ospfd/ospf_nsm.c

   1 /*
   2  * OSPF version 2  Neighbor State Machine
   3  * From RFC2328 [OSPF Version 2]
   4  * Copyright (C) 1999, 2000 Toshiaki Takada
   5  *
   6  * This file is part of GNU Zebra.
   7  *
   8  * GNU Zebra is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2, or (at your option) any
  11  * later version.
  12  *
  13  * GNU Zebra is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  20  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  21  * 02111-1307, USA.
  22  */
  23
  24 #include <zebra.h>
  25
  26 #include "thread.h"
  27 #include "memory.h"
  28 #include "hash.h"
  29 #include "linklist.h"
  30 #include "prefix.h"
  31 #include "if.h"
  32 #include "table.h"
  33 #include "stream.h"
  34 #include "table.h"
  35 #include "log.h"
  36
  37 #include "ospfd/ospfd.h"
  38 #include "ospfd/ospf_interface.h"
  39 #include "ospfd/ospf_ism.h"
  40 #include "ospfd/ospf_asbr.h"
  41 #include "ospfd/ospf_lsa.h"
  42 #include "ospfd/ospf_lsdb.h"
  43 #include "ospfd/ospf_neighbor.h"
  44 #include "ospfd/ospf_nsm.h"
  45 #include "ospfd/ospf_network.h"
  46 #include "ospfd/ospf_packet.h"
  47 #include "ospfd/ospf_dump.h"
  48 #include "ospfd/ospf_flood.h"
  49 #include "ospfd/ospf_abr.h"
  50
  51 void nsm_reset_nbr (struct ospf_neighbor *);
  52
  53 \f
  54 /* OSPF NSM Timer functions. */
  55 int
  56 ospf_inactivity_timer (struct thread *thread)
  57 {
  58   struct ospf_neighbor *nbr;
  59
  60   nbr = THREAD_ARG (thread);
  61   nbr->t_inactivity = NULL;
  62
  63   if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))
  64     zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: Timer (Inactivity timer expire)",
  65           IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));
  66
  67   OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_InactivityTimer);
  68
  69   return 0;
  70 }
  71
  72 int
  73 ospf_db_desc_timer (struct thread *thread)
  74 {
  75   struct ospf_interface *oi;
  76   struct ospf_neighbor *nbr;
  77
  78   nbr = THREAD_ARG (thread);
  79   nbr->t_db_desc = NULL;
  80
  81   oi = nbr->oi;
  82
  83   if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))
  84     zlog (NULL, LOG_INFO, "NSM[%s:%s]: Timer (DD Retransmit timer expire)",
  85           IF_NAME (nbr->oi), inet_ntoa (nbr->src));
  86
  87   /* resent last send DD packet. */
  88   assert (nbr->last_send);
  89   ospf_db_desc_resend (nbr);
  90
  91   /* DD Retransmit timer set. */
  92   OSPF_NSM_TIMER_ON (nbr->t_db_desc, ospf_db_desc_timer, nbr->v_db_desc);
  93
  94   return 0;
  95 }
  96
  97 /* Hook function called after ospf NSM event is occured. */
  98
  99 void
 100 nsm_timer_set (struct ospf_neighbor *nbr)
 101 {
 102   switch (nbr->state)
 103     {
 104     case NSM_Down:
 105       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 106       OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 107       break;
 108     case NSM_Attempt:
 109       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 110       OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 111       break;
 112     case NSM_Init:
 113       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 114       OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 115       break;
 116     case NSM_TwoWay:
 117       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 118       OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 119       break;
 120     case NSM_ExStart:
 121       OSPF_NSM_TIMER_ON (nbr->t_db_desc, ospf_db_desc_timer, nbr->v_db_desc);
 122       OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 123       break;
 124     case NSM_Exchange:
 125       OSPF_NSM_TIMER_ON (nbr->t_ls_upd, ospf_ls_upd_timer, nbr->v_ls_upd);
 126       if (!IS_SET_DD_MS (nbr->dd_flags))
 127         OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 128       break;
 129     case NSM_Loading:
 130       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 131       break;
 132     case NSM_Full:
 133       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 134       break;
 135     default:
 136       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 137       break;
 138     }
 139 }
 140
 141 \f
 142 /* OSPF NSM functions. */
 143 int
 144 nsm_ignore (struct ospf_neighbor *nbr)
 145 {
 146   if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 147     zlog (NULL, LOG_INFO, "NSM[%s:%s]: nsm_ignore called",
 148           IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));
 149
 150   return 0;
 151 }
 152
 153 int
 154 nsm_hello_received (struct ospf_neighbor *nbr)
 155 {
 156   /* Start or Restart Inactivity Timer. */
 157   OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
 158
 159   OSPF_NSM_TIMER_ON (nbr->t_inactivity, ospf_inactivity_timer,
 160                      nbr->v_inactivity);
 161
 162   if (nbr->oi->type == OSPF_IFTYPE_NBMA && nbr->nbr_nbma)
 163     OSPF_POLL_TIMER_OFF (nbr->nbr_nbma->t_poll);
 164
 165   return 0;
 166 }
 167
 168 int
 169 nsm_start (struct ospf_neighbor *nbr)
 170 {
 171
 172   nsm_reset_nbr (nbr);
 173
 174   if (nbr->nbr_nbma)
 175       OSPF_POLL_TIMER_OFF (nbr->nbr_nbma->t_poll);
 176
 177   OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
 178
 179   OSPF_NSM_TIMER_ON (nbr->t_inactivity, ospf_inactivity_timer,
 180                      nbr->v_inactivity);
 181
 182   return 0;
 183 }
 184
 185 int
 186 nsm_twoway_received (struct ospf_neighbor *nbr)
 187 {
 188   struct ospf_interface *oi;
 189   int next_state = NSM_TwoWay;
 190
 191   oi = nbr->oi;
 192
 193   /* These netowork types must be adjacency. */
 194   if (oi->type == OSPF_IFTYPE_POINTOPOINT ||
 195       oi->type == OSPF_IFTYPE_POINTOMULTIPOINT ||
 196       oi->type == OSPF_IFTYPE_VIRTUALLINK)
 197     next_state = NSM_ExStart;
 198
 199   /* Router itself is the DRouter or the BDRouter. */
 200   if (IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi)) ||
 201       IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi)))
 202     next_state = NSM_ExStart;
 203
 204   /* Neighboring Router is the DRouter or the BDRouter. */
 205   if (IPV4_ADDR_SAME (&nbr->address.u.prefix4, &nbr->d_router) ||
 206       IPV4_ADDR_SAME (&nbr->address.u.prefix4, &nbr->bd_router))
 207     next_state = NSM_ExStart;
 208
 209   return next_state;
 210 }
 211
 212 int
 213 ospf_db_summary_count (struct ospf_neighbor *nbr)
 214 {
 215   return ospf_lsdb_count_all (&nbr->db_sum);
 216 }
 217
 218 int
 219 ospf_db_summary_isempty (struct ospf_neighbor *nbr)
 220 {
 221   return ospf_lsdb_isempty (&nbr->db_sum);
 222 }
 223
 224 int
 225 ospf_db_summary_add (struct ospf_neighbor *nbr, struct ospf_lsa *lsa)
 226 {
 227 #ifdef HAVE_OPAQUE_LSA
 228   switch (lsa->data->type)
 229     {
 230     case OSPF_OPAQUE_LINK_LSA:
 231       /* Exclude type-9 LSAs that does not have the same "oi" with "nbr". */
 232       if (lsa->oi != nbr->oi)
 233           return 0;
 234       break;
 235     case OSPF_OPAQUE_AREA_LSA:
 236       /*
 237        * It is assured by the caller function "nsm_negotiation_done()"
 238        * that every given LSA belongs to the same area with "nbr".
 239        */
 240       break;
 241     case OSPF_OPAQUE_AS_LSA:
 242     default:
 243       break;
 244     }
 245 #endif /* HAVE_OPAQUE_LSA */
 246
 247 #ifdef HAVE_NSSA
 248   /* Stay away from any Local Translated Type-7 LSAs */
 249   if (CHECK_FLAG (lsa->flags, OSPF_LSA_LOCAL_XLT))
 250     return 0;
 251 #endif /* HAVE_NSSA */
 252
 253   if (IS_LSA_MAXAGE (lsa))
 254     ospf_ls_retransmit_add (nbr, lsa);
 255   else
 256     ospf_lsdb_add (&nbr->db_sum, lsa);
 257
 258   return 0;
 259 }
 260
 261 void
 262 ospf_db_summary_clear (struct ospf_neighbor *nbr)
 263 {
 264   struct ospf_lsdb *lsdb;
 265   int i;
 266
 267   lsdb = &nbr->db_sum;
 268   for (i = OSPF_MIN_LSA; i < OSPF_MAX_LSA; i++)
 269     {
 270       struct route_table *table = lsdb->type[i].db;
 271       struct route_node *rn;
 272
 273       for (rn = route_top (table); rn; rn = route_next (rn))
 274         if (rn->info)
 275           ospf_lsdb_delete (&nbr->db_sum, rn->info);
 276     }
 277 }
 278
 279 \f
 280
 281 /* The area link state database consists of the router-LSAs,
 282    network-LSAs and summary-LSAs contained in the area structure,
 283    along with the AS-external-LSAs contained in the global structure.
 284    AS-external-LSAs are omitted from a virtual neighbor's Database
 285    summary list.  AS-external-LSAs are omitted from the Database
 286    summary list if the area has been configured as a stub. */
 287 int
 288 nsm_negotiation_done (struct ospf_neighbor *nbr)
 289 {
 290   struct ospf_area *area = nbr->oi->area;
 291   struct ospf_lsa *lsa;
 292   struct route_node *rn;
 293
 294   LSDB_LOOP (ROUTER_LSDB (area), rn, lsa)
 295     ospf_db_summary_add (nbr, lsa);
 296   LSDB_LOOP (NETWORK_LSDB (area), rn, lsa)
 297     ospf_db_summary_add (nbr, lsa);
 298   LSDB_LOOP (SUMMARY_LSDB (area), rn, lsa)
 299     ospf_db_summary_add (nbr, lsa);
 300   LSDB_LOOP (ASBR_SUMMARY_LSDB (area), rn, lsa)
 301     ospf_db_summary_add (nbr, lsa);
 302
 303 #ifdef HAVE_OPAQUE_LSA
 304   /* Process only if the neighbor is opaque capable. */
 305   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 306     {
 307       LSDB_LOOP (OPAQUE_LINK_LSDB (area), rn, lsa)
 308         ospf_db_summary_add (nbr, lsa);
 309       LSDB_LOOP (OPAQUE_AREA_LSDB (area), rn, lsa)
 310         ospf_db_summary_add (nbr, lsa);
 311     }
 312 #endif /* HAVE_OPAQUE_LSA */
 313
 314   if (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
 315       && area->external_routing == OSPF_AREA_DEFAULT)
 316     LSDB_LOOP (EXTERNAL_LSDB (nbr->oi->ospf), rn, lsa)
 317       ospf_db_summary_add (nbr, lsa);
 318
 319 #ifdef HAVE_OPAQUE_LSA
 320   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O)
 321       && (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
 322           && area->external_routing == OSPF_AREA_DEFAULT))
 323     LSDB_LOOP (OPAQUE_AS_LSDB (nbr->oi->ospf), rn, lsa)
 324       ospf_db_summary_add (nbr, lsa);
 325 #endif /* HAVE_OPAQUE_LSA */
 326
 327   return 0;
 328 }
 329
 330 int
 331 nsm_exchange_done (struct ospf_neighbor *nbr)
 332 {
 333   if (ospf_ls_request_isempty (nbr))
 334     return NSM_Full;
 335
 336   /* Cancel dd retransmit timer. */
 337   /* OSPF_NSM_TIMER_OFF (nbr->t_db_desc); */
 338
 339   /* Send Link State Request. */
 340   ospf_ls_req_send (nbr);
 341
 342   return NSM_Loading;
 343 }
 344
 345 int
 346 nsm_bad_ls_req (struct ospf_neighbor *nbr)
 347 {
 348   /* Clear neighbor. */
 349   nsm_reset_nbr (nbr);
 350
 351   return 0;
 352 }
 353
 354 int
 355 nsm_adj_ok (struct ospf_neighbor *nbr)
 356 {
 357   struct ospf_interface *oi;
 358   int next_state;
 359   int flag = 0;
 360
 361   oi = nbr->oi;
 362   next_state = nbr->state;
 363
 364   /* These netowork types must be adjacency. */
 365   if (oi->type == OSPF_IFTYPE_POINTOPOINT
 366       || oi->type == OSPF_IFTYPE_POINTOMULTIPOINT
 367       || oi->type == OSPF_IFTYPE_VIRTUALLINK)
 368     flag = 1;
 369
 370   /* Router itself is the DRouter or the BDRouter. */
 371   if (IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi))
 372       || IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi)))
 373     flag = 1;
 374
 375   if (IPV4_ADDR_SAME (&nbr->address.u.prefix4, &DR (oi))
 376       || IPV4_ADDR_SAME (&nbr->address.u.prefix4, &BDR (oi)))
 377     flag = 1;
 378
 379   if (nbr->state == NSM_TwoWay && flag == 1)
 380     next_state = NSM_ExStart;
 381   else if (nbr->state >= NSM_ExStart && flag == 0)
 382     next_state = NSM_TwoWay;
 383
 384   return next_state;
 385 }
 386
 387 int
 388 nsm_seq_number_mismatch (struct ospf_neighbor *nbr)
 389 {
 390   /* Clear neighbor. */
 391   nsm_reset_nbr (nbr);
 392
 393   return 0;
 394 }
 395
 396 int
 397 nsm_oneway_received (struct ospf_neighbor *nbr)
 398 {
 399   /* Clear neighbor. */
 400   nsm_reset_nbr (nbr);
 401
 402   return 0;
 403 }
 404
 405 void
 406 nsm_reset_nbr (struct ospf_neighbor *nbr)
 407 {
 408   /* Clear Database Summary list. */
 409   if (!ospf_db_summary_isempty (nbr))
 410     ospf_db_summary_clear (nbr);
 411
 412   /* Clear Link State Request list. */
 413   if (!ospf_ls_request_isempty (nbr))
 414     ospf_ls_request_delete_all (nbr);
 415
 416   /* Clear Link State Retransmission list. */
 417   if (!ospf_ls_retransmit_isempty (nbr))
 418     ospf_ls_retransmit_clear (nbr);
 419
 420   /* Cancel thread. */
 421   OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 422   OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
 423   OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 424   OSPF_NSM_TIMER_OFF (nbr->t_hello_reply);
 425
 426 #ifdef HAVE_OPAQUE_LSA
 427   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 428     UNSET_FLAG (nbr->options, OSPF_OPTION_O);
 429 #endif /* HAVE_OPAQUE_LSA */
 430 }
 431
 432 int
 433 nsm_kill_nbr (struct ospf_neighbor *nbr)
 434 {
 435   /* call it here because we cannot call it from ospf_nsm_event */
 436   nsm_change_state (nbr, NSM_Down);
 437
 438   /* Reset neighbor. */
 439   nsm_reset_nbr (nbr);
 440
 441   if (nbr->oi->type == OSPF_IFTYPE_NBMA && nbr->nbr_nbma != NULL)
 442     {
 443       struct ospf_nbr_nbma *nbr_nbma = nbr->nbr_nbma;
 444
 445       nbr_nbma->nbr = NULL;
 446       nbr_nbma->state_change = nbr->state_change;
 447
 448       nbr->nbr_nbma = NULL;
 449
 450       OSPF_POLL_TIMER_ON (nbr_nbma->t_poll, ospf_poll_timer,
 451                           nbr_nbma->v_poll);
 452
 453       if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 454         zlog_info ("NSM[%s:%s]: Down (PollIntervalTimer scheduled)",
 455                    IF_NAME (nbr->oi), inet_ntoa (nbr->address.u.prefix4));
 456     }
 457
 458   /* Delete neighbor from interface. */
 459   ospf_nbr_delete (nbr);
 460
 461   return 0;
 462 }
 463
 464 int
 465 nsm_inactivity_timer (struct ospf_neighbor *nbr)
 466 {
 467   /* Kill neighbor. */
 468   nsm_kill_nbr (nbr);
 469
 470   return 0;
 471 }
 472
 473 int
 474 nsm_ll_down (struct ospf_neighbor *nbr)
 475 {
 476   /* Reset neighbor. */
 477   /*nsm_reset_nbr (nbr);*/
 478
 479   /* Kill neighbor. */
 480   nsm_kill_nbr (nbr);
 481
 482   return 0;
 483 }
 484
 485 /* Neighbor State Machine */
 486 struct {
 487   int (*func) ();
 488   int next_state;
 489 } NSM [OSPF_NSM_STATE_MAX][OSPF_NSM_EVENT_MAX] =
 490 {
 491   {
 492     /* DependUpon: dummy state. */
 493     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 494     { nsm_ignore,              NSM_DependUpon }, /* HelloReceived     */
 495     { nsm_ignore,              NSM_DependUpon }, /* Start             */
 496     { nsm_ignore,              NSM_DependUpon }, /* 2-WayReceived     */
 497     { nsm_ignore,              NSM_DependUpon }, /* NegotiationDone   */
 498     { nsm_ignore,              NSM_DependUpon }, /* ExchangeDone      */
 499     { nsm_ignore,              NSM_DependUpon }, /* BadLSReq          */
 500     { nsm_ignore,              NSM_DependUpon }, /* LoadingDone       */
 501     { nsm_ignore,              NSM_DependUpon }, /* AdjOK?            */
 502     { nsm_ignore,              NSM_DependUpon }, /* SeqNumberMismatch */
 503     { nsm_ignore,              NSM_DependUpon }, /* 1-WayReceived     */
 504     { nsm_ignore,              NSM_DependUpon }, /* KillNbr           */
 505     { nsm_ignore,              NSM_DependUpon }, /* InactivityTimer   */
 506     { nsm_ignore,              NSM_DependUpon }, /* LLDown            */
 507   },
 508   {
 509     /* Down: */
 510     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 511     { nsm_hello_received,      NSM_Init       }, /* HelloReceived     */
 512     { nsm_start,               NSM_Attempt    }, /* Start             */
 513     { nsm_ignore,              NSM_Down       }, /* 2-WayReceived     */
 514     { nsm_ignore,              NSM_Down       }, /* NegotiationDone   */
 515     { nsm_ignore,              NSM_Down       }, /* ExchangeDone      */
 516     { nsm_ignore,              NSM_Down       }, /* BadLSReq          */
 517     { nsm_ignore,              NSM_Down       }, /* LoadingDone       */
 518     { nsm_ignore,              NSM_Down       }, /* AdjOK?            */
 519     { nsm_ignore,              NSM_Down       }, /* SeqNumberMismatch */
 520     { nsm_ignore,              NSM_Down       }, /* 1-WayReceived     */
 521     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 522     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 523     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 524   },
 525   {
 526     /* Attempt: */
 527     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 528     { nsm_hello_received,      NSM_Init       }, /* HelloReceived     */
 529     { nsm_ignore,              NSM_Attempt    }, /* Start             */
 530     { nsm_ignore,              NSM_Attempt    }, /* 2-WayReceived     */
 531     { nsm_ignore,              NSM_Attempt    }, /* NegotiationDone   */
 532     { nsm_ignore,              NSM_Attempt    }, /* ExchangeDone      */
 533     { nsm_ignore,              NSM_Attempt    }, /* BadLSReq          */
 534     { nsm_ignore,              NSM_Attempt    }, /* LoadingDone       */
 535     { nsm_ignore,              NSM_Attempt    }, /* AdjOK?            */
 536     { nsm_ignore,              NSM_Attempt    }, /* SeqNumberMismatch */
 537     { nsm_ignore,              NSM_Attempt    }, /* 1-WayReceived     */
 538     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 539     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 540     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 541   },
 542   {
 543     /* Init: */
 544     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 545     { nsm_hello_received,      NSM_Init       }, /* HelloReceived     */
 546     { nsm_ignore,              NSM_Init       }, /* Start             */
 547     { nsm_twoway_received,     NSM_DependUpon }, /* 2-WayReceived     */
 548     { nsm_ignore,              NSM_Init       }, /* NegotiationDone   */
 549     { nsm_ignore,              NSM_Init       }, /* ExchangeDone      */
 550     { nsm_ignore,              NSM_Init       }, /* BadLSReq          */
 551     { nsm_ignore,              NSM_Init       }, /* LoadingDone       */
 552     { nsm_ignore,              NSM_Init       }, /* AdjOK?            */
 553     { nsm_ignore,              NSM_Init       }, /* SeqNumberMismatch */
 554     { nsm_ignore,              NSM_Init       }, /* 1-WayReceived     */
 555     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 556     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 557     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 558   },
 559   {
 560     /* 2-Way: */
 561     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 562     { nsm_hello_received,      NSM_TwoWay     }, /* HelloReceived     */
 563     { nsm_ignore,              NSM_TwoWay     }, /* Start             */
 564     { nsm_ignore,              NSM_TwoWay     }, /* 2-WayReceived     */
 565     { nsm_ignore,              NSM_TwoWay     }, /* NegotiationDone   */
 566     { nsm_ignore,              NSM_TwoWay     }, /* ExchangeDone      */
 567     { nsm_ignore,              NSM_TwoWay     }, /* BadLSReq          */
 568     { nsm_ignore,              NSM_TwoWay     }, /* LoadingDone       */
 569     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 570     { nsm_ignore,              NSM_TwoWay     }, /* SeqNumberMismatch */
 571     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 572     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 573     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 574     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 575   },
 576   {
 577     /* ExStart: */
 578     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 579     { nsm_hello_received,      NSM_ExStart    }, /* HelloReceived     */
 580     { nsm_ignore,              NSM_ExStart    }, /* Start             */
 581     { nsm_ignore,              NSM_ExStart    }, /* 2-WayReceived     */
 582     { nsm_negotiation_done,    NSM_Exchange   }, /* NegotiationDone   */
 583     { nsm_ignore,              NSM_ExStart    }, /* ExchangeDone      */
 584     { nsm_ignore,              NSM_ExStart    }, /* BadLSReq          */
 585     { nsm_ignore,              NSM_ExStart    }, /* LoadingDone       */
 586     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 587     { nsm_ignore,              NSM_ExStart    }, /* SeqNumberMismatch */
 588     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 589     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 590     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 591     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 592   },
 593   {
 594     /* Exchange: */
 595     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 596     { nsm_hello_received,      NSM_Exchange   }, /* HelloReceived     */
 597     { nsm_ignore,              NSM_Exchange   }, /* Start             */
 598     { nsm_ignore,              NSM_Exchange   }, /* 2-WayReceived     */
 599     { nsm_ignore,              NSM_Exchange   }, /* NegotiationDone   */
 600     { nsm_exchange_done,       NSM_DependUpon }, /* ExchangeDone      */
 601     { nsm_bad_ls_req,          NSM_ExStart    }, /* BadLSReq          */
 602     { nsm_ignore,              NSM_Exchange   }, /* LoadingDone       */
 603     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 604     { nsm_seq_number_mismatch, NSM_ExStart    }, /* SeqNumberMismatch */
 605     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 606     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 607     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 608     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 609   },
 610   {
 611     /* Loading: */
 612     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 613     { nsm_hello_received,      NSM_Loading    }, /* HelloReceived     */
 614     { nsm_ignore,              NSM_Loading    }, /* Start             */
 615     { nsm_ignore,              NSM_Loading    }, /* 2-WayReceived     */
 616     { nsm_ignore,              NSM_Loading    }, /* NegotiationDone   */
 617     { nsm_ignore,              NSM_Loading    }, /* ExchangeDone      */
 618     { nsm_bad_ls_req,          NSM_ExStart    }, /* BadLSReq          */
 619     { nsm_ignore,              NSM_Full       }, /* LoadingDone       */
 620     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 621     { nsm_seq_number_mismatch, NSM_ExStart    }, /* SeqNumberMismatch */
 622     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 623     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 624     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 625     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 626   },
 627   { /* Full: */
 628     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 629     { nsm_hello_received,      NSM_Full       }, /* HelloReceived     */
 630     { nsm_ignore,              NSM_Full       }, /* Start             */
 631     { nsm_ignore,              NSM_Full       }, /* 2-WayReceived     */
 632     { nsm_ignore,              NSM_Full       }, /* NegotiationDone   */
 633     { nsm_ignore,              NSM_Full       }, /* ExchangeDone      */
 634     { nsm_bad_ls_req,          NSM_ExStart    }, /* BadLSReq          */
 635     { nsm_ignore,              NSM_Full       }, /* LoadingDone       */
 636     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 637     { nsm_seq_number_mismatch, NSM_ExStart    }, /* SeqNumberMismatch */
 638     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 639     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 640     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 641     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 642   },
 643 };
 644
 645 static char *ospf_nsm_event_str[] =
 646 {
 647   "NoEvent",
 648   "HelloReceived",
 649   "Start",
 650   "2-WayReceived",
 651   "NegotiationDone",
 652   "ExchangeDone",
 653   "BadLSReq",
 654   "LoadingDone",
 655   "AdjOK?",
 656   "SeqNumberMismatch",
 657   "1-WayReceived",
 658   "KillNbr",
 659   "InactivityTimer",
 660   "LLDown",
 661 };
 662
 663 void
 664 nsm_change_state (struct ospf_neighbor *nbr, int state)
 665 {
 666   struct ospf_interface *oi = nbr->oi;
 667   struct ospf_area *vl_area = NULL;
 668   u_char old_state;
 669   int x;
 670   int force = 1;
 671
 672   /* Logging change of status. */
 673   if (IS_DEBUG_OSPF (nsm, NSM_STATUS))
 674     zlog_info ("NSM[%s:%s]: State change %s -> %s",
 675                IF_NAME (nbr->oi), inet_ntoa (nbr->router_id),
 676                LOOKUP (ospf_nsm_state_msg, nbr->state),
 677                LOOKUP (ospf_nsm_state_msg, state));
 678
 679   /* Preserve old status. */
 680   old_state = nbr->state;
 681
 682   /* Change to new status. */
 683   nbr->state = state;
 684
 685   /* Statistics. */
 686   nbr->state_change++;
 687
 688   if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
 689     vl_area = ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);
 690
 691   /* One of the neighboring routers changes to/from the FULL state. */
 692   if ((old_state != NSM_Full && state == NSM_Full) ||
 693       (old_state == NSM_Full && state != NSM_Full))
 694     {
 695       if (state == NSM_Full)
 696         {
 697           oi->full_nbrs++;
 698           oi->area->full_nbrs++;
 699
 700           ospf_check_abr_status (oi->ospf);
 701
 702           if (oi->type == OSPF_IFTYPE_VIRTUALLINK && vl_area)
 703             if (++vl_area->full_vls == 1)
 704               ospf_schedule_abr_task (oi->ospf);
 705
 706           /* kevinm: refresh any redistributions */
 707           for (x = ZEBRA_ROUTE_SYSTEM; x < ZEBRA_ROUTE_MAX; x++)
 708             {
 709               if (x == ZEBRA_ROUTE_OSPF || x == ZEBRA_ROUTE_OSPF6)
 710                 continue;
 711               ospf_external_lsa_refresh_type (oi->ospf, x, force);
 712             }
 713         }
 714       else
 715         {
 716           oi->full_nbrs--;
 717           oi->area->full_nbrs--;
 718
 719           ospf_check_abr_status (oi->ospf);
 720
 721           if (oi->type == OSPF_IFTYPE_VIRTUALLINK && vl_area)
 722             if (vl_area->full_vls > 0)
 723               if (--vl_area->full_vls == 0)
 724                 ospf_schedule_abr_task (oi->ospf);
 725
 726           /* clear neighbor retransmit list */
 727           if (!ospf_ls_retransmit_isempty (nbr))
 728             ospf_ls_retransmit_clear (nbr);
 729         }
 730
 731       zlog_info ("nsm_change_state(): "
 732                  "scheduling new router-LSA origination");
 733
 734       ospf_router_lsa_timer_add (oi->area);
 735
 736       if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
 737         {
 738           struct ospf_area *vl_area =
 739             ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);
 740
 741           if (vl_area)
 742             ospf_router_lsa_timer_add (vl_area);
 743         }
 744
 745       /* Originate network-LSA. */
 746       if (oi->state == ISM_DR)
 747         {
 748           if (oi->network_lsa_self && oi->full_nbrs == 0)
 749             {
 750               ospf_lsa_flush_area (oi->network_lsa_self, oi->area);
 751               ospf_lsa_unlock (oi->network_lsa_self);
 752               oi->network_lsa_self = NULL;
 753               OSPF_TIMER_OFF (oi->t_network_lsa_self);
 754             }
 755           else
 756             ospf_network_lsa_timer_add (oi);
 757         }
 758     }
 759
 760 #ifdef HAVE_OPAQUE_LSA
 761   ospf_opaque_nsm_change (nbr, old_state);
 762 #endif /* HAVE_OPAQUE_LSA */
 763
 764   /* Start DD exchange protocol */
 765   if (state == NSM_ExStart)
 766     {
 767       if (nbr->dd_seqnum == 0)
 768         nbr->dd_seqnum = time (NULL);
 769       else
 770         nbr->dd_seqnum++;
 771
 772       nbr->dd_flags = OSPF_DD_FLAG_I|OSPF_DD_FLAG_M|OSPF_DD_FLAG_MS;
 773       ospf_db_desc_send (nbr);
 774     }
 775
 776   /* clear cryptographic sequence number */
 777   if (state == NSM_Down)
 778     nbr->crypt_seqnum = 0;
 779
 780   /* Generete NeighborChange ISM event. */
 781 #ifdef BUGGY_ISM_TRANSITION
 782   if ((old_state < NSM_TwoWay && state >= NSM_TwoWay) ||
 783       (old_state >= NSM_TwoWay && state < NSM_TwoWay))
 784     OSPF_ISM_EVENT_EXECUTE (oi, ISM_NeighborChange);
 785 #else /* BUGGY_ISM_TRANSITION */
 786   switch (oi->state) {
 787   case ISM_DROther:
 788   case ISM_Backup:
 789   case ISM_DR:
 790     if ((old_state < NSM_TwoWay && state >= NSM_TwoWay) ||
 791         (old_state >= NSM_TwoWay && state < NSM_TwoWay))
 792       OSPF_ISM_EVENT_EXECUTE (oi, ISM_NeighborChange);
 793     break;
 794   default:
 795     /* ISM_PointToPoint -> ISM_Down, ISM_Loopback -> ISM_Down, etc. */
 796     break;
 797   }
 798 #endif /* BUGGY_ISM_TRANSITION */
 799
 800   /* Performance hack. Send hello immideately when some neighbor enter
 801      Init state.  This whay we decrease neighbor discovery time. Gleb.*/
 802   if (state == NSM_Init)
 803     {
 804       OSPF_ISM_TIMER_OFF (oi->t_hello);
 805       OSPF_ISM_TIMER_ON (oi->t_hello, ospf_hello_timer, 1);
 806     }
 807
 808   /* Preserve old status? */
 809 }
 810
 811 /* Execute NSM event process. */
 812 int
 813 ospf_nsm_event (struct thread *thread)
 814 {
 815   int event;
 816   int next_state;
 817   struct ospf_neighbor *nbr;
 818   struct in_addr router_id;
 819   int old_state;
 820   struct ospf_interface *oi;
 821
 822   nbr = THREAD_ARG (thread);
 823   event = THREAD_VAL (thread);
 824   router_id = nbr->router_id;
 825
 826   old_state = nbr->state;
 827   oi = nbr->oi ;
 828
 829   /* Call function. */
 830   next_state = (*(NSM [nbr->state][event].func))(nbr);
 831
 832   /* When event is NSM_KillNbr or InactivityTimer, the neighbor is
 833      deleted. */
 834   if (event == NSM_KillNbr || event == NSM_InactivityTimer)
 835     {
 836       if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 837         zlog_info ("NSM[%s:%s]: neighbor deleted",
 838                    IF_NAME (oi), inet_ntoa (router_id));
 839
 840       /* Timers are canceled in ospf_nbr_free, moreover we cannot call
 841          nsm_timer_set here because nbr is freed already!!!*/
 842       /*nsm_timer_set (nbr);*/
 843
 844       return 0;
 845     }
 846
 847   if (! next_state)
 848     next_state = NSM [nbr->state][event].next_state;
 849
 850   if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 851     zlog_info ("NSM[%s:%s]: %s (%s)", IF_NAME (oi),
 852                inet_ntoa (nbr->router_id),
 853                LOOKUP (ospf_nsm_state_msg, nbr->state),
 854                ospf_nsm_event_str [event]);
 855
 856   /* If state is changed. */
 857   if (next_state != nbr->state)
 858     nsm_change_state (nbr, next_state);
 859
 860   /* Make sure timer is set. */
 861   nsm_timer_set (nbr);
 862
 863   return 0;
 864 }
 865
 866 /* Check loading state. */
 867 void
 868 ospf_check_nbr_loading (struct ospf_neighbor *nbr)
 869 {
 870   if (nbr->state == NSM_Loading)
 871     {
 872       if (ospf_ls_request_isempty (nbr))
 873         OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_LoadingDone);
 874       else if (nbr->ls_req_last == NULL)
 875         ospf_ls_req_event (nbr);
 876     }
 877 }