1/*
2 * OSPF Neighbor functions.
3 * Copyright (C) 1999, 2000 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
8 * it under the terms of the GNU General Public License as published
9 * by the Free Software Foundation; either version 2, or (at your
10 * option) any 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
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
21 */
22
23#include <zebra.h>
24
25#include "linklist.h"
26#include "prefix.h"
27#include "memory.h"
28#include "command.h"
29#include "thread.h"
30#include "stream.h"
31#include "table.h"
32#include "log.h"
33
34#include "ospfd/ospfd.h"
35#include "ospfd/ospf_interface.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_packet.h"
42#include "ospfd/ospf_network.h"
43#include "ospfd/ospf_flood.h"
44#include "ospfd/ospf_dump.h"
45
46/* Fill in the the 'key' as appropriate to retrieve the entry for nbr
47 * from the ospf_interface's nbrs table. Indexed by interface address
48 * for all cases except Virtual-link interfaces, where neighbours are
49 * indexed by router-ID instead.
50 */
51static void
52ospf_nbr_key (struct ospf_interface *oi, struct ospf_neighbor *nbr,
53              struct prefix *key)
54{
55  key->family = AF_INET;
56  key->prefixlen = IPV4_MAX_BITLEN;
57
58  /* vlinks are indexed by router-id */
59  if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
60    key->u.prefix4 = nbr->router_id;
61  else
62    key->u.prefix4 = nbr->src;
63  return;
64}
65
66struct ospf_neighbor *
67ospf_nbr_new (struct ospf_interface *oi)
68{
69  struct ospf_neighbor *nbr;
70
71  /* Allcate new neighbor. */
72  nbr = XCALLOC (MTYPE_OSPF_NEIGHBOR, sizeof (struct ospf_neighbor));
73
74  /* Relate neighbor to the interface. */
75  nbr->oi = oi;
76
77  /* Set default values. */
78  nbr->state = NSM_Down;
79
80  /* Set inheritance values. */
81  nbr->v_inactivity = OSPF_IF_PARAM (oi, v_wait);
82  nbr->v_db_desc = OSPF_IF_PARAM (oi, retransmit_interval);
83  nbr->v_ls_req = OSPF_IF_PARAM (oi, retransmit_interval);
84  nbr->v_ls_upd = OSPF_IF_PARAM (oi, retransmit_interval);
85  nbr->priority = -1;
86
87  /* DD flags. */
88  nbr->dd_flags = OSPF_DD_FLAG_MS|OSPF_DD_FLAG_M|OSPF_DD_FLAG_I;
89
90  /* Last received and sent DD. */
91  nbr->last_send = NULL;
92
93  nbr->nbr_nbma = NULL;
94
95  ospf_lsdb_init (&nbr->db_sum);
96  ospf_lsdb_init (&nbr->ls_rxmt);
97  ospf_lsdb_init (&nbr->ls_req);
98
99  nbr->crypt_seqnum = 0;
100
101  return nbr;
102}
103
104void
105ospf_nbr_free (struct ospf_neighbor *nbr)
106{
107  /* Free DB summary list. */
108  if (ospf_db_summary_count (nbr))
109    ospf_db_summary_clear (nbr);
110    /* ospf_db_summary_delete_all (nbr); */
111
112  /* Free ls request list. */
113  if (ospf_ls_request_count (nbr))
114    ospf_ls_request_delete_all (nbr);
115
116  /* Free retransmit list. */
117  if (ospf_ls_retransmit_count (nbr))
118    ospf_ls_retransmit_clear (nbr);
119
120  /* Cleanup LSDBs. */
121  ospf_lsdb_cleanup (&nbr->db_sum);
122  ospf_lsdb_cleanup (&nbr->ls_req);
123  ospf_lsdb_cleanup (&nbr->ls_rxmt);
124
125  /* Clear last send packet. */
126  if (nbr->last_send)
127    ospf_packet_free (nbr->last_send);
128
129  if (nbr->nbr_nbma)
130    {
131      nbr->nbr_nbma->nbr = NULL;
132      nbr->nbr_nbma = NULL;
133    }
134
135  /* Cancel all timers. */
136  OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
137  OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
138  OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
139  OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
140
141  /* Cancel all events. *//* Thread lookup cost would be negligible. */
142  thread_cancel_event (master, nbr);
143
144  XFREE (MTYPE_OSPF_NEIGHBOR, nbr);
145}
146
147/* Delete specified OSPF neighbor from interface. */
148void
149ospf_nbr_delete (struct ospf_neighbor *nbr)
150{
151  struct ospf_interface *oi;
152  struct route_node *rn;
153  struct prefix p;
154
155  oi = nbr->oi;
156
157  /* get appropriate prefix 'key' */
158  ospf_nbr_key (oi, nbr, &p);
159
160  rn = route_node_lookup (oi->nbrs, &p);
161  if (rn)
162    {
163      /* If lookup for a NBR succeeds, the leaf route_node could
164       * only exist because there is (or was) a nbr there.
165       * If the nbr was deleted, the leaf route_node should have
166       * lost its last refcount too, and be deleted.
167       * Therefore a looked-up leaf route_node in nbrs table
168       * should never have NULL info.
169       */
170      assert (rn->info);
171
172      if (rn->info)
173	{
174	  rn->info = NULL;
175	  route_unlock_node (rn);
176	}
177      else
178	zlog_info ("Can't find neighbor %s in the interface %s",
179		   inet_ntoa (nbr->src), IF_NAME (oi));
180
181      route_unlock_node (rn);
182    }
183
184  /* Free ospf_neighbor structure. */
185  ospf_nbr_free (nbr);
186}
187
188/* Check myself is in the neighbor list. */
189int
190ospf_nbr_bidirectional (struct in_addr *router_id,
191			struct in_addr *neighbors, int size)
192{
193  int i;
194  int max;
195
196  max = size / sizeof (struct in_addr);
197
198  for (i = 0; i < max; i ++)
199    if (IPV4_ADDR_SAME (router_id, &neighbors[i]))
200      return 1;
201
202  return 0;
203}
204
205/* Add self to nbr list. */
206void
207ospf_nbr_add_self (struct ospf_interface *oi)
208{
209  struct prefix p;
210  struct route_node *rn;
211
212  /* Initial state */
213  oi->nbr_self->address = *oi->address;
214  oi->nbr_self->priority = OSPF_IF_PARAM (oi, priority);
215  oi->nbr_self->router_id = oi->ospf->router_id;
216  oi->nbr_self->src = oi->address->u.prefix4;
217  oi->nbr_self->state = NSM_TwoWay;
218
219  switch (oi->area->external_routing)
220    {
221      case OSPF_AREA_DEFAULT:
222        SET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
223        break;
224      case OSPF_AREA_STUB:
225        UNSET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
226        break;
227      case OSPF_AREA_NSSA:
228        UNSET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
229        SET_FLAG (oi->nbr_self->options, OSPF_OPTION_NP);
230        break;
231    }
232
233  /* Add nbr_self to nbrs table */
234  ospf_nbr_key (oi, oi->nbr_self, &p);
235
236  rn = route_node_get (oi->nbrs, &p);
237  if (rn->info)
238    {
239      /* There is already pseudo neighbor. */
240      assert (oi->nbr_self == rn->info);
241      route_unlock_node (rn);
242    }
243  else
244    rn->info = oi->nbr_self;
245}
246
247/* Get neighbor count by status.
248   Specify status = 0, get all neighbor other than myself. */
249int
250ospf_nbr_count (struct ospf_interface *oi, int state)
251{
252  struct ospf_neighbor *nbr;
253  struct route_node *rn;
254  int count = 0;
255
256  for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
257    if ((nbr = rn->info))
258      if (!IPV4_ADDR_SAME (&nbr->router_id, &oi->ospf->router_id))
259	if (state == 0 || nbr->state == state)
260	  count++;
261
262  return count;
263}
264
265#ifdef HAVE_OPAQUE_LSA
266int
267ospf_nbr_count_opaque_capable (struct ospf_interface *oi)
268{
269  struct ospf_neighbor *nbr;
270  struct route_node *rn;
271  int count = 0;
272
273  for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
274    if ((nbr = rn->info))
275      if (!IPV4_ADDR_SAME (&nbr->router_id, &oi->ospf->router_id))
276	if (nbr->state == NSM_Full)
277	  if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
278	    count++;
279
280  return count;
281}
282#endif /* HAVE_OPAQUE_LSA */
283
284/* lookup nbr by address - use this only if you know you must
285 * otherwise use the ospf_nbr_lookup() wrapper, which deals
286 * with virtual link neighbours
287 */
288struct ospf_neighbor *
289ospf_nbr_lookup_by_addr (struct route_table *nbrs,
290			 struct in_addr *addr)
291{
292  struct prefix p;
293  struct route_node *rn;
294  struct ospf_neighbor *nbr;
295
296  p.family = AF_INET;
297  p.prefixlen = IPV4_MAX_BITLEN;
298  p.u.prefix4 = *addr;
299
300  rn = route_node_lookup (nbrs, &p);
301  if (! rn)
302    return NULL;
303
304  /* See comment in ospf_nbr_delete */
305  assert (rn->info);
306
307  if (rn->info == NULL)
308    {
309      route_unlock_node (rn);
310      return NULL;
311    }
312
313  nbr = (struct ospf_neighbor *) rn->info;
314  route_unlock_node (rn);
315
316  return nbr;
317}
318
319struct ospf_neighbor *
320ospf_nbr_lookup_by_routerid (struct route_table *nbrs,
321			     struct in_addr *id)
322{
323  struct route_node *rn;
324  struct ospf_neighbor *nbr;
325
326  for (rn = route_top (nbrs); rn; rn = route_next (rn))
327    if ((nbr = rn->info) != NULL)
328      if (IPV4_ADDR_SAME (&nbr->router_id, id))
329	{
330	  route_unlock_node(rn);
331	  return nbr;
332	}
333
334  return NULL;
335}
336
337void
338ospf_renegotiate_optional_capabilities (struct ospf *top)
339{
340  struct listnode *node;
341  struct ospf_interface *oi;
342  struct route_table *nbrs;
343  struct route_node *rn;
344  struct ospf_neighbor *nbr;
345
346  /* At first, flush self-originated LSAs from routing domain. */
347  ospf_flush_self_originated_lsas_now (top);
348
349  /* Revert all neighbor status to ExStart. */
350  for (ALL_LIST_ELEMENTS_RO (top->oiflist, node, oi))
351    {
352      if ((nbrs = oi->nbrs) == NULL)
353        continue;
354
355      for (rn = route_top (nbrs); rn; rn = route_next (rn))
356        {
357          if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
358            continue;
359
360          if (nbr->state < NSM_ExStart)
361            continue;
362
363          if (IS_DEBUG_OSPF_EVENT)
364            zlog_debug ("Renegotiate optional capabilities with neighbor(%s)", inet_ntoa (nbr->router_id));
365
366          OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_SeqNumberMismatch);
367        }
368    }
369
370  return;
371}
372
373
374struct ospf_neighbor *
375ospf_nbr_lookup (struct ospf_interface *oi, struct ip *iph,
376                 struct ospf_header *ospfh)
377{
378  if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
379    return (ospf_nbr_lookup_by_routerid (oi->nbrs, &ospfh->router_id));
380  else
381    return (ospf_nbr_lookup_by_addr (oi->nbrs, &iph->ip_src));
382}
383
384static struct ospf_neighbor *
385ospf_nbr_add (struct ospf_interface *oi, struct ospf_header *ospfh,
386              struct prefix *p)
387{
388  struct ospf_neighbor *nbr;
389
390  nbr = ospf_nbr_new (oi);
391  nbr->state = NSM_Down;
392  nbr->src = p->u.prefix4;
393  memcpy (&nbr->address, p, sizeof (struct prefix));
394
395  nbr->nbr_nbma = NULL;
396  if (oi->type == OSPF_IFTYPE_NBMA)
397    {
398      struct ospf_nbr_nbma *nbr_nbma;
399      struct listnode *node;
400
401      for (ALL_LIST_ELEMENTS_RO (oi->nbr_nbma, node, nbr_nbma))
402        {
403          if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src))
404            {
405              nbr_nbma->nbr = nbr;
406              nbr->nbr_nbma = nbr_nbma;
407
408              if (nbr_nbma->t_poll)
409                OSPF_POLL_TIMER_OFF (nbr_nbma->t_poll);
410
411              nbr->state_change = nbr_nbma->state_change + 1;
412            }
413        }
414    }
415
416  /* New nbr, save the crypto sequence number if necessary */
417  if (ntohs (ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
418    nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
419
420  if (IS_DEBUG_OSPF_EVENT)
421    zlog_debug ("NSM[%s:%s]: start", IF_NAME (nbr->oi),
422               inet_ntoa (nbr->router_id));
423
424  return nbr;
425}
426
427struct ospf_neighbor *
428ospf_nbr_get (struct ospf_interface *oi, struct ospf_header *ospfh,
429              struct ip *iph, struct prefix *p)
430{
431  struct route_node *rn;
432  struct prefix key;
433  struct ospf_neighbor *nbr;
434
435  key.family = AF_INET;
436  key.prefixlen = IPV4_MAX_BITLEN;
437
438  if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
439    key.u.prefix4 = ospfh->router_id;   /* index vlink nbrs by router-id */
440  else
441    key.u.prefix4 = iph->ip_src;
442
443  rn = route_node_get (oi->nbrs, &key);
444  if (rn->info)
445    {
446      route_unlock_node (rn);
447      nbr = rn->info;
448
449      if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt)
450        {
451          nbr->src = iph->ip_src;
452          memcpy (&nbr->address, p, sizeof (struct prefix));
453        }
454    }
455  else
456    {
457      rn->info = nbr = ospf_nbr_add (oi, ospfh, p);
458    }
459
460  nbr->router_id = ospfh->router_id;
461
462  return nbr;
463}
464