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 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             || oi->type == OSPF_IFTYPE_POINTOPOINT)
  61                 key->u.prefix4 = nbr->router_id;
  62         else
  63                 key->u.prefix4 = nbr->src;
  64         return;
  65 }
  66
  67 struct ospf_neighbor *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         ospf_bfd_info_nbr_create(oi, nbr);
 102         return nbr;
 103 }
 104
 105 void 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                 nbr->nbr_nbma->nbr = NULL;
 131                 nbr->nbr_nbma = NULL;
 132         }
 133
 134         /* Cancel all timers. */
 135         OSPF_NSM_TIMER_OFF(nbr->t_inactivity);
 136         OSPF_NSM_TIMER_OFF(nbr->t_db_desc);
 137         OSPF_NSM_TIMER_OFF(nbr->t_ls_req);
 138         OSPF_NSM_TIMER_OFF(nbr->t_ls_upd);
 139
 140         /* Cancel all events. */ /* Thread lookup cost would be negligible. */
 141         thread_cancel_event(master, nbr);
 142
 143         ospf_bfd_info_free(&nbr->bfd_info);
 144         XFREE(MTYPE_OSPF_NEIGHBOR, nbr);
 145 }
 146
 147 /* Delete specified OSPF neighbor from interface. */
 148 void ospf_nbr_delete(struct ospf_neighbor *nbr)
 149 {
 150         struct ospf_interface *oi;
 151         struct route_node *rn;
 152         struct prefix p;
 153
 154         oi = nbr->oi;
 155
 156         /* get appropriate prefix 'key' */
 157         ospf_nbr_key(oi, nbr, &p);
 158
 159         rn = route_node_lookup(oi->nbrs, &p);
 160         if (rn) {
 161                 /* If lookup for a NBR succeeds, the leaf route_node could
 162                  * only exist because there is (or was) a nbr there.
 163                  * If the nbr was deleted, the leaf route_node should have
 164                  * lost its last refcount too, and be deleted.
 165                  * Therefore a looked-up leaf route_node in nbrs table
 166                  * should never have NULL info.
 167                  */
 168                 assert(rn->info);
 169
 170                 if (rn->info) {
 171                         rn->info = NULL;
 172                         route_unlock_node(rn);
 173                 } else
 174                         zlog_info("Can't find neighbor %s in the interface %s",
 175                                   inet_ntoa(nbr->src), IF_NAME(oi));
 176
 177                 route_unlock_node(rn);
 178         } else {
 179                 /*
 180                  * This neighbor was not found, but before we move on and
 181                  * free the neighbor structre, make sure that it was not
 182                  * indexed incorrectly and ended up in the "worng" place
 183                  */
 184
 185                 /* Reverse the lookup rules */
 186                 if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 187                     || oi->type == OSPF_IFTYPE_POINTOPOINT)
 188                         p.u.prefix4 = nbr->src;
 189                 else
 190                         p.u.prefix4 = nbr->router_id;
 191
 192                 rn = route_node_lookup(oi->nbrs, &p);
 193                 if (rn) {
 194                         /* We found the neighbor!
 195                          * Now make sure it is not the exact same neighbor
 196                          * structure that we are about to free
 197                          */
 198                         if (nbr == rn->info) {
 199                                 /* Same neighbor, drop the reference to it */
 200                                 rn->info = NULL;
 201                                 route_unlock_node(rn);
 202                         }
 203                         route_unlock_node(rn);
 204                 }
 205         }
 206
 207         /* Free ospf_neighbor structure. */
 208         ospf_nbr_free(nbr);
 209 }
 210
 211 /* Check myself is in the neighbor list. */
 212 int ospf_nbr_bidirectional(struct in_addr *router_id, struct in_addr *neighbors,
 213                            int size)
 214 {
 215         int i;
 216         int max;
 217
 218         max = size / sizeof(struct in_addr);
 219
 220         for (i = 0; i < max; i++)
 221                 if (IPV4_ADDR_SAME(router_id, &neighbors[i]))
 222                         return 1;
 223
 224         return 0;
 225 }
 226
 227 /* reset nbr_self */
 228 void ospf_nbr_self_reset(struct ospf_interface *oi, struct in_addr router_id)
 229 {
 230         if (oi->nbr_self)
 231                 ospf_nbr_delete(oi->nbr_self);
 232
 233         oi->nbr_self = ospf_nbr_new(oi);
 234         ospf_nbr_add_self(oi, router_id);
 235 }
 236
 237 /* Add self to nbr list. */
 238 void ospf_nbr_add_self(struct ospf_interface *oi, struct in_addr router_id)
 239 {
 240         struct prefix p;
 241         struct route_node *rn;
 242
 243         if (!oi->nbr_self)
 244                 oi->nbr_self = ospf_nbr_new(oi);
 245
 246         /* Initial state */
 247         oi->nbr_self->address = *oi->address;
 248         oi->nbr_self->priority = OSPF_IF_PARAM(oi, priority);
 249         oi->nbr_self->router_id = router_id;
 250         oi->nbr_self->src = oi->address->u.prefix4;
 251         oi->nbr_self->state = NSM_TwoWay;
 252
 253         switch (oi->area->external_routing) {
 254         case OSPF_AREA_DEFAULT:
 255                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 256                 break;
 257         case OSPF_AREA_STUB:
 258                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 259                 break;
 260         case OSPF_AREA_NSSA:
 261                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 262                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_NP);
 263                 break;
 264         }
 265
 266         /* Add nbr_self to nbrs table */
 267         ospf_nbr_key(oi, oi->nbr_self, &p);
 268
 269         rn = route_node_get(oi->nbrs, &p);
 270         if (rn->info) {
 271                 /* There is already pseudo neighbor. */
 272                 assert(oi->nbr_self == rn->info);
 273                 route_unlock_node(rn);
 274         } else
 275                 rn->info = oi->nbr_self;
 276 }
 277
 278 /* Get neighbor count by status.
 279    Specify status = 0, get all neighbor other than myself. */
 280 int ospf_nbr_count(struct ospf_interface *oi, int state)
 281 {
 282         struct ospf_neighbor *nbr;
 283         struct route_node *rn;
 284         int count = 0;
 285
 286         for (rn = route_top(oi->nbrs); rn; rn = route_next(rn))
 287                 if ((nbr = rn->info))
 288                         if (!IPV4_ADDR_SAME(&nbr->router_id,
 289                                             &oi->ospf->router_id))
 290                                 if (state == 0 || nbr->state == state)
 291                                         count++;
 292
 293         return count;
 294 }
 295
 296 int ospf_nbr_count_opaque_capable(struct ospf_interface *oi)
 297 {
 298         struct ospf_neighbor *nbr;
 299         struct route_node *rn;
 300         int count = 0;
 301
 302         for (rn = route_top(oi->nbrs); rn; rn = route_next(rn))
 303                 if ((nbr = rn->info))
 304                         if (!IPV4_ADDR_SAME(&nbr->router_id,
 305                                             &oi->ospf->router_id))
 306                                 if (nbr->state == NSM_Full)
 307                                         if (CHECK_FLAG(nbr->options,
 308                                                        OSPF_OPTION_O))
 309                                                 count++;
 310
 311         return count;
 312 }
 313
 314 /* lookup nbr by address - use this only if you know you must
 315  * otherwise use the ospf_nbr_lookup() wrapper, which deals
 316  * with virtual link and PointToPoint neighbours
 317  */
 318 struct ospf_neighbor *ospf_nbr_lookup_by_addr(struct route_table *nbrs,
 319                                               struct in_addr *addr)
 320 {
 321         struct prefix p;
 322         struct route_node *rn;
 323         struct ospf_neighbor *nbr;
 324
 325         p.family = AF_INET;
 326         p.prefixlen = IPV4_MAX_BITLEN;
 327         p.u.prefix4 = *addr;
 328
 329         rn = route_node_lookup(nbrs, &p);
 330         if (!rn)
 331                 return NULL;
 332
 333         /* See comment in ospf_nbr_delete */
 334         assert(rn->info);
 335
 336         if (rn->info == NULL) {
 337                 route_unlock_node(rn);
 338                 return NULL;
 339         }
 340
 341         nbr = (struct ospf_neighbor *)rn->info;
 342         route_unlock_node(rn);
 343
 344         return nbr;
 345 }
 346
 347 struct ospf_neighbor *ospf_nbr_lookup_by_routerid(struct route_table *nbrs,
 348                                                   struct in_addr *id)
 349 {
 350         struct route_node *rn;
 351         struct ospf_neighbor *nbr;
 352
 353         for (rn = route_top(nbrs); rn; rn = route_next(rn))
 354                 if ((nbr = rn->info) != NULL)
 355                         if (IPV4_ADDR_SAME(&nbr->router_id, id)) {
 356                                 route_unlock_node(rn);
 357                                 return nbr;
 358                         }
 359
 360         return NULL;
 361 }
 362
 363 void ospf_renegotiate_optional_capabilities(struct ospf *top)
 364 {
 365         struct listnode *node;
 366         struct ospf_interface *oi;
 367         struct route_table *nbrs;
 368         struct route_node *rn;
 369         struct ospf_neighbor *nbr;
 370
 371         /* At first, flush self-originated LSAs from routing domain. */
 372         ospf_flush_self_originated_lsas_now(top);
 373
 374         /* Revert all neighbor status to ExStart. */
 375         for (ALL_LIST_ELEMENTS_RO(top->oiflist, node, oi)) {
 376                 if ((nbrs = oi->nbrs) == NULL)
 377                         continue;
 378
 379                 for (rn = route_top(nbrs); rn; rn = route_next(rn)) {
 380                         if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
 381                                 continue;
 382
 383                         if (nbr->state < NSM_ExStart)
 384                                 continue;
 385
 386                         if (IS_DEBUG_OSPF_EVENT)
 387                                 zlog_debug(
 388                                         "Renegotiate optional capabilities with neighbor(%s)",
 389                                         inet_ntoa(nbr->router_id));
 390
 391                         OSPF_NSM_EVENT_SCHEDULE(nbr, NSM_SeqNumberMismatch);
 392                 }
 393         }
 394
 395         return;
 396 }
 397
 398
 399 struct ospf_neighbor *ospf_nbr_lookup(struct ospf_interface *oi, struct ip *iph,
 400                                       struct ospf_header *ospfh)
 401 {
 402         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 403             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 404                 return (ospf_nbr_lookup_by_routerid(oi->nbrs,
 405                                                     &ospfh->router_id));
 406         else
 407                 return (ospf_nbr_lookup_by_addr(oi->nbrs, &iph->ip_src));
 408 }
 409
 410 static struct ospf_neighbor *ospf_nbr_add(struct ospf_interface *oi,
 411                                           struct ospf_header *ospfh,
 412                                           struct prefix *p)
 413 {
 414         struct ospf_neighbor *nbr;
 415
 416         nbr = ospf_nbr_new(oi);
 417         nbr->state = NSM_Down;
 418         nbr->src = p->u.prefix4;
 419         memcpy(&nbr->address, p, sizeof(struct prefix));
 420
 421         nbr->nbr_nbma = NULL;
 422         if (oi->type == OSPF_IFTYPE_NBMA) {
 423                 struct ospf_nbr_nbma *nbr_nbma;
 424                 struct listnode *node;
 425
 426                 for (ALL_LIST_ELEMENTS_RO(oi->nbr_nbma, node, nbr_nbma)) {
 427                         if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src)) {
 428                                 nbr_nbma->nbr = nbr;
 429                                 nbr->nbr_nbma = nbr_nbma;
 430
 431                                 if (nbr_nbma->t_poll)
 432                                         OSPF_POLL_TIMER_OFF(nbr_nbma->t_poll);
 433
 434                                 nbr->state_change = nbr_nbma->state_change + 1;
 435                         }
 436                 }
 437         }
 438
 439         /* New nbr, save the crypto sequence number if necessary */
 440         if (ntohs(ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
 441                 nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
 442
 443         if (IS_DEBUG_OSPF_EVENT)
 444                 zlog_debug("NSM[%s:%s]: start", IF_NAME(nbr->oi),
 445                            inet_ntoa(nbr->router_id));
 446
 447         return nbr;
 448 }
 449
 450 struct ospf_neighbor *ospf_nbr_get(struct ospf_interface *oi,
 451                                    struct ospf_header *ospfh, struct ip *iph,
 452                                    struct prefix *p)
 453 {
 454         struct route_node *rn;
 455         struct prefix key;
 456         struct ospf_neighbor *nbr;
 457
 458         key.family = AF_INET;
 459         key.prefixlen = IPV4_MAX_BITLEN;
 460
 461         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 462             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 463                 key.u.prefix4 =
 464                         ospfh->router_id; /* index vlink and ptp nbrs by
 465                                              router-id */
 466         else
 467                 key.u.prefix4 = iph->ip_src;
 468
 469         rn = route_node_get(oi->nbrs, &key);
 470         if (rn->info) {
 471                 route_unlock_node(rn);
 472                 nbr = rn->info;
 473
 474                 if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt) {
 475                         nbr->src = iph->ip_src;
 476                         memcpy(&nbr->address, p, sizeof(struct prefix));
 477                 }
 478         } else {
 479                 rn->info = nbr = ospf_nbr_add(oi, ospfh, p);
 480         }
 481
 482         nbr->router_id = ospfh->router_id;
 483
 484         return nbr;
 485 }