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