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 = 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
 104 void
 105 ospf_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. */
 148 void
 149 ospf_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. */
 189 int
 190 ospf_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. */
 206 void
 207 ospf_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. */
 249 int
 250 ospf_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
 266 int
 267 ospf_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  */
 288 struct ospf_neighbor *
 289 ospf_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
 319 struct ospf_neighbor *
 320 ospf_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
 337 void
 338 ospf_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
 374 struct ospf_neighbor *
 375 ospf_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
 384 static struct ospf_neighbor *
 385 ospf_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
 427 struct ospf_neighbor *
 428 ospf_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 }