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 "lib/bfd.h"
  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 #include "ospfd/ospf_gr_helper.h"
  48
  49 /* Fill in the the 'key' as appropriate to retrieve the entry for nbr
  50  * from the ospf_interface's nbrs table. Indexed by interface address
  51  * for all cases except Virtual-link and PointToPoint interfaces, where
  52  * neighbours are indexed by router-ID instead.
  53  */
  54 static void 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 *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         /* Initialize GR Helper info*/
 104         nbr->gr_helper_info.recvd_grace_period = 0;
 105         nbr->gr_helper_info.actual_grace_period = 0;
 106         nbr->gr_helper_info.gr_helper_status = OSPF_GR_NOT_HELPER;
 107         nbr->gr_helper_info.helper_exit_reason = OSPF_GR_HELPER_EXIT_NONE;
 108         nbr->gr_helper_info.gr_restart_reason = OSPF_GR_UNKNOWN_RESTART;
 109
 110         return nbr;
 111 }
 112
 113 void ospf_nbr_free(struct ospf_neighbor *nbr)
 114 {
 115         /* Free DB summary list. */
 116         if (ospf_db_summary_count(nbr))
 117                 ospf_db_summary_clear(nbr);
 118         /* ospf_db_summary_delete_all (nbr); */
 119
 120         /* Free ls request list. */
 121         if (ospf_ls_request_count(nbr))
 122                 ospf_ls_request_delete_all(nbr);
 123
 124         /* Free retransmit list. */
 125         if (ospf_ls_retransmit_count(nbr))
 126                 ospf_ls_retransmit_clear(nbr);
 127
 128         /* Cleanup LSDBs. */
 129         ospf_lsdb_cleanup(&nbr->db_sum);
 130         ospf_lsdb_cleanup(&nbr->ls_req);
 131         ospf_lsdb_cleanup(&nbr->ls_rxmt);
 132
 133         /* Clear last send packet. */
 134         if (nbr->last_send)
 135                 ospf_packet_free(nbr->last_send);
 136
 137         if (nbr->nbr_nbma) {
 138                 nbr->nbr_nbma->nbr = NULL;
 139                 nbr->nbr_nbma = NULL;
 140         }
 141
 142         /* Cancel all timers. */
 143         OSPF_NSM_TIMER_OFF(nbr->t_inactivity);
 144         OSPF_NSM_TIMER_OFF(nbr->t_db_desc);
 145         OSPF_NSM_TIMER_OFF(nbr->t_ls_req);
 146         OSPF_NSM_TIMER_OFF(nbr->t_ls_upd);
 147
 148         /* Cancel all events. */ /* Thread lookup cost would be negligible. */
 149         thread_cancel_event(master, nbr);
 150
 151         bfd_sess_free(&nbr->bfd_session);
 152
 153         OSPF_NSM_TIMER_OFF(nbr->gr_helper_info.t_grace_timer);
 154
 155         nbr->oi = NULL;
 156         XFREE(MTYPE_OSPF_NEIGHBOR, nbr);
 157 }
 158
 159 /* Delete specified OSPF neighbor from interface. */
 160 void ospf_nbr_delete(struct ospf_neighbor *nbr)
 161 {
 162         struct ospf_interface *oi;
 163         struct route_node *rn;
 164         struct prefix p;
 165
 166         oi = nbr->oi;
 167
 168         /* get appropriate prefix 'key' */
 169         ospf_nbr_key(oi, nbr, &p);
 170
 171         rn = route_node_lookup(oi->nbrs, &p);
 172         if (rn) {
 173                 /* If lookup for a NBR succeeds, the leaf route_node could
 174                  * only exist because there is (or was) a nbr there.
 175                  * If the nbr was deleted, the leaf route_node should have
 176                  * lost its last refcount too, and be deleted.
 177                  * Therefore a looked-up leaf route_node in nbrs table
 178                  * should never have NULL info.
 179                  */
 180                 assert(rn->info);
 181
 182                 if (rn->info) {
 183                         rn->info = NULL;
 184                         route_unlock_node(rn);
 185                 } else
 186                         zlog_info("Can't find neighbor %pI4 in the interface %s",
 187                                   &nbr->src, IF_NAME(oi));
 188
 189                 route_unlock_node(rn);
 190         } else {
 191                 /*
 192                  * This neighbor was not found, but before we move on and
 193                  * free the neighbor structre, make sure that it was not
 194                  * indexed incorrectly and ended up in the "worng" place
 195                  */
 196
 197                 /* Reverse the lookup rules */
 198                 if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 199                     || oi->type == OSPF_IFTYPE_POINTOPOINT)
 200                         p.u.prefix4 = nbr->src;
 201                 else
 202                         p.u.prefix4 = nbr->router_id;
 203
 204                 rn = route_node_lookup(oi->nbrs, &p);
 205                 if (rn) {
 206                         /* We found the neighbor!
 207                          * Now make sure it is not the exact same neighbor
 208                          * structure that we are about to free
 209                          */
 210                         if (nbr == rn->info) {
 211                                 /* Same neighbor, drop the reference to it */
 212                                 rn->info = NULL;
 213                                 route_unlock_node(rn);
 214                         }
 215                         route_unlock_node(rn);
 216                 }
 217         }
 218
 219         /* Free ospf_neighbor structure. */
 220         ospf_nbr_free(nbr);
 221 }
 222
 223 /* Check myself is in the neighbor list. */
 224 int ospf_nbr_bidirectional(struct in_addr *router_id, struct in_addr *neighbors,
 225                            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 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 ospf_nbr_add_self(struct ospf_interface *oi, struct in_addr router_id)
 251 {
 252         struct prefix p;
 253         struct route_node *rn;
 254
 255         if (!oi->nbr_self)
 256                 oi->nbr_self = ospf_nbr_new(oi);
 257
 258         /* Initial state */
 259         oi->nbr_self->address = *oi->address;
 260         oi->nbr_self->priority = OSPF_IF_PARAM(oi, priority);
 261         oi->nbr_self->router_id = router_id;
 262         oi->nbr_self->src = oi->address->u.prefix4;
 263         oi->nbr_self->state = NSM_TwoWay;
 264
 265         switch (oi->area->external_routing) {
 266         case OSPF_AREA_DEFAULT:
 267                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 268                 break;
 269         case OSPF_AREA_STUB:
 270                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 271                 break;
 272         case OSPF_AREA_NSSA:
 273                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 274                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_NP);
 275                 break;
 276         }
 277
 278         /* Add nbr_self to nbrs table */
 279         ospf_nbr_key(oi, oi->nbr_self, &p);
 280
 281         rn = route_node_get(oi->nbrs, &p);
 282         if (rn->info) {
 283                 /* There is already pseudo neighbor. */
 284                 if (IS_DEBUG_OSPF_EVENT)
 285                         zlog_debug(
 286                                 "router_id %pI4 already present in neighbor table. node refcount %u",
 287                                 &router_id, route_node_get_lock_count(rn));
 288                 route_unlock_node(rn);
 289         } else
 290                 rn->info = oi->nbr_self;
 291 }
 292
 293 /* Get neighbor count by status.
 294    Specify status = 0, get all neighbor other than myself. */
 295 int ospf_nbr_count(struct ospf_interface *oi, int state)
 296 {
 297         struct ospf_neighbor *nbr;
 298         struct route_node *rn;
 299         int count = 0;
 300
 301         for (rn = route_top(oi->nbrs); rn; rn = route_next(rn))
 302                 if ((nbr = rn->info))
 303                         if (!IPV4_ADDR_SAME(&nbr->router_id,
 304                                             &oi->ospf->router_id))
 305                                 if (state == 0 || nbr->state == state)
 306                                         count++;
 307
 308         return count;
 309 }
 310
 311 int ospf_nbr_count_opaque_capable(struct ospf_interface *oi)
 312 {
 313         struct ospf_neighbor *nbr;
 314         struct route_node *rn;
 315         int count = 0;
 316
 317         for (rn = route_top(oi->nbrs); rn; rn = route_next(rn))
 318                 if ((nbr = rn->info))
 319                         if (!IPV4_ADDR_SAME(&nbr->router_id,
 320                                             &oi->ospf->router_id))
 321                                 if (nbr->state == NSM_Full)
 322                                         if (CHECK_FLAG(nbr->options,
 323                                                        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 *ospf_nbr_lookup_by_addr(struct route_table *nbrs,
 334                                               struct in_addr *addr)
 335 {
 336         struct prefix p;
 337         struct route_node *rn;
 338         struct ospf_neighbor *nbr;
 339
 340         p.family = AF_INET;
 341         p.prefixlen = IPV4_MAX_BITLEN;
 342         p.u.prefix4 = *addr;
 343
 344         rn = route_node_lookup(nbrs, &p);
 345         if (!rn)
 346                 return NULL;
 347
 348         /* See comment in ospf_nbr_delete */
 349         assert(rn->info);
 350
 351         if (rn->info == NULL) {
 352                 route_unlock_node(rn);
 353                 return NULL;
 354         }
 355
 356         nbr = (struct ospf_neighbor *)rn->info;
 357         route_unlock_node(rn);
 358
 359         return nbr;
 360 }
 361
 362 struct ospf_neighbor *ospf_nbr_lookup_by_routerid(struct route_table *nbrs,
 363                                                   struct in_addr *id)
 364 {
 365         struct route_node *rn;
 366         struct ospf_neighbor *nbr;
 367
 368         for (rn = route_top(nbrs); rn; rn = route_next(rn))
 369                 if ((nbr = rn->info) != NULL)
 370                         if (IPV4_ADDR_SAME(&nbr->router_id, id)) {
 371                                 route_unlock_node(rn);
 372                                 return nbr;
 373                         }
 374
 375         return NULL;
 376 }
 377
 378 void ospf_renegotiate_optional_capabilities(struct ospf *top)
 379 {
 380         struct listnode *node;
 381         struct ospf_interface *oi;
 382         struct route_table *nbrs;
 383         struct route_node *rn;
 384         struct ospf_neighbor *nbr;
 385
 386         /* At first, flush self-originated LSAs from routing domain. */
 387         ospf_flush_self_originated_lsas_now(top);
 388
 389         /* Revert all neighbor status to ExStart. */
 390         for (ALL_LIST_ELEMENTS_RO(top->oiflist, node, oi)) {
 391                 if ((nbrs = oi->nbrs) == NULL)
 392                         continue;
 393
 394                 for (rn = route_top(nbrs); rn; rn = route_next(rn)) {
 395                         if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
 396                                 continue;
 397
 398                         if (nbr->state < NSM_ExStart)
 399                                 continue;
 400
 401                         if (IS_DEBUG_OSPF_EVENT)
 402                                 zlog_debug(
 403                                         "Renegotiate optional capabilities with neighbor(%pI4)",
 404                                         &nbr->router_id);
 405
 406                         OSPF_NSM_EVENT_SCHEDULE(nbr, NSM_SeqNumberMismatch);
 407                 }
 408         }
 409
 410         return;
 411 }
 412
 413
 414 struct ospf_neighbor *ospf_nbr_lookup(struct ospf_interface *oi, struct ip *iph,
 415                                       struct ospf_header *ospfh)
 416 {
 417         struct in_addr srcaddr = iph->ip_src;
 418
 419         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 420             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 421                 return (ospf_nbr_lookup_by_routerid(oi->nbrs,
 422                                                     &ospfh->router_id));
 423         else
 424                 return (ospf_nbr_lookup_by_addr(oi->nbrs, &srcaddr));
 425 }
 426
 427 static struct ospf_neighbor *ospf_nbr_add(struct ospf_interface *oi,
 428                                           struct ospf_header *ospfh,
 429                                           struct prefix *p)
 430 {
 431         struct ospf_neighbor *nbr;
 432
 433         nbr = ospf_nbr_new(oi);
 434         nbr->state = NSM_Down;
 435         nbr->src = p->u.prefix4;
 436         memcpy(&nbr->address, p, sizeof(struct prefix));
 437
 438         nbr->nbr_nbma = NULL;
 439         if (oi->type == OSPF_IFTYPE_NBMA) {
 440                 struct ospf_nbr_nbma *nbr_nbma;
 441                 struct listnode *node;
 442
 443                 for (ALL_LIST_ELEMENTS_RO(oi->nbr_nbma, node, nbr_nbma)) {
 444                         if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src)) {
 445                                 nbr_nbma->nbr = nbr;
 446                                 nbr->nbr_nbma = nbr_nbma;
 447
 448                                 if (nbr_nbma->t_poll)
 449                                         OSPF_POLL_TIMER_OFF(nbr_nbma->t_poll);
 450
 451                                 nbr->state_change = nbr_nbma->state_change + 1;
 452                         }
 453                 }
 454         }
 455
 456         /* New nbr, save the crypto sequence number if necessary */
 457         if (ntohs(ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
 458                 nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
 459
 460         /* Configure BFD if interface has it. */
 461         ospf_neighbor_bfd_apply(nbr);
 462
 463         if (IS_DEBUG_OSPF_EVENT)
 464                 zlog_debug("NSM[%s:%pI4]: start", IF_NAME(oi),
 465                            &nbr->router_id);
 466
 467         return nbr;
 468 }
 469
 470 struct ospf_neighbor *ospf_nbr_get(struct ospf_interface *oi,
 471                                    struct ospf_header *ospfh, struct ip *iph,
 472                                    struct prefix *p)
 473 {
 474         struct route_node *rn;
 475         struct prefix key;
 476         struct ospf_neighbor *nbr;
 477
 478         key.family = AF_INET;
 479         key.prefixlen = IPV4_MAX_BITLEN;
 480
 481         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 482             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 483                 key.u.prefix4 = ospfh->router_id; /* index vlink and ptp nbrs by
 484                                                      router-id */
 485         else
 486                 key.u.prefix4 = iph->ip_src;
 487
 488         rn = route_node_get(oi->nbrs, &key);
 489         if (rn->info) {
 490                 route_unlock_node(rn);
 491                 nbr = rn->info;
 492
 493                 if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt) {
 494                         nbr->src = iph->ip_src;
 495                         memcpy(&nbr->address, p, sizeof(struct prefix));
 496                 }
 497         } else {
 498                 rn->info = nbr = ospf_nbr_add(oi, ospfh, p);
 499         }
 500
 501         nbr->router_id = ospfh->router_id;
 502
 503         return nbr;
 504 }