipv4 la; | |
630e4807 | 502 | |
503 | la.family = AF_INET; | |
0c0f9cd5 | 504 | la.prefixlen = oi->address->prefixlen; |
630e4807 | 505 | |
506 | /* V links to W on PtMP interface | |
507 | - find the interface address on W */ | |
0c0f9cd5 | 508 | while ((l2 = ospf_get_next_link (w, v, l2))) |
509 | { | |
510 | la.prefix = l2->link_data; | |
511 | ||
512 | if (prefix_cmp ((struct prefix *) &la, | |
513 | oi->address) == 0) | |
514 | /* link_data is on our PtMP network */ | |
515 | break; | |
516 | } | |
630e4807 | 517 | } /* end l is on point-to-multipoint link */ |
0c0f9cd5 | 518 | else |
519 | { | |
630e4807 | 520 | /* l is a regular point-to-point link. |
521 | Look for a link from W to V. | |
522 | */ | |
0c0f9cd5 | 523 | while ((l2 = ospf_get_next_link (w, v, l2))) |
524 | { | |
525 | oi = ospf_if_is_configured (area->ospf, | |
526 | &(l2->link_data)); | |
527 | ||
528 | if (oi == NULL) | |
529 | continue; | |
530 | ||
531 | if (!IPV4_ADDR_SAME (&oi->address->u.prefix4, | |
532 | &l->link_data)) | |
533 | continue; | |
534 | ||
535 | break; | |
536 | } | |
537 | } | |
538 | ||
539 | if (oi && l2) | |
540 | { | |
630e4807 | 541 | /* found all necessary info to build nexthop */ |
0c0f9cd5 | 542 | nh = vertex_nexthop_new (v); |
543 | nh->oi = oi; | |
544 | nh->router = l2->link_data; | |
545 | ospf_spf_consider_nexthop (w->nexthop, nh); | |
546 | } | |
630e4807 | 547 | else |
548 | { | |
549 | zlog_info("ospf_nexthop_calculation(): " | |
550 | "could not determine nexthop for link"); | |
551 | } | |
552 | } /* end point-to-point link from V to W */ | |
553 | } /* end iterate over links in W */ | |
554 | } /* end W is a Router vertex */ | |
718e3744 | 555 | else |
0c0f9cd5 | 556 | { |
630e4807 | 557 | assert(w->type == OSPF_VERTEX_NETWORK); |
0c0f9cd5 | 558 | while ((l = ospf_get_next_link (v, w, l))) |
559 | { | |
560 | oi = ospf_if_is_configured (area->ospf, &(l->link_data)); | |
561 | if (oi) | |
562 | { | |
563 | nh = vertex_nexthop_new (v); | |
564 | nh->oi = oi; | |
565 | nh->router.s_addr = 0; | |
75ee0b8e | 566 | ospf_spf_consider_nexthop (w->nexthop, nh); |
0c0f9cd5 | 567 | } |
568 | } | |
569 | } | |
718e3744 | 570 | return; |
630e4807 | 571 | } /* end V is the root */ |
572 | ||
573 | /* Check if W's parent is a network connected to root. */ | |
718e3744 | 574 | else if (v->type == OSPF_VERTEX_NETWORK) |
575 | { | |
630e4807 | 576 | /* See if any of V's parents are the root. */ |
1eb8ef25 | 577 | for (ALL_LIST_ELEMENTS (v->nexthop, node, nnode, x)) |
718e3744 | 578 | { |
630e4807 | 579 | if (x->parent == area->spf) /* connects to root? */ |
580 | { | |
581 | /* 16.1.1 para 5. ...the parent vertex is a network that | |
582 | * directly connects the calculating router to the destination | |
583 | * router. The list of next hops is then determined by | |
584 | * examining the destination's router-LSA... | |
585 | */ | |
586 | ||
587 | assert(w->type == OSPF_VERTEX_ROUTER); | |
0c0f9cd5 | 588 | while ((l = ospf_get_next_link (w, v, l))) |
589 | { | |
630e4807 | 590 | /* ...For each link in the router-LSA that points back to the |
591 | * parent network, the link's Link Data field provides the IP | |
592 | * address of a next hop router. The outgoing interface to | |
593 | * use can then be derived from the next hop IP address (or | |
594 | * it can be inherited from the parent network). | |
595 | */ | |
0c0f9cd5 | 596 | nh = vertex_nexthop_new (v); |
597 | nh->oi = x->oi; | |
598 | nh->router = l->link_data; | |
75ee0b8e | 599 | ospf_spf_consider_nexthop (w->nexthop, nh); |
0c0f9cd5 | 600 | } |
601 | return; | |
602 | } | |
718e3744 | 603 | } |
604 | } | |
605 | ||
630e4807 | 606 | /* 16.1.1 para 4. If there is at least one intervening router in the |
607 | * current shortest path between the destination and the root, the | |
608 | * destination simply inherits the set of next hops from the | |
609 | * parent. | |
610 | */ | |
1eb8ef25 | 611 | for (ALL_LIST_ELEMENTS (v->nexthop, node, nnode, nh)) |
718e3744 | 612 | { |
718e3744 | 613 | nh->parent = v; |
614 | ospf_nexthop_add_unique (nh, w->nexthop); | |
615 | } | |
616 | } | |
617 | ||
630e4807 | 618 | /* RFC2328 Section 16.1 (2). |
619 | * v is on the SPF tree. Examine the links in v's LSA. Update the list | |
620 | * of candidates with any vertices not already on the list. If a lower-cost | |
621 | * path is found to a vertex already on the candidate list, store the new cost. | |
622 | */ | |
4dadc291 | 623 | static void |
718e3744 | 624 | ospf_spf_next (struct vertex *v, struct ospf_area *area, |
462f20d5 | 625 | struct pqueue * candidate) |
718e3744 | 626 | { |
627 | struct ospf_lsa *w_lsa = NULL; | |
628 | struct vertex *w, *cw; | |
629 | u_char *p; | |
630 | u_char *lim; | |
631 | struct router_lsa_link *l = NULL; | |
632 | struct in_addr *r; | |
718e3744 | 633 | int type = 0; |
634 | ||
635 | /* If this is a router-LSA, and bit V of the router-LSA (see Section | |
636 | A.4.2:RFC2328) is set, set Area A's TransitCapability to TRUE. */ | |
637 | if (v->type == OSPF_VERTEX_ROUTER) | |
638 | { | |
639 | if (IS_ROUTER_LSA_VIRTUAL ((struct router_lsa *) v->lsa)) | |
640 | area->transit = OSPF_TRANSIT_TRUE; | |
641 | } | |
642 | ||
643 | p = ((u_char *) v->lsa) + OSPF_LSA_HEADER_SIZE + 4; | |
0c0f9cd5 | 644 | lim = ((u_char *) v->lsa) + ntohs (v->lsa->length); |
645 | ||
718e3744 | 646 | while (p < lim) |
647 | { | |
d355bfa7 | 648 | int link = -1; /* link index for w's back link */ |
649 | ||
718e3744 | 650 | /* In case of V is Router-LSA. */ |
651 | if (v->lsa->type == OSPF_ROUTER_LSA) | |
652 | { | |
653 | l = (struct router_lsa_link *) p; | |
654 | ||
0c0f9cd5 | 655 | p += (ROUTER_LSA_MIN_SIZE + |
718e3744 | 656 | (l->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); |
657 | ||
658 | /* (a) If this is a link to a stub network, examine the next | |
659 | link in V's LSA. Links to stub networks will be | |
660 | considered in the second stage of the shortest path | |
661 | calculation. */ | |
662 | if ((type = l->m[0].type) == LSA_LINK_TYPE_STUB) | |
663 | continue; | |
664 | ||
665 | /* (b) Otherwise, W is a transit vertex (router or transit | |
666 | network). Look up the vertex W's LSA (router-LSA or | |
667 | network-LSA) in Area A's link state database. */ | |
668 | switch (type) | |
669 | { | |
670 | case LSA_LINK_TYPE_POINTOPOINT: | |
671 | case LSA_LINK_TYPE_VIRTUALLINK: | |
672 | if (type == LSA_LINK_TYPE_VIRTUALLINK) | |
0c0f9cd5 | 673 | { |
674 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 675 | zlog_debug ("looking up LSA through VL: %s", |
0c0f9cd5 | 676 | inet_ntoa (l->link_id)); |
677 | } | |
718e3744 | 678 | |
679 | w_lsa = ospf_lsa_lookup (area, OSPF_ROUTER_LSA, l->link_id, | |
680 | l->link_id); | |
681 | if (w_lsa) | |
0c0f9cd5 | 682 | { |
683 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 684 | zlog_debug ("found Router LSA %s", inet_ntoa (l->link_id)); |
0c0f9cd5 | 685 | } |
718e3744 | 686 | break; |
687 | case LSA_LINK_TYPE_TRANSIT: | |
0c0f9cd5 | 688 | if (IS_DEBUG_OSPF_EVENT) |
2a42e285 | 689 | zlog_debug ("Looking up Network LSA, ID: %s", |
0c0f9cd5 | 690 | inet_ntoa (l->link_id)); |
718e3744 | 691 | w_lsa = ospf_lsa_lookup_by_id (area, OSPF_NETWORK_LSA, |
0c0f9cd5 | 692 | l->link_id); |
718e3744 | 693 | if (w_lsa) |
0c0f9cd5 | 694 | if (IS_DEBUG_OSPF_EVENT) |
2a42e285 | 695 | zlog_debug ("found the LSA"); |
718e3744 | 696 | break; |
697 | default: | |
0c0f9cd5 | 698 | zlog_warn ("Invalid LSA link type %d", type); |
718e3744 | 699 | continue; |
700 | } | |
701 | } | |
702 | else | |
703 | { | |
704 | /* In case of V is Network-LSA. */ | |
0c0f9cd5 | 705 | r = (struct in_addr *) p; |
718e3744 | 706 | p += sizeof (struct in_addr); |
707 | ||
708 | /* Lookup the vertex W's LSA. */ | |
709 | w_lsa = ospf_lsa_lookup_by_id (area, OSPF_ROUTER_LSA, *r); | |
710 | } | |
711 | ||
712 | /* (b cont.) If the LSA does not exist, or its LS age is equal | |
713 | to MaxAge, or it does not have a link back to vertex V, | |
714 | examine the next link in V's LSA.[23] */ | |
715 | if (w_lsa == NULL) | |
716 | continue; | |
717 | ||
718 | if (IS_LSA_MAXAGE (w_lsa)) | |
719 | continue; | |
720 | ||
d355bfa7 | 721 | if ( (link = ospf_lsa_has_link (w_lsa->data, v->lsa)) < 0 ) |
718e3744 | 722 | { |
0c0f9cd5 | 723 | if (IS_DEBUG_OSPF_EVENT) |
2a42e285 | 724 | zlog_debug ("The LSA doesn't have a link back"); |
718e3744 | 725 | continue; |
726 | } | |
727 | ||
728 | /* (c) If vertex W is already on the shortest-path tree, examine | |
729 | the next link in the LSA. */ | |
462f20d5 | 730 | if (w_lsa->stat == LSA_SPF_IN_SPFTREE) |
731 | { | |
732 | if (IS_DEBUG_OSPF_EVENT) | |
733 | zlog_debug ("The LSA is already in SPF"); | |
734 | continue; | |
735 | } | |
718e3744 | 736 | |
737 | /* (d) Calculate the link state cost D of the resulting path | |
738 | from the root to vertex W. D is equal to the sum of the link | |
739 | state cost of the (already calculated) shortest path to | |
740 | vertex V and the advertised cost of the link between vertices | |
741 | V and W. If D is: */ | |
742 | ||
743 | /* prepare vertex W. */ | |
744 | w = ospf_vertex_new (w_lsa); | |
745 | ||
d355bfa7 | 746 | /* Save W's back link index number, for use by virtual links */ |
747 | w->backlink = link; | |
748 | ||
718e3744 | 749 | /* calculate link cost D. */ |
750 | if (v->lsa->type == OSPF_ROUTER_LSA) | |
630e4807 | 751 | w->distance = v->distance + ntohs (l->m[0].metric); |
752 | else /* v is not a Router-LSA */ | |
753 | w->distance = v->distance; | |
718e3744 | 754 | |
755 | /* Is there already vertex W in candidate list? */ | |
462f20d5 | 756 | if (w_lsa->stat == LSA_SPF_NOT_EXPLORED) |
757 | { | |
758 | /* Calculate nexthop to W. */ | |
759 | ospf_nexthop_calculation (area, v, w); | |
760 | pqueue_enqueue (w, candidate); | |
761 | } | |
762 | else if (w_lsa->stat >= 0) | |
763 | { | |
764 | /* Get the vertex from candidates. */ | |
765 | cw = (struct vertex *) candidate->array[w_lsa->stat]; | |
718e3744 | 766 | |
462f20d5 | 767 | /* if D is greater than. */ |
768 | if (cw->distance < w->distance) | |
718e3744 | 769 | { |
770 | ospf_vertex_free (w); | |
771 | continue; | |
772 | } | |
462f20d5 | 773 | /* equal to. */ |
774 | else if (cw->distance == w->distance) | |
718e3744 | 775 | { |
630e4807 | 776 | /* Found an equal-cost path to W. Calculate nexthop to W. */ |
718e3744 | 777 | ospf_nexthop_calculation (area, v, w); |
778 | ospf_nexthop_merge (cw->nexthop, w->nexthop); | |
779 | list_delete_all_node (w->nexthop); | |
780 | ospf_vertex_free (w); | |
781 | } | |
462f20d5 | 782 | /* less than. */ |
783 | else | |
718e3744 | 784 | { |
630e4807 | 785 | /* Found a lower-cost path to W. Calculate nexthop to W. */ |
718e3744 | 786 | ospf_nexthop_calculation (area, v, w); |
787 | ||
788 | /* Remove old vertex from candidate list. */ | |
789 | ospf_vertex_free (cw); | |
462f20d5 | 790 | candidate->array[w_lsa->stat] = w; |
791 | /* Decrease the key of the node in the heap, re-sort the heap. */ | |
792 | trickle_down (w_lsa->stat, candidate); | |
718e3744 | 793 | } |
630e4807 | 794 | } /* end W is already on the candidate list */ |
795 | } /* end loop over the links in V's LSA */ | |
718e3744 | 796 | } |
797 | ||
4dadc291 | 798 | static void |
718e3744 | 799 | ospf_spf_route_free (struct route_table *table) |
800 | { | |
801 | struct route_node *rn; | |
802 | struct vertex *v; | |
803 | ||
804 | for (rn = route_top (table); rn; rn = route_next (rn)) | |
805 | { | |
806 | if ((v = rn->info)) | |
0c0f9cd5 | 807 | { |
808 | ospf_vertex_free (v); | |
809 | rn->info = NULL; | |
810 | } | |
718e3744 | 811 | |
812 | route_unlock_node (rn); | |
813 | } | |
814 | ||
815 | route_table_finish (table); | |
816 | } | |
817 | ||
4dadc291 | 818 | static void |
718e3744 | 819 | ospf_spf_dump (struct vertex *v, int i) |
820 | { | |
52dc7ee6 | 821 | struct listnode *cnode; |
822 | struct listnode *nnode; | |
718e3744 | 823 | struct vertex_nexthop *nexthop; |
824 | ||
825 | if (v->type == OSPF_VERTEX_ROUTER) | |
826 | { | |
827 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 828 | zlog_debug ("SPF Result: %d [R] %s", i, inet_ntoa (v->lsa->id)); |
718e3744 | 829 | } |
830 | else | |
831 | { | |
832 | struct network_lsa *lsa = (struct network_lsa *) v->lsa; | |
833 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 834 | zlog_debug ("SPF Result: %d [N] %s/%d", i, inet_ntoa (v->lsa->id), |
0c0f9cd5 | 835 | ip_masklen (lsa->mask)); |
630e4807 | 836 | } |
718e3744 | 837 | |
1eb8ef25 | 838 | if (IS_DEBUG_OSPF_EVENT) |
839 | for (ALL_LIST_ELEMENTS_RO (v->nexthop, nnode, nexthop)) | |
840 | zlog_debug (" nexthop %s", inet_ntoa (nexthop->router)); | |
718e3744 | 841 | |
842 | i++; | |
843 | ||
1eb8ef25 | 844 | for (ALL_LIST_ELEMENTS_RO (v->child, cnode, v)) |
845 | ospf_spf_dump (v, i); | |
718e3744 | 846 | } |
847 | ||
848 | /* Second stage of SPF calculation. */ | |
4dadc291 | 849 | static void |
0c0f9cd5 | 850 | ospf_spf_process_stubs (struct ospf_area *area, struct vertex *v, |
718e3744 | 851 | struct route_table *rt) |
852 | { | |
1eb8ef25 | 853 | struct listnode *cnode, *cnnode; |
718e3744 | 854 | struct vertex *child; |
855 | ||
856 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 857 | zlog_debug ("ospf_process_stub():processing stubs for area %s", |
0c0f9cd5 | 858 | inet_ntoa (area->area_id)); |
718e3744 | 859 | if (v->type == OSPF_VERTEX_ROUTER) |
860 | { | |
861 | u_char *p; | |
862 | u_char *lim; | |
863 | struct router_lsa_link *l; | |
864 | struct router_lsa *rlsa; | |
865 | ||
0c0f9cd5 | 866 | if (IS_DEBUG_OSPF_EVENT) |
2a42e285 | 867 | zlog_debug ("ospf_process_stubs():processing router LSA, id: %s", |
0c0f9cd5 | 868 | inet_ntoa (v->lsa->id)); |
718e3744 | 869 | rlsa = (struct router_lsa *) v->lsa; |
870 | ||
871 | ||
0c0f9cd5 | 872 | if (IS_DEBUG_OSPF_EVENT) |
2a42e285 | 873 | zlog_debug ("ospf_process_stubs(): we have %d links to process", |
0c0f9cd5 | 874 | ntohs (rlsa->links)); |
630e4807 | 875 | p = ((u_char *) v->lsa) + OSPF_LSA_HEADER_SIZE + 4; |
718e3744 | 876 | lim = ((u_char *) v->lsa) + ntohs (v->lsa->length); |
877 | ||
878 | while (p < lim) | |
879 | { | |
880 | l = (struct router_lsa_link *) p; | |
881 | ||
882 | p += (ROUTER_LSA_MIN_SIZE + | |
883 | (l->m[0].tos_count * ROUTER_LSA_TOS_SIZE)); | |
884 | ||
885 | if (l->m[0].type == LSA_LINK_TYPE_STUB) | |
886 | ospf_intra_add_stub (rt, l, v, area); | |
887 | } | |
888 | } | |
889 | ||
630e4807 | 890 | ospf_vertex_dump("ospf_process_stubs(): after examining links: ", v, 1, 1); |
718e3744 | 891 | |
1eb8ef25 | 892 | for (ALL_LIST_ELEMENTS (v->child, cnode, cnnode, child)) |
718e3744 | 893 | { |
718e3744 | 894 | if (CHECK_FLAG (child->flags, OSPF_VERTEX_PROCESSED)) |
0c0f9cd5 | 895 | continue; |
718e3744 | 896 | |
897 | ospf_spf_process_stubs (area, child, rt); | |
898 | ||
899 | SET_FLAG (child->flags, OSPF_VERTEX_PROCESSED); | |
900 | } | |
901 | } | |
902 | ||
903 | void | |
904 | ospf_rtrs_free (struct route_table *rtrs) | |
905 | { | |
906 | struct route_node *rn; | |
52dc7ee6 | 907 | struct list *or_list; |
1eb8ef25 | 908 | struct ospf_route *or; |
909 | struct listnode *node, *nnode; | |
718e3744 | 910 | |
911 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 912 | zlog_debug ("Route: Router Routing Table free"); |
718e3744 | 913 | |
914 | for (rn = route_top (rtrs); rn; rn = route_next (rn)) | |
915 | if ((or_list = rn->info) != NULL) | |
916 | { | |
1eb8ef25 | 917 | for (ALL_LIST_ELEMENTS (or_list, node, nnode, or)) |
918 | ospf_route_free (or); | |
718e3744 | 919 | |
0c0f9cd5 | 920 | list_delete (or_list); |
718e3744 | 921 | |
0c0f9cd5 | 922 | /* Unlock the node. */ |
923 | rn->info = NULL; | |
924 | route_unlock_node (rn); | |
718e3744 | 925 | } |
926 | route_table_finish (rtrs); | |
927 | } | |
928 | ||
4dadc291 | 929 | static void |
718e3744 | 930 | ospf_rtrs_print (struct route_table *rtrs) |
931 | { | |
932 | struct route_node *rn; | |
52dc7ee6 | 933 | struct list *or_list; |
934 | struct listnode *ln; | |
935 | struct listnode *pnode; | |
718e3744 | 936 | struct ospf_route *or; |
937 | struct ospf_path *path; | |
938 | char buf1[BUFSIZ]; | |
939 | char buf2[BUFSIZ]; | |
940 | ||
941 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 942 | zlog_debug ("ospf_rtrs_print() start"); |
718e3744 | 943 | |
944 | for (rn = route_top (rtrs); rn; rn = route_next (rn)) | |
945 | if ((or_list = rn->info) != NULL) | |
1eb8ef25 | 946 | for (ALL_LIST_ELEMENTS_RO (or_list, ln, or)) |
718e3744 | 947 | { |
718e3744 | 948 | switch (or->path_type) |
949 | { | |
950 | case OSPF_PATH_INTRA_AREA: | |
0c0f9cd5 | 951 | if (IS_DEBUG_OSPF_EVENT) |
2a42e285 | 952 | zlog_debug ("%s [%d] area: %s", |
0c0f9cd5 | 953 | inet_ntop (AF_INET, &or->id, buf1, BUFSIZ), |
954 | or->cost, inet_ntop (AF_INET, &or->u.std.area_id, | |
955 | buf2, BUFSIZ)); | |
718e3744 | 956 | break; |
957 | case OSPF_PATH_INTER_AREA: | |
0c0f9cd5 | 958 | if (IS_DEBUG_OSPF_EVENT) |
2a42e285 | 959 | zlog_debug ("%s IA [%d] area: %s", |
0c0f9cd5 | 960 | inet_ntop (AF_INET, &or->id, buf1, BUFSIZ), |
961 | or->cost, inet_ntop (AF_INET, &or->u.std.area_id, | |
962 | buf2, BUFSIZ)); | |
718e3744 | 963 | break; |
964 | default: | |
965 | break; | |
966 | } | |
967 | ||
1eb8ef25 | 968 | for (ALL_LIST_ELEMENTS_RO (or->paths, pnode, path)) |
718e3744 | 969 | { |
718e3744 | 970 | if (path->nexthop.s_addr == 0) |
0c0f9cd5 | 971 | { |
972 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 973 | zlog_debug (" directly attached to %s\r\n", |
0c0f9cd5 | 974 | IF_NAME (path->oi)); |
975 | } | |
976 | else | |
977 | { | |
978 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 979 | zlog_debug (" via %s, %s\r\n", |
0c0f9cd5 | 980 | inet_ntoa (path->nexthop), IF_NAME (path->oi)); |
981 | } | |
718e3744 | 982 | } |
983 | } | |
984 | ||
2a42e285 | 985 | zlog_debug ("ospf_rtrs_print() end"); |
718e3744 | 986 | } |
987 | ||
988 | /* Calculating the shortest-path tree for an area. */ | |
4dadc291 | 989 | static void |
0c0f9cd5 | 990 | ospf_spf_calculate (struct ospf_area *area, struct route_table *new_table, |
718e3744 | 991 | struct route_table *new_rtrs) |
992 | { | |
462f20d5 | 993 | struct pqueue *candidate; |
718e3744 | 994 | struct vertex *v; |
718e3744 | 995 | |
996 | if (IS_DEBUG_OSPF_EVENT) | |
997 | { | |
2a42e285 | 998 | zlog_debug ("ospf_spf_calculate: Start"); |
999 | zlog_debug ("ospf_spf_calculate: running Dijkstra for area %s", | |
0c0f9cd5 | 1000 | inet_ntoa (area->area_id)); |
718e3744 | 1001 | } |
1002 | ||
1003 | /* Check router-lsa-self. If self-router-lsa is not yet allocated, | |
1004 | return this area's calculation. */ | |
0c0f9cd5 | 1005 | if (!area->router_lsa_self) |
718e3744 | 1006 | { |
1007 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 1008 | zlog_debug ("ospf_spf_calculate: " |
0c0f9cd5 | 1009 | "Skip area %s's calculation due to empty router_lsa_self", |
1010 | inet_ntoa (area->area_id)); | |
718e3744 | 1011 | return; |
1012 | } | |
1013 | ||
1014 | /* RFC2328 16.1. (1). */ | |
0c0f9cd5 | 1015 | /* Initialize the algorithm's data structures. */ |
462f20d5 | 1016 | |
1017 | /* This function scans all the LSA database and set the stat field to | |
1018 | * LSA_SPF_NOT_EXPLORED. */ | |
1019 | ospf_lsdb_clean_stat (area->lsdb); | |
1020 | /* Create a new heap for the candidates. */ | |
1021 | candidate = pqueue_create(); | |
1022 | candidate->cmp = cmp; | |
1023 | candidate->update = update_stat; | |
718e3744 | 1024 | |
1025 | /* Initialize the shortest-path tree to only the root (which is the | |
1026 | router doing the calculation). */ | |
1027 | ospf_spf_init (area); | |
1028 | v = area->spf; | |
462f20d5 | 1029 | /* Set LSA position to LSA_SPF_IN_SPFTREE. This vertex is the root of the |
1030 | * spanning tree. */ | |
1031 | *(v->stat) = LSA_SPF_IN_SPFTREE; | |
718e3744 | 1032 | |
1033 | /* Set Area A's TransitCapability to FALSE. */ | |
1034 | area->transit = OSPF_TRANSIT_FALSE; | |
1035 | area->shortcut_capability = 1; | |
1036 | ||
1037 | for (;;) | |
1038 | { | |
1039 | /* RFC2328 16.1. (2). */ | |
462f20d5 | 1040 | ospf_spf_next (v, area, candidate); |
718e3744 | 1041 | |
1042 | /* RFC2328 16.1. (3). */ | |
1043 | /* If at this step the candidate list is empty, the shortest- | |
1044 | path tree (of transit vertices) has been completely built and | |
1045 | this stage of the procedure terminates. */ | |
462f20d5 | 1046 | if (candidate->size == 0) |
718e3744 | 1047 | break; |
1048 | ||
1049 | /* Otherwise, choose the vertex belonging to the candidate list | |
1050 | that is closest to the root, and add it to the shortest-path | |
1051 | tree (removing it from the candidate list in the | |
0c0f9cd5 | 1052 | process). */ |
462f20d5 | 1053 | /* Extract from the candidates the node with the lower key. */ |
1054 | v = (struct vertex *) pqueue_dequeue (candidate); | |
1055 | /* Update stat field in vertex. */ | |
1056 | *(v->stat) = LSA_SPF_IN_SPFTREE; | |
718e3744 | 1057 | ospf_vertex_add_parent (v); |
1058 | ||
718e3744 | 1059 | /* Note that when there is a choice of vertices closest to the |
1060 | root, network vertices must be chosen before router vertices | |
1061 | in order to necessarily find all equal-cost paths. */ | |
1062 | /* We don't do this at this moment, we should add the treatment | |
1063 | above codes. -- kunihiro. */ | |
1064 | ||
1065 | /* RFC2328 16.1. (4). */ | |
1066 | if (v->type == OSPF_VERTEX_ROUTER) | |
1067 | ospf_intra_add_router (new_rtrs, v, area); | |
0c0f9cd5 | 1068 | else |
718e3744 | 1069 | ospf_intra_add_transit (new_table, v, area); |
1070 | ||
1071 | /* RFC2328 16.1. (5). */ | |
1072 | /* Iterate the algorithm by returning to Step 2. */ | |
630e4807 | 1073 | |
1074 | } /* end loop until no more candidate vertices */ | |
718e3744 | 1075 | |
1076 | if (IS_DEBUG_OSPF_EVENT) | |
1077 | { | |
1078 | ospf_spf_dump (area->spf, 0); | |
1079 | ospf_route_table_dump (new_table); | |
1080 | } | |
1081 | ||
1082 | /* Second stage of SPF calculation procedure's */ | |
1083 | ospf_spf_process_stubs (area, area->spf, new_table); | |
1084 | ||
462f20d5 | 1085 | /* Free candidates. */ |
1086 | pqueue_delete (candidate); | |
718e3744 | 1087 | |
1088 | /* Increment SPF Calculation Counter. */ | |
1089 | area->spf_calculation++; | |
1090 | ||
68980084 | 1091 | area->ospf->ts_spf = time (NULL); |
718e3744 | 1092 | |
1093 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 1094 | zlog_debug ("ospf_spf_calculate: Stop"); |
718e3744 | 1095 | } |
1096 | \f | |
1097 | /* Timer for SPF calculation. */ | |
4dadc291 | 1098 | static int |
68980084 | 1099 | ospf_spf_calculate_timer (struct thread *thread) |
718e3744 | 1100 | { |
68980084 | 1101 | struct ospf *ospf = THREAD_ARG (thread); |
718e3744 | 1102 | struct route_table *new_table, *new_rtrs; |
1eb8ef25 | 1103 | struct ospf_area *area; |
1104 | struct listnode *node, *nnode; | |
718e3744 | 1105 | |
1106 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 1107 | zlog_debug ("SPF: Timer (SPF calculation expire)"); |
0c0f9cd5 | 1108 | |
718e3744 | 1109 | ospf->t_spf_calc = NULL; |
1110 | ||
1111 | /* Allocate new table tree. */ | |
1112 | new_table = route_table_init (); | |
0c0f9cd5 | 1113 | new_rtrs = route_table_init (); |
718e3744 | 1114 | |
68980084 | 1115 | ospf_vl_unapprove (ospf); |
718e3744 | 1116 | |
1117 | /* Calculate SPF for each area. */ | |
1eb8ef25 | 1118 | for (ALL_LIST_ELEMENTS (ospf->areas, node, nnode, area)) |
1119 | ospf_spf_calculate (area, new_table, new_rtrs); | |
718e3744 | 1120 | |
68980084 | 1121 | ospf_vl_shut_unapproved (ospf); |
718e3744 | 1122 | |
68980084 | 1123 | ospf_ia_routing (ospf, new_table, new_rtrs); |
718e3744 | 1124 | |
1125 | ospf_prune_unreachable_networks (new_table); | |
1126 | ospf_prune_unreachable_routers (new_rtrs); | |
1127 | ||
1128 | /* AS-external-LSA calculation should not be performed here. */ | |
1129 | ||
1130 | /* If new Router Route is installed, | |
1131 | then schedule re-calculate External routes. */ | |
1132 | if (1) | |
68980084 | 1133 | ospf_ase_calculate_schedule (ospf); |
718e3744 | 1134 | |
68980084 | 1135 | ospf_ase_calculate_timer_add (ospf); |
718e3744 | 1136 | |
1137 | /* Update routing table. */ | |
68980084 | 1138 | ospf_route_install (ospf, new_table); |
718e3744 | 1139 | |
1140 | /* Update ABR/ASBR routing table */ | |
68980084 | 1141 | if (ospf->old_rtrs) |
718e3744 | 1142 | { |
1143 | /* old_rtrs's node holds linked list of ospf_route. --kunihiro. */ | |
68980084 | 1144 | /* ospf_route_delete (ospf->old_rtrs); */ |
1145 | ospf_rtrs_free (ospf->old_rtrs); | |
718e3744 | 1146 | } |
1147 | ||
68980084 | 1148 | ospf->old_rtrs = ospf->new_rtrs; |
1149 | ospf->new_rtrs = new_rtrs; | |
718e3744 | 1150 | |
0c0f9cd5 | 1151 | if (IS_OSPF_ABR (ospf)) |
68980084 | 1152 | ospf_abr_task (ospf); |
718e3744 | 1153 | |
1154 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 1155 | zlog_debug ("SPF: calculation complete"); |
718e3744 | 1156 | |
1157 | return 0; | |
1158 | } | |
1159 | ||
1160 | /* Add schedule for SPF calculation. To avoid frequenst SPF calc, we | |
1161 | set timer for SPF calc. */ | |
1162 | void | |
68980084 | 1163 | ospf_spf_calculate_schedule (struct ospf *ospf) |
718e3744 | 1164 | { |
1165 | time_t ht, delay; | |
1166 | ||
1167 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 1168 | zlog_debug ("SPF: calculation timer scheduled"); |
718e3744 | 1169 | |
1170 | /* OSPF instance does not exist. */ | |
68980084 | 1171 | if (ospf == NULL) |
718e3744 | 1172 | return; |
1173 | ||
1174 | /* SPF calculation timer is already scheduled. */ | |
68980084 | 1175 | if (ospf->t_spf_calc) |
718e3744 | 1176 | { |
1177 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 1178 | zlog_debug ("SPF: calculation timer is already scheduled: %p", |
0c0f9cd5 | 1179 | ospf->t_spf_calc); |
718e3744 | 1180 | return; |
1181 | } | |
1182 | ||
68980084 | 1183 | ht = time (NULL) - ospf->ts_spf; |
718e3744 | 1184 | |
1185 | /* Get SPF calculation delay time. */ | |
68980084 | 1186 | if (ht < ospf->spf_holdtime) |
718e3744 | 1187 | { |
68980084 | 1188 | if (ospf->spf_holdtime - ht < ospf->spf_delay) |
0c0f9cd5 | 1189 | delay = ospf->spf_delay; |
718e3744 | 1190 | else |
0c0f9cd5 | 1191 | delay = ospf->spf_holdtime - ht; |
718e3744 | 1192 | } |
1193 | else | |
68980084 | 1194 | delay = ospf->spf_delay; |
718e3744 | 1195 | |
1196 | if (IS_DEBUG_OSPF_EVENT) | |
2a42e285 | 1197 | zlog_debug ("SPF: calculation timer delay = %ld", (long)delay); |
68980084 | 1198 | ospf->t_spf_calc = |
1199 | thread_add_timer (master, ospf_spf_calculate_timer, ospf, delay); | |
718e3744 | 1200 | } |