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 #include "ospfd/ospf_gr_helper.h"
  47
  48 /* Fill in the the 'key' as appropriate to retrieve the entry for nbr
  49  * from the ospf_interface's nbrs table. Indexed by interface address
  50  * for all cases except Virtual-link and PointToPoint interfaces, where
  51  * neighbours are indexed by router-ID instead.
  52  */
  53 static void 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 *ospf_nbr_new(struct ospf_interface *oi)
  69 {
  70         struct ospf_neighbor *nbr;
  71
  72         /* Allcate new neighbor. */
  73         nbr = XCALLOC(MTYPE_OSPF_NEIGHBOR, 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         ospf_bfd_info_nbr_create(oi, nbr);
 103
 104         /* Initialize GR Helper info*/
 105         nbr->gr_helper_info.recvd_grace_period = 0;
 106         nbr->gr_helper_info.actual_grace_period = 0;
 107         nbr->gr_helper_info.gr_helper_status = OSPF_GR_NOT_HELPER;
 108         nbr->gr_helper_info.helper_exit_reason = OSPF_GR_HELPER_EXIT_NONE;
 109         nbr->gr_helper_info.gr_restart_reason = OSPF_GR_UNKNOWN_RESTART;
 110
 111         return nbr;
 112 }
 113
 114 void ospf_nbr_free(struct ospf_neighbor *nbr)
 115 {
 116         /* Free DB summary list. */
 117         if (ospf_db_summary_count(nbr))
 118                 ospf_db_summary_clear(nbr);
 119         /* ospf_db_summary_delete_all (nbr); */
 120
 121         /* Free ls request list. */
 122         if (ospf_ls_request_count(nbr))
 123                 ospf_ls_request_delete_all(nbr);
 124
 125         /* Free retransmit list. */
 126         if (ospf_ls_retransmit_count(nbr))
 127                 ospf_ls_retransmit_clear(nbr);
 128
 129         /* Cleanup LSDBs. */
 130         ospf_lsdb_cleanup(&nbr->db_sum);
 131         ospf_lsdb_cleanup(&nbr->ls_req);
 132         ospf_lsdb_cleanup(&nbr->ls_rxmt);
 133
 134         /* Clear last send packet. */
 135         if (nbr->last_send)
 136                 ospf_packet_free(nbr->last_send);
 137
 138         if (nbr->nbr_nbma) {
 139                 nbr->nbr_nbma->nbr = NULL;
 140                 nbr->nbr_nbma = NULL;
 141         }
 142
 143         /* Cancel all timers. */
 144         OSPF_NSM_TIMER_OFF(nbr->t_inactivity);
 145         OSPF_NSM_TIMER_OFF(nbr->t_db_desc);
 146         OSPF_NSM_TIMER_OFF(nbr->t_ls_req);
 147         OSPF_NSM_TIMER_OFF(nbr->t_ls_upd);
 148
 149         /* Cancel all events. */ /* Thread lookup cost would be negligible. */
 150         thread_cancel_event(master, nbr);
 151
 152         ospf_bfd_info_free(&nbr->bfd_info);
 153
 154         OSPF_NSM_TIMER_OFF(nbr->gr_helper_info.t_grace_timer);
 155
 156         nbr->oi = NULL;
 157         XFREE(MTYPE_OSPF_NEIGHBOR, nbr);
 158 }
 159
 160 /* Delete specified OSPF neighbor from interface. */
 161 void ospf_nbr_delete(struct ospf_neighbor *nbr)
 162 {
 163         struct ospf_interface *oi;
 164         struct route_node *rn;
 165         struct prefix p;
 166
 167         oi = nbr->oi;
 168
 169         /* get appropriate prefix 'key' */
 170         ospf_nbr_key(oi, nbr, &p);
 171
 172         rn = route_node_lookup(oi->nbrs, &p);
 173         if (rn) {
 174                 /* If lookup for a NBR succeeds, the leaf route_node could
 175                  * only exist because there is (or was) a nbr there.
 176                  * If the nbr was deleted, the leaf route_node should have
 177                  * lost its last refcount too, and be deleted.
 178                  * Therefore a looked-up leaf route_node in nbrs table
 179                  * should never have NULL info.
 180                  */
 181                 assert(rn->info);
 182
 183                 if (rn->info) {
 184                         rn->info = NULL;
 185                         route_unlock_node(rn);
 186                 } else
 187                         zlog_info("Can't find neighbor %pI4 in the interface %s",
 188                                   &nbr->src, IF_NAME(oi));
 189
 190                 route_unlock_node(rn);
 191         } else {
 192                 /*
 193                  * This neighbor was not found, but before we move on and
 194                  * free the neighbor structre, make sure that it was not
 195                  * indexed incorrectly and ended up in the "worng" place
 196                  */
 197
 198                 /* Reverse the lookup rules */
 199                 if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 200                     || oi->type == OSPF_IFTYPE_POINTOPOINT)
 201                         p.u.prefix4 = nbr->src;
 202                 else
 203                         p.u.prefix4 = nbr->router_id;
 204
 205                 rn = route_node_lookup(oi->nbrs, &p);
 206                 if (rn) {
 207                         /* We found the neighbor!
 208                          * Now make sure it is not the exact same neighbor
 209                          * structure that we are about to free
 210                          */
 211                         if (nbr == rn->info) {
 212                                 /* Same neighbor, drop the reference to it */
 213                                 rn->info = NULL;
 214                                 route_unlock_node(rn);
 215                         }
 216                         route_unlock_node(rn);
 217                 }
 218         }
 219
 220         /* Free ospf_neighbor structure. */
 221         ospf_nbr_free(nbr);
 222 }
 223
 224 /* Check myself is in the neighbor list. */
 225 int ospf_nbr_bidirectional(struct in_addr *router_id, struct in_addr *neighbors,
 226                            int size)
 227 {
 228         int i;
 229         int max;
 230
 231         max = size / sizeof(struct in_addr);
 232
 233         for (i = 0; i < max; i++)
 234                 if (IPV4_ADDR_SAME(router_id, &neighbors[i]))
 235                         return 1;
 236
 237         return 0;
 238 }
 239
 240 /* reset nbr_self */
 241 void ospf_nbr_self_reset(struct ospf_interface *oi, struct in_addr router_id)
 242 {
 243         if (oi->nbr_self)
 244                 ospf_nbr_delete(oi->nbr_self);
 245
 246         oi->nbr_self = ospf_nbr_new(oi);
 247         ospf_nbr_add_self(oi, router_id);
 248 }
 249
 250 /* Add self to nbr list. */
 251 void 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         case OSPF_AREA_DEFAULT:
 268                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 269                 break;
 270         case OSPF_AREA_STUB:
 271                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 272                 break;
 273         case OSPF_AREA_NSSA:
 274                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 275                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_NP);
 276                 break;
 277         }
 278
 279         /* Add nbr_self to nbrs table */
 280         ospf_nbr_key(oi, oi->nbr_self, &p);
 281
 282         rn = route_node_get(oi->nbrs, &p);
 283         if (rn->info) {
 284                 /* There is already pseudo neighbor. */
 285                 if (IS_DEBUG_OSPF_EVENT)
 286                         zlog_debug(
 287                                 "router_id %pI4 already present in neighbor table. node refcount %u",
 288                                 &router_id, route_node_get_lock_count(rn));
 289                 route_unlock_node(rn);
 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 ospf_nbr_count(struct ospf_interface *oi, int state)
 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 (state == 0 || nbr->state == state)
 307                                         count++;
 308
 309         return count;
 310 }
 311
 312 int ospf_nbr_count_opaque_capable(struct ospf_interface *oi)
 313 {
 314         struct ospf_neighbor *nbr;
 315         struct route_node *rn;
 316         int count = 0;
 317
 318         for (rn = route_top(oi->nbrs); rn; rn = route_next(rn))
 319                 if ((nbr = rn->info))
 320                         if (!IPV4_ADDR_SAME(&nbr->router_id,
 321                                             &oi->ospf->router_id))
 322                                 if (nbr->state == NSM_Full)
 323                                         if (CHECK_FLAG(nbr->options,
 324                                                        OSPF_OPTION_O))
 325                                                 count++;
 326
 327         return count;
 328 }
 329
 330 /* lookup nbr by address - use this only if you know you must
 331  * otherwise use the ospf_nbr_lookup() wrapper, which deals
 332  * with virtual link and PointToPoint neighbours
 333  */
 334 struct ospf_neighbor *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                 route_unlock_node(rn);
 354                 return NULL;
 355         }
 356
 357         nbr = (struct ospf_neighbor *)rn->info;
 358         route_unlock_node(rn);
 359
 360         return nbr;
 361 }
 362
 363 struct ospf_neighbor *ospf_nbr_lookup_by_routerid(struct route_table *nbrs,
 364                                                   struct in_addr *id)
 365 {
 366         struct route_node *rn;
 367         struct ospf_neighbor *nbr;
 368
 369         for (rn = route_top(nbrs); rn; rn = route_next(rn))
 370                 if ((nbr = rn->info) != NULL)
 371                         if (IPV4_ADDR_SAME(&nbr->router_id, id)) {
 372                                 route_unlock_node(rn);
 373                                 return nbr;
 374                         }
 375
 376         return NULL;
 377 }
 378
 379 void ospf_renegotiate_optional_capabilities(struct ospf *top)
 380 {
 381         struct listnode *node;
 382         struct ospf_interface *oi;
 383         struct route_table *nbrs;
 384         struct route_node *rn;
 385         struct ospf_neighbor *nbr;
 386
 387         /* At first, flush self-originated LSAs from routing domain. */
 388         ospf_flush_self_originated_lsas_now(top);
 389
 390         /* Revert all neighbor status to ExStart. */
 391         for (ALL_LIST_ELEMENTS_RO(top->oiflist, node, oi)) {
 392                 if ((nbrs = oi->nbrs) == NULL)
 393                         continue;
 394
 395                 for (rn = route_top(nbrs); rn; rn = route_next(rn)) {
 396                         if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
 397                                 continue;
 398
 399                         if (nbr->state < NSM_ExStart)
 400                                 continue;
 401
 402                         if (IS_DEBUG_OSPF_EVENT)
 403                                 zlog_debug(
 404                                         "Renegotiate optional capabilities with neighbor(%pI4)",
 405                                         &nbr->router_id);
 406
 407                         OSPF_NSM_EVENT_SCHEDULE(nbr, NSM_SeqNumberMismatch);
 408                 }
 409         }
 410
 411         return;
 412 }
 413
 414
 415 struct ospf_neighbor *ospf_nbr_lookup(struct ospf_interface *oi, struct ip *iph,
 416                                       struct ospf_header *ospfh)
 417 {
 418         struct in_addr srcaddr = iph->ip_src;
 419
 420         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 421             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 422                 return (ospf_nbr_lookup_by_routerid(oi->nbrs,
 423                                                     &ospfh->router_id));
 424         else
 425                 return (ospf_nbr_lookup_by_addr(oi->nbrs, &srcaddr));
 426 }
 427
 428 static struct ospf_neighbor *ospf_nbr_add(struct ospf_interface *oi,
 429                                           struct ospf_header *ospfh,
 430                                           struct prefix *p)
 431 {
 432         struct ospf_neighbor *nbr;
 433
 434         nbr = ospf_nbr_new(oi);
 435         nbr->state = NSM_Down;
 436         nbr->src = p->u.prefix4;
 437         memcpy(&nbr->address, p, sizeof(struct prefix));
 438
 439         nbr->nbr_nbma = NULL;
 440         if (oi->type == OSPF_IFTYPE_NBMA) {
 441                 struct ospf_nbr_nbma *nbr_nbma;
 442                 struct listnode *node;
 443
 444                 for (ALL_LIST_ELEMENTS_RO(oi->nbr_nbma, node, nbr_nbma)) {
 445                         if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src)) {
 446                                 nbr_nbma->nbr = nbr;
 447                                 nbr->nbr_nbma = nbr_nbma;
 448
 449                                 if (nbr_nbma->t_poll)
 450                                         OSPF_POLL_TIMER_OFF(nbr_nbma->t_poll);
 451
 452                                 nbr->state_change = nbr_nbma->state_change + 1;
 453                         }
 454                 }
 455         }
 456
 457         /* New nbr, save the crypto sequence number if necessary */
 458         if (ntohs(ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
 459                 nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
 460
 461         if (IS_DEBUG_OSPF_EVENT)
 462                 zlog_debug("NSM[%s:%pI4]: start", IF_NAME(oi),
 463                            &nbr->router_id);
 464
 465         return nbr;
 466 }
 467
 468 struct ospf_neighbor *ospf_nbr_get(struct ospf_interface *oi,
 469                                    struct ospf_header *ospfh, struct ip *iph,
 470                                    struct prefix *p)
 471 {
 472         struct route_node *rn;
 473         struct prefix key;
 474         struct ospf_neighbor *nbr;
 475
 476         key.family = AF_INET;
 477         key.prefixlen = IPV4_MAX_BITLEN;
 478
 479         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 480             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 481                 key.u.prefix4 = ospfh->router_id; /* index vlink and ptp nbrs by
 482                                                      router-id */
 483         else
 484                 key.u.prefix4 = iph->ip_src;
 485
 486         rn = route_node_get(oi->nbrs, &key);
 487         if (rn->info) {
 488                 route_unlock_node(rn);
 489                 nbr = rn->info;
 490
 491                 if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt) {
 492                         nbr->src = iph->ip_src;
 493                         memcpy(&nbr->address, p, sizeof(struct prefix));
 494                 }
 495         } else {
 496                 rn->info = nbr = ospf_nbr_add(oi, ospfh, p);
 497         }
 498
 499         nbr->router_id = ospfh->router_id;
 500
 501         return nbr;
 502 }