ospfd/ospf_neighbor.c

   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 #include "json.h"
  34
  35 #include "ospfd/ospfd.h"
  36 #include "ospfd/ospf_interface.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_packet.h"
  43 #include "ospfd/ospf_network.h"
  44 #include "ospfd/ospf_flood.h"
  45 #include "ospfd/ospf_dump.h"
  46 #include "ospfd/ospf_bfd.h"
  47
  48 /* Fill in the the 'key' as appropriate to retrieve the entry for nbr
  49  * from the ospf_interface's nbrs table. Indexed by interface address
  50  * for all cases except Virtual-link and PointToPoint interfaces, where
  51  * neighbours are indexed by router-ID instead.
  52  */
  53 static void
  54 ospf_nbr_key (struct ospf_interface *oi, struct ospf_neighbor *nbr,
  55               struct prefix *key)
  56 {
  57   key->family = AF_INET;
  58   key->prefixlen = IPV4_MAX_BITLEN;
  59
  60   /* vlinks are indexed by router-id */
  61   if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
  62       oi->type == OSPF_IFTYPE_POINTOPOINT)
  63     key->u.prefix4 = nbr->router_id;
  64   else
  65     key->u.prefix4 = nbr->src;
  66   return;
  67 }
  68
  69 struct ospf_neighbor *
  70 ospf_nbr_new (struct ospf_interface *oi)
  71 {
  72   struct ospf_neighbor *nbr;
  73
  74   /* Allcate new neighbor. */
  75   nbr = XCALLOC (MTYPE_OSPF_NEIGHBOR, sizeof (struct ospf_neighbor));
  76
  77   /* Relate neighbor to the interface. */
  78   nbr->oi = oi;
  79
  80   /* Set default values. */
  81   nbr->state = NSM_Down;
  82
  83   /* Set inheritance values. */
  84   nbr->v_inactivity = OSPF_IF_PARAM (oi, v_wait);
  85   nbr->v_db_desc = OSPF_IF_PARAM (oi, retransmit_interval);
  86   nbr->v_ls_req = OSPF_IF_PARAM (oi, retransmit_interval);
  87   nbr->v_ls_upd = OSPF_IF_PARAM (oi, retransmit_interval);
  88   nbr->priority = -1;
  89
  90   /* DD flags. */
  91   nbr->dd_flags = OSPF_DD_FLAG_MS|OSPF_DD_FLAG_M|OSPF_DD_FLAG_I;
  92
  93   /* Last received and sent DD. */
  94   nbr->last_send = NULL;
  95
  96   nbr->nbr_nbma = NULL;
  97
  98   ospf_lsdb_init (&nbr->db_sum);
  99   ospf_lsdb_init (&nbr->ls_rxmt);
 100   ospf_lsdb_init (&nbr->ls_req);
 101
 102   nbr->crypt_seqnum = 0;
 103
 104   ospf_bfd_info_nbr_create(oi, nbr);
 105   return nbr;
 106 }
 107
 108 void
 109 ospf_nbr_free (struct ospf_neighbor *nbr)
 110 {
 111   /* Free DB summary list. */
 112   if (ospf_db_summary_count (nbr))
 113     ospf_db_summary_clear (nbr);
 114     /* ospf_db_summary_delete_all (nbr); */
 115
 116   /* Free ls request list. */
 117   if (ospf_ls_request_count (nbr))
 118     ospf_ls_request_delete_all (nbr);
 119
 120   /* Free retransmit list. */
 121   if (ospf_ls_retransmit_count (nbr))
 122     ospf_ls_retransmit_clear (nbr);
 123
 124   /* Cleanup LSDBs. */
 125   ospf_lsdb_cleanup (&nbr->db_sum);
 126   ospf_lsdb_cleanup (&nbr->ls_req);
 127   ospf_lsdb_cleanup (&nbr->ls_rxmt);
 128
 129   /* Clear last send packet. */
 130   if (nbr->last_send)
 131     ospf_packet_free (nbr->last_send);
 132
 133   if (nbr->nbr_nbma)
 134     {
 135       nbr->nbr_nbma->nbr = NULL;
 136       nbr->nbr_nbma = NULL;
 137     }
 138
 139   /* Cancel all timers. */
 140   OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
 141   OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 142   OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
 143   OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 144
 145   /* Cancel all events. *//* Thread lookup cost would be negligible. */
 146   thread_cancel_event (master, nbr);
 147
 148   ospf_bfd_info_free(&nbr->bfd_info);
 149   XFREE (MTYPE_OSPF_NEIGHBOR, nbr);
 150 }
 151
 152 /* Delete specified OSPF neighbor from interface. */
 153 void
 154 ospf_nbr_delete (struct ospf_neighbor *nbr)
 155 {
 156   struct ospf_interface *oi;
 157   struct route_node *rn;
 158   struct prefix p;
 159
 160   oi = nbr->oi;
 161
 162   /* get appropriate prefix 'key' */
 163   ospf_nbr_key (oi, nbr, &p);
 164
 165   rn = route_node_lookup (oi->nbrs, &p);
 166   if (rn)
 167     {
 168       /* If lookup for a NBR succeeds, the leaf route_node could
 169        * only exist because there is (or was) a nbr there.
 170        * If the nbr was deleted, the leaf route_node should have
 171        * lost its last refcount too, and be deleted.
 172        * Therefore a looked-up leaf route_node in nbrs table
 173        * should never have NULL info.
 174        */
 175       assert (rn->info);
 176
 177       if (rn->info)
 178         {
 179           rn->info = NULL;
 180           route_unlock_node (rn);
 181         }
 182       else
 183         zlog_info ("Can't find neighbor %s in the interface %s",
 184                    inet_ntoa (nbr->src), IF_NAME (oi));
 185
 186       route_unlock_node (rn);
 187     }
 188   else
 189     {
 190       /*
 191        * This neighbor was not found, but before we move on and
 192        * free the neighbor structre, make sure that it was not
 193        * indexed incorrectly and ended up in the "worng" place
 194        */
 195
 196       /* Reverse the lookup rules */
 197       if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
 198           oi->type == OSPF_IFTYPE_POINTOPOINT)
 199         p.u.prefix4 = nbr->src;
 200       else
 201         p.u.prefix4 = nbr->router_id;
 202
 203       rn = route_node_lookup (oi->nbrs, &p);
 204       if (rn){
 205         /* We found the neighbor!
 206          * Now make sure it is not the exact same neighbor
 207          * structure that we are about to free
 208          */
 209         if (nbr == rn->info){
 210           /* Same neighbor, drop the reference to it */
 211           rn->info = NULL;
 212           route_unlock_node (rn);
 213         }
 214         route_unlock_node (rn);
 215       }
 216     }
 217
 218   /* Free ospf_neighbor structure. */
 219   ospf_nbr_free (nbr);
 220 }
 221
 222 /* Check myself is in the neighbor list. */
 223 int
 224 ospf_nbr_bidirectional (struct in_addr *router_id,
 225                         struct in_addr *neighbors, int size)
 226 {
 227   int i;
 228   int max;
 229
 230   max = size / sizeof (struct in_addr);
 231
 232   for (i = 0; i < max; i ++)
 233     if (IPV4_ADDR_SAME (router_id, &neighbors[i]))
 234       return 1;
 235
 236   return 0;
 237 }
 238
 239 /* reset nbr_self */
 240 void
 241 ospf_nbr_self_reset (struct ospf_interface *oi, struct in_addr router_id)
 242 {
 243   if (oi->nbr_self)
 244     ospf_nbr_delete (oi->nbr_self);
 245
 246   oi->nbr_self = ospf_nbr_new (oi);
 247   ospf_nbr_add_self (oi, router_id);
 248 }
 249
 250 /* Add self to nbr list. */
 251 void
 252 ospf_nbr_add_self (struct ospf_interface *oi, struct in_addr router_id)
 253 {
 254   struct prefix p;
 255   struct route_node *rn;
 256
 257   if (!oi->nbr_self)
 258     oi->nbr_self = ospf_nbr_new (oi);
 259
 260   /* Initial state */
 261   oi->nbr_self->address = *oi->address;
 262   oi->nbr_self->priority = OSPF_IF_PARAM (oi, priority);
 263   oi->nbr_self->router_id = router_id;
 264   oi->nbr_self->src = oi->address->u.prefix4;
 265   oi->nbr_self->state = NSM_TwoWay;
 266
 267   switch (oi->area->external_routing)
 268     {
 269       case OSPF_AREA_DEFAULT:
 270         SET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
 271         break;
 272       case OSPF_AREA_STUB:
 273         UNSET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
 274         break;
 275       case OSPF_AREA_NSSA:
 276         UNSET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
 277         SET_FLAG (oi->nbr_self->options, OSPF_OPTION_NP);
 278         break;
 279     }
 280
 281   /* Add nbr_self to nbrs table */
 282   ospf_nbr_key (oi, oi->nbr_self, &p);
 283
 284   rn = route_node_get (oi->nbrs, &p);
 285   if (rn->info)
 286     {
 287       /* There is already pseudo neighbor. */
 288       assert (oi->nbr_self == rn->info);
 289       route_unlock_node (rn);
 290     }
 291   else
 292     rn->info = oi->nbr_self;
 293 }
 294
 295 /* Get neighbor count by status.
 296    Specify status = 0, get all neighbor other than myself. */
 297 int
 298 ospf_nbr_count (struct ospf_interface *oi, int state)
 299 {
 300   struct ospf_neighbor *nbr;
 301   struct route_node *rn;
 302   int count = 0;
 303
 304   for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
 305     if ((nbr = rn->info))
 306       if (!IPV4_ADDR_SAME (&nbr->router_id, &oi->ospf->router_id))
 307         if (state == 0 || nbr->state == state)
 308           count++;
 309
 310   return count;
 311 }
 312
 313 int
 314 ospf_nbr_count_opaque_capable (struct ospf_interface *oi)
 315 {
 316   struct ospf_neighbor *nbr;
 317   struct route_node *rn;
 318   int count = 0;
 319
 320   for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
 321     if ((nbr = rn->info))
 322       if (!IPV4_ADDR_SAME (&nbr->router_id, &oi->ospf->router_id))
 323         if (nbr->state == NSM_Full)
 324           if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 325             count++;
 326
 327   return count;
 328 }
 329
 330 /* lookup nbr by address - use this only if you know you must
 331  * otherwise use the ospf_nbr_lookup() wrapper, which deals
 332  * with virtual link and PointToPoint neighbours
 333  */
 334 struct ospf_neighbor *
 335 ospf_nbr_lookup_by_addr (struct route_table *nbrs,
 336                          struct in_addr *addr)
 337 {
 338   struct prefix p;
 339   struct route_node *rn;
 340   struct ospf_neighbor *nbr;
 341
 342   p.family = AF_INET;
 343   p.prefixlen = IPV4_MAX_BITLEN;
 344   p.u.prefix4 = *addr;
 345
 346   rn = route_node_lookup (nbrs, &p);
 347   if (! rn)
 348     return NULL;
 349
 350   /* See comment in ospf_nbr_delete */
 351   assert (rn->info);
 352
 353   if (rn->info == NULL)
 354     {
 355       route_unlock_node (rn);
 356       return NULL;
 357     }
 358
 359   nbr = (struct ospf_neighbor *) rn->info;
 360   route_unlock_node (rn);
 361
 362   return nbr;
 363 }
 364
 365 struct ospf_neighbor *
 366 ospf_nbr_lookup_by_routerid (struct route_table *nbrs,
 367                              struct in_addr *id)
 368 {
 369   struct route_node *rn;
 370   struct ospf_neighbor *nbr;
 371
 372   for (rn = route_top (nbrs); rn; rn = route_next (rn))
 373     if ((nbr = rn->info) != NULL)
 374       if (IPV4_ADDR_SAME (&nbr->router_id, id))
 375         {
 376           route_unlock_node(rn);
 377           return nbr;
 378         }
 379
 380   return NULL;
 381 }
 382
 383 void
 384 ospf_renegotiate_optional_capabilities (struct ospf *top)
 385 {
 386   struct listnode *node;
 387   struct ospf_interface *oi;
 388   struct route_table *nbrs;
 389   struct route_node *rn;
 390   struct ospf_neighbor *nbr;
 391
 392   /* At first, flush self-originated LSAs from routing domain. */
 393   ospf_flush_self_originated_lsas_now (top);
 394
 395   /* Revert all neighbor status to ExStart. */
 396   for (ALL_LIST_ELEMENTS_RO (top->oiflist, node, oi))
 397     {
 398       if ((nbrs = oi->nbrs) == NULL)
 399         continue;
 400
 401       for (rn = route_top (nbrs); rn; rn = route_next (rn))
 402         {
 403           if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
 404             continue;
 405
 406           if (nbr->state < NSM_ExStart)
 407             continue;
 408
 409           if (IS_DEBUG_OSPF_EVENT)
 410             zlog_debug ("Renegotiate optional capabilities with neighbor(%s)", inet_ntoa (nbr->router_id));
 411
 412           OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_SeqNumberMismatch);
 413         }
 414     }
 415
 416   return;
 417 }
 418
 419
 420 struct ospf_neighbor *
 421 ospf_nbr_lookup (struct ospf_interface *oi, struct ip *iph,
 422                  struct ospf_header *ospfh)
 423 {
 424   if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
 425       oi->type == OSPF_IFTYPE_POINTOPOINT)
 426     return (ospf_nbr_lookup_by_routerid (oi->nbrs, &ospfh->router_id));
 427   else
 428     return (ospf_nbr_lookup_by_addr (oi->nbrs, &iph->ip_src));
 429 }
 430
 431 static struct ospf_neighbor *
 432 ospf_nbr_add (struct ospf_interface *oi, struct ospf_header *ospfh,
 433               struct prefix *p)
 434 {
 435   struct ospf_neighbor *nbr;
 436
 437   nbr = ospf_nbr_new (oi);
 438   nbr->state = NSM_Down;
 439   nbr->src = p->u.prefix4;
 440   memcpy (&nbr->address, p, sizeof (struct prefix));
 441
 442   nbr->nbr_nbma = NULL;
 443   if (oi->type == OSPF_IFTYPE_NBMA)
 444     {
 445       struct ospf_nbr_nbma *nbr_nbma;
 446       struct listnode *node;
 447
 448       for (ALL_LIST_ELEMENTS_RO (oi->nbr_nbma, node, nbr_nbma))
 449         {
 450           if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src))
 451             {
 452               nbr_nbma->nbr = nbr;
 453               nbr->nbr_nbma = nbr_nbma;
 454
 455               if (nbr_nbma->t_poll)
 456                 OSPF_POLL_TIMER_OFF (nbr_nbma->t_poll);
 457
 458               nbr->state_change = nbr_nbma->state_change + 1;
 459             }
 460         }
 461     }
 462
 463   /* New nbr, save the crypto sequence number if necessary */
 464   if (ntohs (ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
 465     nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
 466
 467   if (IS_DEBUG_OSPF_EVENT)
 468     zlog_debug ("NSM[%s:%s]: start", IF_NAME (nbr->oi),
 469                inet_ntoa (nbr->router_id));
 470
 471   return nbr;
 472 }
 473
 474 struct ospf_neighbor *
 475 ospf_nbr_get (struct ospf_interface *oi, struct ospf_header *ospfh,
 476               struct ip *iph, struct prefix *p)
 477 {
 478   struct route_node *rn;
 479   struct prefix key;
 480   struct ospf_neighbor *nbr;
 481
 482   key.family = AF_INET;
 483   key.prefixlen = IPV4_MAX_BITLEN;
 484
 485   if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
 486       oi->type == OSPF_IFTYPE_POINTOPOINT)
 487     key.u.prefix4 = ospfh->router_id;/* index vlink and ptp nbrs by router-id */
 488   else
 489     key.u.prefix4 = iph->ip_src;
 490
 491   rn = route_node_get (oi->nbrs, &key);
 492   if (rn->info)
 493     {
 494       route_unlock_node (rn);
 495       nbr = rn->info;
 496
 497       if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt)
 498         {
 499           nbr->src = iph->ip_src;
 500           memcpy (&nbr->address, p, sizeof (struct prefix));
 501         }
 502     }
 503   else
 504     {
 505       rn->info = nbr = ospf_nbr_add (oi, ospfh, p);
 506     }
 507
 508   nbr->router_id = ospfh->router_id;
 509
 510   return nbr;
 511 }