ospfd/ospf_neighbor.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * OSPF Neighbor functions.
   4  * Copyright (C) 1999, 2000 Toshiaki Takada
   5  */
   6
   7 #include <zebra.h>
   8
   9 #include "lib/bfd.h"
  10 #include "linklist.h"
  11 #include "prefix.h"
  12 #include "memory.h"
  13 #include "command.h"
  14 #include "event.h"
  15 #include "stream.h"
  16 #include "table.h"
  17 #include "log.h"
  18 #include "json.h"
  19
  20 #include "ospfd/ospfd.h"
  21 #include "ospfd/ospf_interface.h"
  22 #include "ospfd/ospf_asbr.h"
  23 #include "ospfd/ospf_lsa.h"
  24 #include "ospfd/ospf_lsdb.h"
  25 #include "ospfd/ospf_neighbor.h"
  26 #include "ospfd/ospf_nsm.h"
  27 #include "ospfd/ospf_packet.h"
  28 #include "ospfd/ospf_network.h"
  29 #include "ospfd/ospf_flood.h"
  30 #include "ospfd/ospf_dump.h"
  31 #include "ospfd/ospf_bfd.h"
  32 #include "ospfd/ospf_gr.h"
  33
  34 /* Fill in the the 'key' as appropriate to retrieve the entry for nbr
  35  * from the ospf_interface's nbrs table. Indexed by interface address
  36  * for all cases except Virtual-link and PointToPoint interfaces, where
  37  * neighbours are indexed by router-ID instead.
  38  */
  39 static void ospf_nbr_key(struct ospf_interface *oi, struct ospf_neighbor *nbr,
  40                          struct prefix *key)
  41 {
  42         key->family = AF_INET;
  43         key->prefixlen = IPV4_MAX_BITLEN;
  44
  45         /* vlinks are indexed by router-id */
  46         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
  47             || oi->type == OSPF_IFTYPE_POINTOPOINT)
  48                 key->u.prefix4 = nbr->router_id;
  49         else
  50                 key->u.prefix4 = nbr->src;
  51         return;
  52 }
  53
  54 struct ospf_neighbor *ospf_nbr_new(struct ospf_interface *oi)
  55 {
  56         struct ospf_neighbor *nbr;
  57
  58         /* Allcate new neighbor. */
  59         nbr = XCALLOC(MTYPE_OSPF_NEIGHBOR, sizeof(struct ospf_neighbor));
  60
  61         /* Relate neighbor to the interface. */
  62         nbr->oi = oi;
  63
  64         /* Set default values. */
  65         nbr->state = NSM_Down;
  66
  67         /* Set inheritance values. */
  68         nbr->v_inactivity = OSPF_IF_PARAM(oi, v_wait);
  69         nbr->v_db_desc = OSPF_IF_PARAM(oi, retransmit_interval);
  70         nbr->v_ls_req = OSPF_IF_PARAM(oi, retransmit_interval);
  71         nbr->v_ls_upd = OSPF_IF_PARAM(oi, retransmit_interval);
  72         nbr->priority = -1;
  73
  74         /* DD flags. */
  75         nbr->dd_flags = OSPF_DD_FLAG_MS | OSPF_DD_FLAG_M | OSPF_DD_FLAG_I;
  76
  77         /* Last received and sent DD. */
  78         nbr->last_send = NULL;
  79
  80         nbr->nbr_nbma = NULL;
  81
  82         ospf_lsdb_init(&nbr->db_sum);
  83         ospf_lsdb_init(&nbr->ls_rxmt);
  84         ospf_lsdb_init(&nbr->ls_req);
  85
  86         nbr->crypt_seqnum = 0;
  87
  88         /* Initialize GR Helper info*/
  89         nbr->gr_helper_info.recvd_grace_period = 0;
  90         nbr->gr_helper_info.actual_grace_period = 0;
  91         nbr->gr_helper_info.gr_helper_status = OSPF_GR_NOT_HELPER;
  92         nbr->gr_helper_info.helper_exit_reason = OSPF_GR_HELPER_EXIT_NONE;
  93         nbr->gr_helper_info.gr_restart_reason = OSPF_GR_UNKNOWN_RESTART;
  94
  95         return nbr;
  96 }
  97
  98 void ospf_nbr_free(struct ospf_neighbor *nbr)
  99 {
 100         /* Free DB summary list. */
 101         if (ospf_db_summary_count(nbr))
 102                 ospf_db_summary_clear(nbr);
 103         /* ospf_db_summary_delete_all (nbr); */
 104
 105         /* Free ls request list. */
 106         if (ospf_ls_request_count(nbr))
 107                 ospf_ls_request_delete_all(nbr);
 108
 109         /* Free retransmit list. */
 110         if (ospf_ls_retransmit_count(nbr))
 111                 ospf_ls_retransmit_clear(nbr);
 112
 113         /* Cleanup LSDBs. */
 114         ospf_lsdb_cleanup(&nbr->db_sum);
 115         ospf_lsdb_cleanup(&nbr->ls_req);
 116         ospf_lsdb_cleanup(&nbr->ls_rxmt);
 117
 118         /* Clear last send packet. */
 119         if (nbr->last_send)
 120                 ospf_packet_free(nbr->last_send);
 121
 122         if (nbr->nbr_nbma) {
 123                 nbr->nbr_nbma->nbr = NULL;
 124                 nbr->nbr_nbma = NULL;
 125         }
 126
 127         /* Cancel all timers. */
 128         THREAD_OFF(nbr->t_inactivity);
 129         THREAD_OFF(nbr->t_db_desc);
 130         THREAD_OFF(nbr->t_ls_req);
 131         THREAD_OFF(nbr->t_ls_upd);
 132
 133         /* Cancel all events. */ /* Thread lookup cost would be negligible. */
 134         event_cancel_event(master, nbr);
 135
 136         bfd_sess_free(&nbr->bfd_session);
 137
 138         THREAD_OFF(nbr->gr_helper_info.t_grace_timer);
 139
 140         nbr->oi = NULL;
 141         XFREE(MTYPE_OSPF_NEIGHBOR, nbr);
 142 }
 143
 144 /* Delete specified OSPF neighbor from interface. */
 145 void ospf_nbr_delete(struct ospf_neighbor *nbr)
 146 {
 147         struct ospf_interface *oi;
 148         struct route_node *rn;
 149         struct prefix p;
 150
 151         oi = nbr->oi;
 152
 153         /* get appropriate prefix 'key' */
 154         ospf_nbr_key(oi, nbr, &p);
 155
 156         rn = route_node_lookup(oi->nbrs, &p);
 157         if (rn) {
 158                 /* If lookup for a NBR succeeds, the leaf route_node could
 159                  * only exist because there is (or was) a nbr there.
 160                  * If the nbr was deleted, the leaf route_node should have
 161                  * lost its last refcount too, and be deleted.
 162                  * Therefore a looked-up leaf route_node in nbrs table
 163                  * should never have NULL info.
 164                  */
 165                 assert(rn->info);
 166
 167                 if (rn->info) {
 168                         rn->info = NULL;
 169                         route_unlock_node(rn);
 170                 } else
 171                         zlog_info("Can't find neighbor %pI4 in the interface %s",
 172                                   &nbr->src, IF_NAME(oi));
 173
 174                 route_unlock_node(rn);
 175         } else {
 176                 /*
 177                  * This neighbor was not found, but before we move on and
 178                  * free the neighbor structre, make sure that it was not
 179                  * indexed incorrectly and ended up in the "worng" place
 180                  */
 181
 182                 /* Reverse the lookup rules */
 183                 if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 184                     || oi->type == OSPF_IFTYPE_POINTOPOINT)
 185                         p.u.prefix4 = nbr->src;
 186                 else
 187                         p.u.prefix4 = nbr->router_id;
 188
 189                 rn = route_node_lookup(oi->nbrs, &p);
 190                 if (rn) {
 191                         /* We found the neighbor!
 192                          * Now make sure it is not the exact same neighbor
 193                          * structure that we are about to free
 194                          */
 195                         if (nbr == rn->info) {
 196                                 /* Same neighbor, drop the reference to it */
 197                                 rn->info = NULL;
 198                                 route_unlock_node(rn);
 199                         }
 200                         route_unlock_node(rn);
 201                 }
 202         }
 203
 204         /* Free ospf_neighbor structure. */
 205         ospf_nbr_free(nbr);
 206 }
 207
 208 /* Check myself is in the neighbor list. */
 209 int ospf_nbr_bidirectional(struct in_addr *router_id, struct in_addr *neighbors,
 210                            int size)
 211 {
 212         int i;
 213         int max;
 214
 215         max = size / sizeof(struct in_addr);
 216
 217         for (i = 0; i < max; i++)
 218                 if (IPV4_ADDR_SAME(router_id, &neighbors[i]))
 219                         return 1;
 220
 221         return 0;
 222 }
 223
 224 /* reset nbr_self */
 225 void ospf_nbr_self_reset(struct ospf_interface *oi, struct in_addr router_id)
 226 {
 227         if (oi->nbr_self)
 228                 ospf_nbr_delete(oi->nbr_self);
 229
 230         oi->nbr_self = ospf_nbr_new(oi);
 231         ospf_nbr_add_self(oi, router_id);
 232 }
 233
 234 /* Add self to nbr list. */
 235 void ospf_nbr_add_self(struct ospf_interface *oi, struct in_addr router_id)
 236 {
 237         struct prefix p;
 238         struct route_node *rn;
 239
 240         if (!oi->nbr_self)
 241                 oi->nbr_self = ospf_nbr_new(oi);
 242
 243         /* Initial state */
 244         oi->nbr_self->address = *oi->address;
 245         oi->nbr_self->priority = OSPF_IF_PARAM(oi, priority);
 246         oi->nbr_self->router_id = router_id;
 247         oi->nbr_self->src = oi->address->u.prefix4;
 248         oi->nbr_self->state = NSM_TwoWay;
 249
 250         switch (oi->area->external_routing) {
 251         case OSPF_AREA_DEFAULT:
 252                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 253                 break;
 254         case OSPF_AREA_STUB:
 255                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 256                 break;
 257         case OSPF_AREA_NSSA:
 258                 UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
 259                 SET_FLAG(oi->nbr_self->options, OSPF_OPTION_NP);
 260                 break;
 261         }
 262
 263         /* Add nbr_self to nbrs table */
 264         ospf_nbr_key(oi, oi->nbr_self, &p);
 265
 266         rn = route_node_get(oi->nbrs, &p);
 267         if (rn->info) {
 268                 /* There is already pseudo neighbor. */
 269                 if (IS_DEBUG_OSPF_EVENT)
 270                         zlog_debug(
 271                                 "router_id %pI4 already present in neighbor table. node refcount %u",
 272                                 &router_id, route_node_get_lock_count(rn));
 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         uint8_t shutdown_save = top->inst_shutdown;
 371
 372         /* At first, flush self-originated LSAs from routing domain. */
 373         ospf_flush_self_originated_lsas_now(top);
 374
 375         /* ospf_flush_self_originated_lsas_now is primarily intended for shut
 376          * down scenarios. Reset the inst_shutdown flag that it sets. We are
 377          * just changing configuration, and the flag can change the scheduling
 378          * of when maxage LSAs are sent. */
 379         top->inst_shutdown = shutdown_save;
 380
 381         /* Revert all neighbor status to ExStart. */
 382         for (ALL_LIST_ELEMENTS_RO(top->oiflist, node, oi)) {
 383                 if ((nbrs = oi->nbrs) == NULL)
 384                         continue;
 385
 386                 for (rn = route_top(nbrs); rn; rn = route_next(rn)) {
 387                         if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
 388                                 continue;
 389
 390                         if (nbr->state < NSM_ExStart)
 391                                 continue;
 392
 393                         if (IS_DEBUG_OSPF_EVENT)
 394                                 zlog_debug(
 395                                         "Renegotiate optional capabilities with neighbor(%pI4)",
 396                                         &nbr->router_id);
 397
 398                         OSPF_NSM_EVENT_SCHEDULE(nbr, NSM_SeqNumberMismatch);
 399                 }
 400         }
 401
 402         /* Refresh/Re-originate external LSAs (Type-7 and Type-5).*/
 403         ospf_external_lsa_rid_change(top);
 404
 405         return;
 406 }
 407
 408
 409 struct ospf_neighbor *ospf_nbr_lookup(struct ospf_interface *oi, struct ip *iph,
 410                                       struct ospf_header *ospfh)
 411 {
 412         struct in_addr srcaddr = iph->ip_src;
 413
 414         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 415             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 416                 return (ospf_nbr_lookup_by_routerid(oi->nbrs,
 417                                                     &ospfh->router_id));
 418         else
 419                 return (ospf_nbr_lookup_by_addr(oi->nbrs, &srcaddr));
 420 }
 421
 422 static struct ospf_neighbor *ospf_nbr_add(struct ospf_interface *oi,
 423                                           struct ospf_header *ospfh,
 424                                           struct prefix *p)
 425 {
 426         struct ospf_neighbor *nbr;
 427
 428         nbr = ospf_nbr_new(oi);
 429         nbr->state = NSM_Down;
 430         nbr->src = p->u.prefix4;
 431         memcpy(&nbr->address, p, sizeof(struct prefix));
 432
 433         nbr->nbr_nbma = NULL;
 434         if (oi->type == OSPF_IFTYPE_NBMA) {
 435                 struct ospf_nbr_nbma *nbr_nbma;
 436                 struct listnode *node;
 437
 438                 for (ALL_LIST_ELEMENTS_RO(oi->nbr_nbma, node, nbr_nbma)) {
 439                         if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src)) {
 440                                 nbr_nbma->nbr = nbr;
 441                                 nbr->nbr_nbma = nbr_nbma;
 442
 443                                 if (nbr_nbma->t_poll)
 444                                         THREAD_OFF(nbr_nbma->t_poll);
 445
 446                                 nbr->state_change = nbr_nbma->state_change + 1;
 447                         }
 448                 }
 449         }
 450
 451         /* New nbr, save the crypto sequence number if necessary */
 452         if (ntohs(ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
 453                 nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
 454
 455         /* Configure BFD if interface has it. */
 456         ospf_neighbor_bfd_apply(nbr);
 457
 458         if (IS_DEBUG_OSPF_EVENT)
 459                 zlog_debug("NSM[%s:%pI4]: start", IF_NAME(oi),
 460                            &nbr->router_id);
 461
 462         return nbr;
 463 }
 464
 465 struct ospf_neighbor *ospf_nbr_get(struct ospf_interface *oi,
 466                                    struct ospf_header *ospfh, struct ip *iph,
 467                                    struct prefix *p)
 468 {
 469         struct route_node *rn;
 470         struct prefix key;
 471         struct ospf_neighbor *nbr;
 472
 473         key.family = AF_INET;
 474         key.prefixlen = IPV4_MAX_BITLEN;
 475
 476         if (oi->type == OSPF_IFTYPE_VIRTUALLINK
 477             || oi->type == OSPF_IFTYPE_POINTOPOINT)
 478                 key.u.prefix4 = ospfh->router_id; /* index vlink and ptp nbrs by
 479                                                      router-id */
 480         else
 481                 key.u.prefix4 = iph->ip_src;
 482
 483         rn = route_node_get(oi->nbrs, &key);
 484         if (rn->info) {
 485                 route_unlock_node(rn);
 486                 nbr = rn->info;
 487
 488                 if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt) {
 489                         nbr->src = iph->ip_src;
 490                         memcpy(&nbr->address, p, sizeof(struct prefix));
 491                 }
 492         } else {
 493                 rn->info = nbr = ospf_nbr_add(oi, ospfh, p);
 494         }
 495
 496         nbr->router_id = ospfh->router_id;
 497
 498         return nbr;
 499 }