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 along
  18  * with this program; see the file COPYING; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include <zebra.h>
  23
  24 #include "linklist.h"
  25 #include "prefix.h"
  26 #include "memory.h"
  27 #include "command.h"
  28 #include "thread.h"
  29 #include "stream.h"
  30 #include "table.h"
  31 #include "log.h"
  32 #include "json.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 #include "ospfd/ospf_bfd.h"
  46
  47 /* Fill in the the 'key' as appropriate to retrieve the entry for nbr
  48  * from the ospf_interface's nbrs table. Indexed by interface address
  49  * for all cases except Virtual-link and PointToPoint interfaces, where
  50  * neighbours are indexed by router-ID instead.
  51  */
  52 static void
  53 ospf_nbr_key (struct ospf_interface *oi, struct ospf_neighbor *nbr,
  54               struct prefix *key)
  55 {
  56   key->family = AF_INET;
  57   key->prefixlen = IPV4_MAX_BITLEN;
  58
  59   /* vlinks are indexed by router-id */
  60   if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
  61       oi->type == OSPF_IFTYPE_POINTOPOINT)
  62     key->u.prefix4 = nbr->router_id;
  63   else
  64     key->u.prefix4 = nbr->src;
  65   return;
  66 }
  67
  68 struct ospf_neighbor *
  69 ospf_nbr_new (struct ospf_interface *oi)
  70 {
  71   struct ospf_neighbor *nbr;
  72
  73   /* Allcate new neighbor. */
  74   nbr = XCALLOC (MTYPE_OSPF_NEIGHBOR, sizeof (struct ospf_neighbor));
  75
  76   /* Relate neighbor to the interface. */
  77   nbr->oi = oi;
  78
  79   /* Set default values. */
  80   nbr->state = NSM_Down;
  81
  82   /* Set inheritance values. */
  83   nbr->v_inactivity = OSPF_IF_PARAM (oi, v_wait);
  84   nbr->v_db_desc = OSPF_IF_PARAM (oi, retransmit_interval);
  85   nbr->v_ls_req = OSPF_IF_PARAM (oi, retransmit_interval);
  86   nbr->v_ls_upd = OSPF_IF_PARAM (oi, retransmit_interval);
  87   nbr->priority = -1;
  88
  89   /* DD flags. */
  90   nbr->dd_flags = OSPF_DD_FLAG_MS|OSPF_DD_FLAG_M|OSPF_DD_FLAG_I;
  91
  92   /* Last received and sent DD. */
  93   nbr->last_send = NULL;
  94
  95   nbr->nbr_nbma = NULL;
  96
  97   ospf_lsdb_init (&nbr->db_sum);
  98   ospf_lsdb_init (&nbr->ls_rxmt);
  99   ospf_lsdb_init (&nbr->ls_req);
 100
 101   nbr->crypt_seqnum = 0;
 102
 103   ospf_bfd_info_nbr_create(oi, nbr);
 104   return nbr;
 105 }
 106
 107 void
 108 ospf_nbr_free (struct ospf_neighbor *nbr)
 109 {
 110   /* Free DB summary list. */
 111   if (ospf_db_summary_count (nbr))
 112     ospf_db_summary_clear (nbr);
 113     /* ospf_db_summary_delete_all (nbr); */
 114
 115   /* Free ls request list. */
 116   if (ospf_ls_request_count (nbr))
 117     ospf_ls_request_delete_all (nbr);
 118
 119   /* Free retransmit list. */
 120   if (ospf_ls_retransmit_count (nbr))
 121     ospf_ls_retransmit_clear (nbr);
 122
 123   /* Cleanup LSDBs. */
 124   ospf_lsdb_cleanup (&nbr->db_sum);
 125   ospf_lsdb_cleanup (&nbr->ls_req);
 126   ospf_lsdb_cleanup (&nbr->ls_rxmt);
 127
 128   /* Clear last send packet. */
 129   if (nbr->last_send)
 130     ospf_packet_free (nbr->last_send);
 131
 132   if (nbr->nbr_nbma)
 133     {
 134       nbr->nbr_nbma->nbr = NULL;
 135       nbr->nbr_nbma = NULL;
 136     }
 137
 138   /* Cancel all timers. */
 139   OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
 140   OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 141   OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
 142   OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 143
 144   /* Cancel all events. *//* Thread lookup cost would be negligible. */
 145   thread_cancel_event (master, nbr);
 146
 147   ospf_bfd_info_free(&nbr->bfd_info);
 148   XFREE (MTYPE_OSPF_NEIGHBOR, nbr);
 149 }
 150
 151 /* Delete specified OSPF neighbor from interface. */
 152 void
 153 ospf_nbr_delete (struct ospf_neighbor *nbr)
 154 {
 155   struct ospf_interface *oi;
 156   struct route_node *rn;
 157   struct prefix p;
 158
 159   oi = nbr->oi;
 160
 161   /* get appropriate prefix 'key' */
 162   ospf_nbr_key (oi, nbr, &p);
 163
 164   rn = route_node_lookup (oi->nbrs, &p);
 165   if (rn)
 166     {
 167       /* If lookup for a NBR succeeds, the leaf route_node could
 168        * only exist because there is (or was) a nbr there.
 169        * If the nbr was deleted, the leaf route_node should have
 170        * lost its last refcount too, and be deleted.
 171        * Therefore a looked-up leaf route_node in nbrs table
 172        * should never have NULL info.
 173        */
 174       assert (rn->info);
 175
 176       if (rn->info)
 177         {
 178           rn->info = NULL;
 179           route_unlock_node (rn);
 180         }
 181       else
 182         zlog_info ("Can't find neighbor %s in the interface %s",
 183                    inet_ntoa (nbr->src), IF_NAME (oi));
 184
 185       route_unlock_node (rn);
 186     }
 187   else
 188     {
 189       /*
 190        * This neighbor was not found, but before we move on and
 191        * free the neighbor structre, make sure that it was not
 192        * indexed incorrectly and ended up in the "worng" place
 193        */
 194
 195       /* Reverse the lookup rules */
 196       if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
 197           oi->type == OSPF_IFTYPE_POINTOPOINT)
 198         p.u.prefix4 = nbr->src;
 199       else
 200         p.u.prefix4 = nbr->router_id;
 201
 202       rn = route_node_lookup (oi->nbrs, &p);
 203       if (rn){
 204         /* We found the neighbor!
 205          * Now make sure it is not the exact same neighbor
 206          * structure that we are about to free
 207          */
 208         if (nbr == rn->info){
 209           /* Same neighbor, drop the reference to it */
 210           rn->info = NULL;
 211           route_unlock_node (rn);
 212         }
 213         route_unlock_node (rn);
 214       }
 215     }
 216
 217   /* Free ospf_neighbor structure. */
 218   ospf_nbr_free (nbr);
 219 }
 220
 221 /* Check myself is in the neighbor list. */
 222 int
 223 ospf_nbr_bidirectional (struct in_addr *router_id,
 224                         struct in_addr *neighbors, int size)
 225 {
 226   int i;
 227   int max;
 228
 229   max = size / sizeof (struct in_addr);
 230
 231   for (i = 0; i < max; i ++)
 232     if (IPV4_ADDR_SAME (router_id, &neighbors[i]))
 233       return 1;
 234
 235   return 0;
 236 }
 237
 238 /* reset nbr_self */
 239 void
 240 ospf_nbr_self_reset (struct ospf_interface *oi, struct in_addr router_id)
 241 {
 242   if (oi->nbr_self)
 243     ospf_nbr_delete (oi->nbr_self);
 244
 245   oi->nbr_self = ospf_nbr_new (oi);
 246   ospf_nbr_add_self (oi, router_id);
 247 }
 248
 249 /* Add self to nbr list. */
 250 void
 251 ospf_nbr_add_self (struct ospf_interface *oi, struct in_addr router_id)
 252 {
 253   struct prefix p;
 254   struct route_node *rn;
 255
 256   if (!oi->nbr_self)
 257     oi->nbr_self = ospf_nbr_new (oi);
 258
 259   /* Initial state */
 260   oi->nbr_self->address = *oi->address;
 261   oi->nbr_self->priority = OSPF_IF_PARAM (oi, priority);
 262   oi->nbr_self->router_id = router_id;
 263   oi->nbr_self->src = oi->address->u.prefix4;
 264   oi->nbr_self->state = NSM_TwoWay;
 265
 266   switch (oi->area->external_routing)
 267     {
 268       case OSPF_AREA_DEFAULT:
 269         SET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
 270         break;
 271       case OSPF_AREA_STUB:
 272         UNSET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
 273         break;
 274       case OSPF_AREA_NSSA:
 275         UNSET_FLAG (oi->nbr_self->options, OSPF_OPTION_E);
 276         SET_FLAG (oi->nbr_self->options, OSPF_OPTION_NP);
 277         break;
 278     }
 279
 280   /* Add nbr_self to nbrs table */
 281   ospf_nbr_key (oi, oi->nbr_self, &p);
 282
 283   rn = route_node_get (oi->nbrs, &p);
 284   if (rn->info)
 285     {
 286       /* There is already pseudo neighbor. */
 287       assert (oi->nbr_self == rn->info);
 288       route_unlock_node (rn);
 289     }
 290   else
 291     rn->info = oi->nbr_self;
 292 }
 293
 294 /* Get neighbor count by status.
 295    Specify status = 0, get all neighbor other than myself. */
 296 int
 297 ospf_nbr_count (struct ospf_interface *oi, int state)
 298 {
 299   struct ospf_neighbor *nbr;
 300   struct route_node *rn;
 301   int count = 0;
 302
 303   for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
 304     if ((nbr = rn->info))
 305       if (!IPV4_ADDR_SAME (&nbr->router_id, &oi->ospf->router_id))
 306         if (state == 0 || nbr->state == state)
 307           count++;
 308
 309   return count;
 310 }
 311
 312 int
 313 ospf_nbr_count_opaque_capable (struct ospf_interface *oi)
 314 {
 315   struct ospf_neighbor *nbr;
 316   struct route_node *rn;
 317   int count = 0;
 318
 319   for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
 320     if ((nbr = rn->info))
 321       if (!IPV4_ADDR_SAME (&nbr->router_id, &oi->ospf->router_id))
 322         if (nbr->state == NSM_Full)
 323           if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 324             count++;
 325
 326   return count;
 327 }
 328
 329 /* lookup nbr by address - use this only if you know you must
 330  * otherwise use the ospf_nbr_lookup() wrapper, which deals
 331  * with virtual link and PointToPoint neighbours
 332  */
 333 struct ospf_neighbor *
 334 ospf_nbr_lookup_by_addr (struct route_table *nbrs,
 335                          struct in_addr *addr)
 336 {
 337   struct prefix p;
 338   struct route_node *rn;
 339   struct ospf_neighbor *nbr;
 340
 341   p.family = AF_INET;
 342   p.prefixlen = IPV4_MAX_BITLEN;
 343   p.u.prefix4 = *addr;
 344
 345   rn = route_node_lookup (nbrs, &p);
 346   if (! rn)
 347     return NULL;
 348
 349   /* See comment in ospf_nbr_delete */
 350   assert (rn->info);
 351
 352   if (rn->info == NULL)
 353     {
 354       route_unlock_node (rn);
 355       return NULL;
 356     }
 357
 358   nbr = (struct ospf_neighbor *) rn->info;
 359   route_unlock_node (rn);
 360
 361   return nbr;
 362 }
 363
 364 struct ospf_neighbor *
 365 ospf_nbr_lookup_by_routerid (struct route_table *nbrs,
 366                              struct in_addr *id)
 367 {
 368   struct route_node *rn;
 369   struct ospf_neighbor *nbr;
 370
 371   for (rn = route_top (nbrs); rn; rn = route_next (rn))
 372     if ((nbr = rn->info) != NULL)
 373       if (IPV4_ADDR_SAME (&nbr->router_id, id))
 374         {
 375           route_unlock_node(rn);
 376           return nbr;
 377         }
 378
 379   return NULL;
 380 }
 381
 382 void
 383 ospf_renegotiate_optional_capabilities (struct ospf *top)
 384 {
 385   struct listnode *node;
 386   struct ospf_interface *oi;
 387   struct route_table *nbrs;
 388   struct route_node *rn;
 389   struct ospf_neighbor *nbr;
 390
 391   /* At first, flush self-originated LSAs from routing domain. */
 392   ospf_flush_self_originated_lsas_now (top);
 393
 394   /* Revert all neighbor status to ExStart. */
 395   for (ALL_LIST_ELEMENTS_RO (top->oiflist, node, oi))
 396     {
 397       if ((nbrs = oi->nbrs) == NULL)
 398         continue;
 399
 400       for (rn = route_top (nbrs); rn; rn = route_next (rn))
 401         {
 402           if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
 403             continue;
 404
 405           if (nbr->state < NSM_ExStart)
 406             continue;
 407
 408           if (IS_DEBUG_OSPF_EVENT)
 409             zlog_debug ("Renegotiate optional capabilities with neighbor(%s)", inet_ntoa (nbr->router_id));
 410
 411           OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_SeqNumberMismatch);
 412         }
 413     }
 414
 415   return;
 416 }
 417
 418
 419 struct ospf_neighbor *
 420 ospf_nbr_lookup (struct ospf_interface *oi, struct ip *iph,
 421                  struct ospf_header *ospfh)
 422 {
 423   if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
 424       oi->type == OSPF_IFTYPE_POINTOPOINT)
 425     return (ospf_nbr_lookup_by_routerid (oi->nbrs, &ospfh->router_id));
 426   else
 427     return (ospf_nbr_lookup_by_addr (oi->nbrs, &iph->ip_src));
 428 }
 429
 430 static struct ospf_neighbor *
 431 ospf_nbr_add (struct ospf_interface *oi, struct ospf_header *ospfh,
 432               struct prefix *p)
 433 {
 434   struct ospf_neighbor *nbr;
 435
 436   nbr = ospf_nbr_new (oi);
 437   nbr->state = NSM_Down;
 438   nbr->src = p->u.prefix4;
 439   memcpy (&nbr->address, p, sizeof (struct prefix));
 440
 441   nbr->nbr_nbma = NULL;
 442   if (oi->type == OSPF_IFTYPE_NBMA)
 443     {
 444       struct ospf_nbr_nbma *nbr_nbma;
 445       struct listnode *node;
 446
 447       for (ALL_LIST_ELEMENTS_RO (oi->nbr_nbma, node, nbr_nbma))
 448         {
 449           if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src))
 450             {
 451               nbr_nbma->nbr = nbr;
 452               nbr->nbr_nbma = nbr_nbma;
 453
 454               if (nbr_nbma->t_poll)
 455                 OSPF_POLL_TIMER_OFF (nbr_nbma->t_poll);
 456
 457               nbr->state_change = nbr_nbma->state_change + 1;
 458             }
 459         }
 460     }
 461
 462   /* New nbr, save the crypto sequence number if necessary */
 463   if (ntohs (ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
 464     nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
 465
 466   if (IS_DEBUG_OSPF_EVENT)
 467     zlog_debug ("NSM[%s:%s]: start", IF_NAME (nbr->oi),
 468                inet_ntoa (nbr->router_id));
 469
 470   return nbr;
 471 }
 472
 473 struct ospf_neighbor *
 474 ospf_nbr_get (struct ospf_interface *oi, struct ospf_header *ospfh,
 475               struct ip *iph, struct prefix *p)
 476 {
 477   struct route_node *rn;
 478   struct prefix key;
 479   struct ospf_neighbor *nbr;
 480
 481   key.family = AF_INET;
 482   key.prefixlen = IPV4_MAX_BITLEN;
 483
 484   if (oi->type == OSPF_IFTYPE_VIRTUALLINK ||
 485       oi->type == OSPF_IFTYPE_POINTOPOINT)
 486     key.u.prefix4 = ospfh->router_id;/* index vlink and ptp nbrs by router-id */
 487   else
 488     key.u.prefix4 = iph->ip_src;
 489
 490   rn = route_node_get (oi->nbrs, &key);
 491   if (rn->info)
 492     {
 493       route_unlock_node (rn);
 494       nbr = rn->info;
 495
 496       if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt)
 497         {
 498           nbr->src = iph->ip_src;
 499           memcpy (&nbr->address, p, sizeof (struct prefix));
 500         }
 501     }
 502   else
 503     {
 504       rn->info = nbr = ospf_nbr_add (oi, ospfh, p);
 505     }
 506
 507   nbr->router_id = ospfh->router_id;
 508
 509   return nbr;
 510 }