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 #include "ospfd/ospf_snmp.h"
  51 #include "ospfd/ospf_bfd.h"
  52
  53 static void nsm_clear_adj (struct ospf_neighbor *);
  54
  55 /* OSPF NSM Timer functions. */
  56 static int
  57 ospf_inactivity_timer (struct thread *thread)
  58 {
  59   struct ospf_neighbor *nbr;
  60
  61   nbr = THREAD_ARG (thread);
  62   nbr->t_inactivity = NULL;
  63
  64   if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))
  65     zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: Timer (Inactivity timer expire)",
  66           IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));
  67
  68   OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_InactivityTimer);
  69
  70   return 0;
  71 }
  72
  73 static int
  74 ospf_db_desc_timer (struct thread *thread)
  75 {
  76   struct ospf_neighbor *nbr;
  77
  78   nbr = THREAD_ARG (thread);
  79   nbr->t_db_desc = NULL;
  80
  81   if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))
  82     zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: Timer (DD Retransmit timer expire)",
  83           IF_NAME (nbr->oi), inet_ntoa (nbr->src));
  84
  85   /* resent last send DD packet. */
  86   assert (nbr->last_send);
  87   ospf_db_desc_resend (nbr);
  88
  89   /* DD Retransmit timer set. */
  90   OSPF_NSM_TIMER_ON (nbr->t_db_desc, ospf_db_desc_timer, nbr->v_db_desc);
  91
  92   return 0;
  93 }
  94
  95 /* Hook function called after ospf NSM event is occured.
  96  *
  97  * Set/clear any timers whose condition is implicit to the neighbour
  98  * state. There may be other timers which are set/unset according to other
  99  * state.
 100  *
 101  * We rely on this function to properly clear timers in lower states,
 102  * particularly before deleting a neighbour.
 103  */
 104 static void
 105 nsm_timer_set (struct ospf_neighbor *nbr)
 106 {
 107   switch (nbr->state)
 108     {
 109     case NSM_Deleted:
 110     case NSM_Down:
 111       OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
 112       OSPF_NSM_TIMER_OFF (nbr->t_hello_reply);
 113     case NSM_Attempt:
 114     case NSM_Init:
 115     case NSM_TwoWay:
 116       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 117       OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 118       OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
 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       OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
 124       break;
 125     case NSM_Exchange:
 126       OSPF_NSM_TIMER_ON (nbr->t_ls_upd, ospf_ls_upd_timer, nbr->v_ls_upd);
 127       if (!IS_SET_DD_MS (nbr->dd_flags))
 128         OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 129       break;
 130     case NSM_Loading:
 131     case NSM_Full:
 132     default:
 133       OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 134       break;
 135     }
 136 }
 137
 138 /* 10.4 of RFC2328, indicate whether an adjacency is appropriate with
 139  * the given neighbour
 140  */
 141 static int
 142 nsm_should_adj (struct ospf_neighbor *nbr)
 143 {
 144   struct ospf_interface *oi = nbr->oi;
 145
 146       /* These network types must always form adjacencies. */
 147   if (oi->type == OSPF_IFTYPE_POINTOPOINT
 148       || oi->type == OSPF_IFTYPE_POINTOMULTIPOINT
 149       || oi->type == OSPF_IFTYPE_VIRTUALLINK
 150       /* Router itself is the DRouter or the BDRouter. */
 151       || IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi))
 152       || IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi))
 153       /* Neighboring Router is the DRouter or the BDRouter. */
 154       || IPV4_ADDR_SAME (&nbr->address.u.prefix4, &DR (oi))
 155       || IPV4_ADDR_SAME (&nbr->address.u.prefix4, &BDR (oi)))
 156     return 1;
 157
 158   return 0;
 159 }
 160
 161 /* OSPF NSM functions. */
 162 static int
 163 nsm_packet_received (struct ospf_neighbor *nbr)
 164 {
 165   /* Start or Restart Inactivity Timer. */
 166   OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
 167
 168   OSPF_NSM_TIMER_ON (nbr->t_inactivity, ospf_inactivity_timer,
 169                      nbr->v_inactivity);
 170
 171   if (nbr->oi->type == OSPF_IFTYPE_NBMA && nbr->nbr_nbma)
 172     OSPF_POLL_TIMER_OFF (nbr->nbr_nbma->t_poll);
 173
 174   /* Send proactive ARP requests */
 175   if (nbr->state < NSM_Exchange)
 176       ospf_proactively_arp (nbr);
 177
 178   return 0;
 179 }
 180
 181 static int
 182 nsm_start (struct ospf_neighbor *nbr)
 183 {
 184   if (nbr->nbr_nbma)
 185       OSPF_POLL_TIMER_OFF (nbr->nbr_nbma->t_poll);
 186
 187   OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
 188
 189   OSPF_NSM_TIMER_ON (nbr->t_inactivity, ospf_inactivity_timer,
 190                      nbr->v_inactivity);
 191
 192   /* Send proactive ARP requests */
 193   ospf_proactively_arp (nbr);
 194
 195   return 0;
 196 }
 197
 198 static int
 199 nsm_twoway_received (struct ospf_neighbor *nbr)
 200 {
 201   int adj = nsm_should_adj (nbr);
 202
 203   /* Send proactive ARP requests */
 204   if (adj)
 205      ospf_proactively_arp (nbr);
 206
 207   return (adj ? NSM_ExStart : NSM_TwoWay);
 208 }
 209
 210 int
 211 ospf_db_summary_count (struct ospf_neighbor *nbr)
 212 {
 213   return ospf_lsdb_count_all (&nbr->db_sum);
 214 }
 215
 216 int
 217 ospf_db_summary_isempty (struct ospf_neighbor *nbr)
 218 {
 219   return ospf_lsdb_isempty (&nbr->db_sum);
 220 }
 221
 222 static int
 223 ospf_db_summary_add (struct ospf_neighbor *nbr, struct ospf_lsa *lsa)
 224 {
 225 #ifdef HAVE_OPAQUE_LSA
 226   switch (lsa->data->type)
 227     {
 228     case OSPF_OPAQUE_LINK_LSA:
 229       /* Exclude type-9 LSAs that does not have the same "oi" with "nbr". */
 230       if (nbr->oi && ospf_if_exists (lsa->oi) != nbr->oi)
 231           return 0;
 232       break;
 233     case OSPF_OPAQUE_AREA_LSA:
 234       /*
 235        * It is assured by the caller function "nsm_negotiation_done()"
 236        * that every given LSA belongs to the same area with "nbr".
 237        */
 238       break;
 239     case OSPF_OPAQUE_AS_LSA:
 240     default:
 241       break;
 242     }
 243 #endif /* HAVE_OPAQUE_LSA */
 244
 245   /* Stay away from any Local Translated Type-7 LSAs */
 246   if (CHECK_FLAG (lsa->flags, OSPF_LSA_LOCAL_XLT))
 247     return 0;
 248
 249   if (IS_LSA_MAXAGE (lsa))
 250     ospf_ls_retransmit_add (nbr, lsa);
 251   else
 252     ospf_lsdb_add (&nbr->db_sum, lsa);
 253
 254   return 0;
 255 }
 256
 257 void
 258 ospf_db_summary_clear (struct ospf_neighbor *nbr)
 259 {
 260   struct ospf_lsdb *lsdb;
 261   int i;
 262
 263   lsdb = &nbr->db_sum;
 264   for (i = OSPF_MIN_LSA; i < OSPF_MAX_LSA; i++)
 265     {
 266       struct route_table *table = lsdb->type[i].db;
 267       struct route_node *rn;
 268
 269       for (rn = route_top (table); rn; rn = route_next (rn))
 270         if (rn->info)
 271           ospf_lsdb_delete (&nbr->db_sum, rn->info);
 272     }
 273 }
 274
 275
 276
 277 /* The area link state database consists of the router-LSAs,
 278    network-LSAs and summary-LSAs contained in the area structure,
 279    along with the AS-external-LSAs contained in the global structure.
 280    AS-external-LSAs are omitted from a virtual neighbor's Database
 281    summary list.  AS-external-LSAs are omitted from the Database
 282    summary list if the area has been configured as a stub. */
 283 static int
 284 nsm_negotiation_done (struct ospf_neighbor *nbr)
 285 {
 286   struct ospf_area *area = nbr->oi->area;
 287   struct ospf_lsa *lsa;
 288   struct route_node *rn;
 289
 290   /* Send proactive ARP requests */
 291   ospf_proactively_arp (nbr);
 292
 293   LSDB_LOOP (ROUTER_LSDB (area), rn, lsa)
 294     ospf_db_summary_add (nbr, lsa);
 295   LSDB_LOOP (NETWORK_LSDB (area), rn, lsa)
 296     ospf_db_summary_add (nbr, lsa);
 297   LSDB_LOOP (SUMMARY_LSDB (area), rn, lsa)
 298     ospf_db_summary_add (nbr, lsa);
 299   LSDB_LOOP (ASBR_SUMMARY_LSDB (area), rn, lsa)
 300     ospf_db_summary_add (nbr, lsa);
 301
 302 #ifdef HAVE_OPAQUE_LSA
 303   /* Process only if the neighbor is opaque capable. */
 304   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 305     {
 306       LSDB_LOOP (OPAQUE_LINK_LSDB (area), rn, lsa)
 307         ospf_db_summary_add (nbr, lsa);
 308       LSDB_LOOP (OPAQUE_AREA_LSDB (area), rn, lsa)
 309         ospf_db_summary_add (nbr, lsa);
 310     }
 311 #endif /* HAVE_OPAQUE_LSA */
 312
 313   if (CHECK_FLAG (nbr->options, OSPF_OPTION_NP))
 314     {
 315       LSDB_LOOP (NSSA_LSDB (area), rn, lsa)
 316         ospf_db_summary_add (nbr, lsa);
 317     }
 318
 319   if (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
 320       && area->external_routing == OSPF_AREA_DEFAULT)
 321     LSDB_LOOP (EXTERNAL_LSDB (nbr->oi->ospf), rn, lsa)
 322       ospf_db_summary_add (nbr, lsa);
 323
 324 #ifdef HAVE_OPAQUE_LSA
 325   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O)
 326       && (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
 327           && area->external_routing == OSPF_AREA_DEFAULT))
 328     LSDB_LOOP (OPAQUE_AS_LSDB (nbr->oi->ospf), rn, lsa)
 329       ospf_db_summary_add (nbr, lsa);
 330 #endif /* HAVE_OPAQUE_LSA */
 331
 332   return 0;
 333 }
 334
 335 static int
 336 nsm_exchange_done (struct ospf_neighbor *nbr)
 337 {
 338   if (ospf_ls_request_isempty (nbr))
 339     return NSM_Full;
 340
 341   /* Send Link State Request. */
 342   if (nbr->t_ls_req == NULL)
 343     ospf_ls_req_send (nbr);
 344
 345   return NSM_Loading;
 346 }
 347
 348 static int
 349 nsm_adj_ok (struct ospf_neighbor *nbr)
 350 {
 351   int next_state = nbr->state;
 352   int adj = nsm_should_adj (nbr);
 353
 354   if (nbr->state == NSM_TwoWay && adj == 1)
 355     {
 356       next_state = NSM_ExStart;
 357
 358       /* Send proactive ARP requests */
 359       ospf_proactively_arp (nbr);
 360     }
 361   else if (nbr->state >= NSM_ExStart && adj == 0)
 362     next_state = NSM_TwoWay;
 363
 364   return next_state;
 365 }
 366
 367 /* Clear adjacency related state for a neighbour, intended where nbr
 368  * transitions from > ExStart (i.e. a Full or forming adjacency)
 369  * to <= ExStart.
 370  */
 371 static void
 372 nsm_clear_adj (struct ospf_neighbor *nbr)
 373 {
 374   /* Clear Database Summary list. */
 375   if (!ospf_db_summary_isempty (nbr))
 376     ospf_db_summary_clear (nbr);
 377
 378   /* Clear Link State Request list. */
 379   if (!ospf_ls_request_isempty (nbr))
 380     ospf_ls_request_delete_all (nbr);
 381
 382   /* Clear Link State Retransmission list. */
 383   if (!ospf_ls_retransmit_isempty (nbr))
 384     ospf_ls_retransmit_clear (nbr);
 385
 386 #ifdef HAVE_OPAQUE_LSA
 387   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 388     UNSET_FLAG (nbr->options, OSPF_OPTION_O);
 389 #endif /* HAVE_OPAQUE_LSA */
 390 }
 391
 392 static int
 393 nsm_kill_nbr (struct ospf_neighbor *nbr)
 394 {
 395   /* killing nbr_self is invalid */
 396   if (nbr == nbr->oi->nbr_self)
 397     {
 398       assert (nbr != nbr->oi->nbr_self);
 399       return 0;
 400     }
 401
 402   if (nbr->oi->type == OSPF_IFTYPE_NBMA && nbr->nbr_nbma != NULL)
 403     {
 404       struct ospf_nbr_nbma *nbr_nbma = nbr->nbr_nbma;
 405
 406       nbr_nbma->nbr = NULL;
 407       nbr_nbma->state_change = nbr->state_change;
 408
 409       nbr->nbr_nbma = NULL;
 410
 411       OSPF_POLL_TIMER_ON (nbr_nbma->t_poll, ospf_poll_timer,
 412                           nbr_nbma->v_poll);
 413
 414       if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 415         zlog_debug ("NSM[%s:%s]: Down (PollIntervalTimer scheduled)",
 416                    IF_NAME (nbr->oi), inet_ntoa (nbr->address.u.prefix4));
 417     }
 418
 419   return 0;
 420 }
 421
 422 /* Neighbor State Machine */
 423 struct {
 424   int (*func) (struct ospf_neighbor *);
 425   int next_state;
 426 } NSM [OSPF_NSM_STATE_MAX][OSPF_NSM_EVENT_MAX] =
 427 {
 428   {
 429     /* DependUpon: dummy state. */
 430     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 431     { NULL,                    NSM_DependUpon }, /* PacketReceived    */
 432     { NULL,                    NSM_DependUpon }, /* Start             */
 433     { NULL,                    NSM_DependUpon }, /* 2-WayReceived     */
 434     { NULL,                    NSM_DependUpon }, /* NegotiationDone   */
 435     { NULL,                    NSM_DependUpon }, /* ExchangeDone      */
 436     { NULL,                    NSM_DependUpon }, /* BadLSReq          */
 437     { NULL,                    NSM_DependUpon }, /* LoadingDone       */
 438     { NULL,                    NSM_DependUpon }, /* AdjOK?            */
 439     { NULL,                    NSM_DependUpon }, /* SeqNumberMismatch */
 440     { NULL,                    NSM_DependUpon }, /* 1-WayReceived     */
 441     { NULL,                    NSM_DependUpon }, /* KillNbr           */
 442     { NULL,                    NSM_DependUpon }, /* InactivityTimer   */
 443     { NULL,                    NSM_DependUpon }, /* LLDown            */
 444   },
 445   {
 446     /* Deleted: dummy state. */
 447     { NULL,                    NSM_Deleted    }, /* NoEvent           */
 448     { NULL,                    NSM_Deleted    }, /* PacketReceived    */
 449     { NULL,                    NSM_Deleted    }, /* Start             */
 450     { NULL,                    NSM_Deleted    }, /* 2-WayReceived     */
 451     { NULL,                    NSM_Deleted    }, /* NegotiationDone   */
 452     { NULL,                    NSM_Deleted    }, /* ExchangeDone      */
 453     { NULL,                    NSM_Deleted    }, /* BadLSReq          */
 454     { NULL,                    NSM_Deleted    }, /* LoadingDone       */
 455     { NULL,                    NSM_Deleted    }, /* AdjOK?            */
 456     { NULL,                    NSM_Deleted    }, /* SeqNumberMismatch */
 457     { NULL,                    NSM_Deleted    }, /* 1-WayReceived     */
 458     { NULL,                    NSM_Deleted    }, /* KillNbr           */
 459     { NULL,                    NSM_Deleted    }, /* InactivityTimer   */
 460     { NULL,                    NSM_Deleted    }, /* LLDown            */
 461   },
 462   {
 463     /* Down: */
 464     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 465     { nsm_packet_received,     NSM_Init       }, /* PacketReceived    */
 466     { nsm_start,               NSM_Attempt    }, /* Start             */
 467     { NULL,                    NSM_Down       }, /* 2-WayReceived     */
 468     { NULL,                    NSM_Down       }, /* NegotiationDone   */
 469     { NULL,                    NSM_Down       }, /* ExchangeDone      */
 470     { NULL,                    NSM_Down       }, /* BadLSReq          */
 471     { NULL,                    NSM_Down       }, /* LoadingDone       */
 472     { NULL,                    NSM_Down       }, /* AdjOK?            */
 473     { NULL,                    NSM_Down       }, /* SeqNumberMismatch */
 474     { NULL,                    NSM_Down       }, /* 1-WayReceived     */
 475     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 476     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 477     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 478   },
 479   {
 480     /* Attempt: */
 481     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 482     { nsm_packet_received,     NSM_Init       }, /* PacketReceived    */
 483     { NULL,                    NSM_Attempt    }, /* Start             */
 484     { NULL,                    NSM_Attempt    }, /* 2-WayReceived     */
 485     { NULL,                    NSM_Attempt    }, /* NegotiationDone   */
 486     { NULL,                    NSM_Attempt    }, /* ExchangeDone      */
 487     { NULL,                    NSM_Attempt    }, /* BadLSReq          */
 488     { NULL,                    NSM_Attempt    }, /* LoadingDone       */
 489     { NULL,                    NSM_Attempt    }, /* AdjOK?            */
 490     { NULL,                    NSM_Attempt    }, /* SeqNumberMismatch */
 491     { NULL,                    NSM_Attempt    }, /* 1-WayReceived     */
 492     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 493     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 494     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 495   },
 496   {
 497     /* Init: */
 498     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 499     { nsm_packet_received,     NSM_Init      }, /* PacketReceived    */
 500     { NULL,                    NSM_Init       }, /* Start             */
 501     { nsm_twoway_received,     NSM_DependUpon }, /* 2-WayReceived     */
 502     { NULL,                    NSM_Init       }, /* NegotiationDone   */
 503     { NULL,                    NSM_Init       }, /* ExchangeDone      */
 504     { NULL,                    NSM_Init       }, /* BadLSReq          */
 505     { NULL,                    NSM_Init       }, /* LoadingDone       */
 506     { NULL,                    NSM_Init       }, /* AdjOK?            */
 507     { NULL,                    NSM_Init       }, /* SeqNumberMismatch */
 508     { NULL,                    NSM_Init       }, /* 1-WayReceived     */
 509     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 510     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 511     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 512   },
 513   {
 514     /* 2-Way: */
 515     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 516     { nsm_packet_received,     NSM_TwoWay     }, /* HelloReceived     */
 517     { NULL,                    NSM_TwoWay     }, /* Start             */
 518     { NULL,                    NSM_TwoWay     }, /* 2-WayReceived     */
 519     { NULL,                    NSM_TwoWay     }, /* NegotiationDone   */
 520     { NULL,                    NSM_TwoWay     }, /* ExchangeDone      */
 521     { NULL,                    NSM_TwoWay     }, /* BadLSReq          */
 522     { NULL,                    NSM_TwoWay     }, /* LoadingDone       */
 523     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 524     { NULL,                    NSM_TwoWay     }, /* SeqNumberMismatch */
 525     { NULL,                    NSM_Init       }, /* 1-WayReceived     */
 526     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 527     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 528     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 529   },
 530   {
 531     /* ExStart: */
 532     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 533     { nsm_packet_received,     NSM_ExStart    }, /* PacaketReceived   */
 534     { NULL,                    NSM_ExStart    }, /* Start             */
 535     { NULL,                    NSM_ExStart    }, /* 2-WayReceived     */
 536     { nsm_negotiation_done,    NSM_Exchange   }, /* NegotiationDone   */
 537     { NULL,                    NSM_ExStart    }, /* ExchangeDone      */
 538     { NULL,                    NSM_ExStart    }, /* BadLSReq          */
 539     { NULL,                    NSM_ExStart    }, /* LoadingDone       */
 540     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 541     { NULL,                    NSM_ExStart    }, /* SeqNumberMismatch */
 542     { NULL,                    NSM_Init       }, /* 1-WayReceived     */
 543     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 544     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 545     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 546   },
 547   {
 548     /* Exchange: */
 549     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 550     { nsm_packet_received,     NSM_Exchange   }, /* PacketReceived    */
 551     { NULL,                    NSM_Exchange   }, /* Start             */
 552     { NULL,                    NSM_Exchange   }, /* 2-WayReceived     */
 553     { NULL,                    NSM_Exchange   }, /* NegotiationDone   */
 554     { nsm_exchange_done,       NSM_DependUpon }, /* ExchangeDone      */
 555     { NULL,                    NSM_ExStart    }, /* BadLSReq          */
 556     { NULL,                    NSM_Exchange   }, /* LoadingDone       */
 557     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 558     { NULL,                    NSM_ExStart    }, /* SeqNumberMismatch */
 559     { NULL,                    NSM_Init       }, /* 1-WayReceived     */
 560     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 561     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 562     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 563   },
 564   {
 565     /* Loading: */
 566     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 567     { nsm_packet_received,     NSM_Loading    }, /* PacketReceived    */
 568     { NULL,                    NSM_Loading    }, /* Start             */
 569     { NULL,                    NSM_Loading    }, /* 2-WayReceived     */
 570     { NULL,                    NSM_Loading    }, /* NegotiationDone   */
 571     { NULL,                    NSM_Loading    }, /* ExchangeDone      */
 572     { NULL,                    NSM_ExStart    }, /* BadLSReq          */
 573     { NULL,                    NSM_Full       }, /* LoadingDone       */
 574     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 575     { NULL,                    NSM_ExStart    }, /* SeqNumberMismatch */
 576     { NULL,                    NSM_Init       }, /* 1-WayReceived     */
 577     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 578     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 579     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 580   },
 581   { /* Full: */
 582     { NULL,                    NSM_DependUpon }, /* NoEvent           */
 583     { nsm_packet_received,     NSM_Full       }, /* PacketReceived    */
 584     { NULL,                    NSM_Full       }, /* Start             */
 585     { NULL,                    NSM_Full       }, /* 2-WayReceived     */
 586     { NULL,                    NSM_Full       }, /* NegotiationDone   */
 587     { NULL,                    NSM_Full       }, /* ExchangeDone      */
 588     { NULL,                    NSM_ExStart    }, /* BadLSReq          */
 589     { NULL,                    NSM_Full       }, /* LoadingDone       */
 590     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 591     { NULL,                    NSM_ExStart    }, /* SeqNumberMismatch */
 592     { NULL,                    NSM_Init       }, /* 1-WayReceived     */
 593     { nsm_kill_nbr,            NSM_Deleted    }, /* KillNbr           */
 594     { nsm_kill_nbr,            NSM_Deleted    }, /* InactivityTimer   */
 595     { nsm_kill_nbr,            NSM_Deleted    }, /* LLDown            */
 596   },
 597 };
 598
 599 static const char *ospf_nsm_event_str[] =
 600 {
 601   "NoEvent",
 602   "PacketReceived",
 603   "Start",
 604   "2-WayReceived",
 605   "NegotiationDone",
 606   "ExchangeDone",
 607   "BadLSReq",
 608   "LoadingDone",
 609   "AdjOK?",
 610   "SeqNumberMismatch",
 611   "1-WayReceived",
 612   "KillNbr",
 613   "InactivityTimer",
 614   "LLDown",
 615 };
 616
 617 static void
 618 nsm_notice_state_change (struct ospf_neighbor *nbr, int next_state, int event)
 619 {
 620   /* Logging change of status. */
 621   if (IS_DEBUG_OSPF (nsm, NSM_STATUS))
 622     zlog_debug ("NSM[%s:%s]: State change %s -> %s (%s)",
 623                IF_NAME (nbr->oi), inet_ntoa (nbr->router_id),
 624                LOOKUP (ospf_nsm_state_msg, nbr->state),
 625                LOOKUP (ospf_nsm_state_msg, next_state),
 626                ospf_nsm_event_str [event]);
 627
 628   /* Optionally notify about adjacency changes */
 629   if (CHECK_FLAG(nbr->oi->ospf->config, OSPF_LOG_ADJACENCY_CHANGES) &&
 630       (CHECK_FLAG(nbr->oi->ospf->config, OSPF_LOG_ADJACENCY_DETAIL) ||
 631        (next_state == NSM_Full) || (next_state < nbr->state)))
 632     zlog_notice("AdjChg: Nbr %s on %s: %s -> %s (%s)",
 633                 inet_ntoa (nbr->router_id), IF_NAME (nbr->oi),
 634                 LOOKUP (ospf_nsm_state_msg, nbr->state),
 635                 LOOKUP (ospf_nsm_state_msg, next_state),
 636                 ospf_nsm_event_str [event]);
 637
 638   /* Advance in NSM */
 639   if (next_state > nbr->state)
 640     nbr->ts_last_progress = recent_relative_time ();
 641   else /* regression in NSM */
 642     {
 643       nbr->ts_last_regress = recent_relative_time ();
 644       nbr->last_regress_str = ospf_nsm_event_str [event];
 645     }
 646
 647 }
 648
 649 static void
 650 nsm_change_state (struct ospf_neighbor *nbr, int state)
 651 {
 652   struct ospf_interface *oi = nbr->oi;
 653   struct ospf_area *vl_area = NULL;
 654   u_char old_state;
 655   int x;
 656   int force = 1;
 657
 658   /* Preserve old status. */
 659   old_state = nbr->state;
 660
 661   /* Change to new status. */
 662   nbr->state = state;
 663
 664   /* Statistics. */
 665   nbr->state_change++;
 666
 667   if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
 668     vl_area = ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);
 669
 670   /* Generate NeighborChange ISM event.
 671    *
 672    * In response to NeighborChange, DR election is rerun. The information
 673    * from the election process is required by the router-lsa construction.
 674    *
 675    * Therefore, trigger the event prior to refreshing the LSAs. */
 676   switch (oi->state) {
 677   case ISM_DROther:
 678   case ISM_Backup:
 679   case ISM_DR:
 680     if ((old_state < NSM_TwoWay && state >= NSM_TwoWay) ||
 681         (old_state >= NSM_TwoWay && state < NSM_TwoWay))
 682       OSPF_ISM_EVENT_EXECUTE (oi, ISM_NeighborChange);
 683     break;
 684   default:
 685     /* ISM_PointToPoint -> ISM_Down, ISM_Loopback -> ISM_Down, etc. */
 686     break;
 687   }
 688
 689   /* One of the neighboring routers changes to/from the FULL state. */
 690   if ((old_state != NSM_Full && state == NSM_Full) ||
 691       (old_state == NSM_Full && state != NSM_Full))
 692     {
 693       if (state == NSM_Full)
 694         {
 695           oi->full_nbrs++;
 696           oi->area->full_nbrs++;
 697
 698           ospf_check_abr_status (oi->ospf);
 699
 700           if (oi->type == OSPF_IFTYPE_VIRTUALLINK && vl_area)
 701             if (++vl_area->full_vls == 1)
 702               ospf_schedule_abr_task (oi->ospf);
 703
 704           /* kevinm: refresh any redistributions */
 705           for (x = ZEBRA_ROUTE_SYSTEM; x < ZEBRA_ROUTE_MAX; x++)
 706             {
 707               struct list *red_list;
 708               struct listnode *node;
 709               struct ospf_redist *red;
 710
 711               if (x == ZEBRA_ROUTE_OSPF6)
 712                 continue;
 713
 714               red_list = oi->ospf->redist[x];
 715               if (!red_list)
 716                 continue;
 717
 718               for (ALL_LIST_ELEMENTS_RO(red_list, node, red))
 719                 ospf_external_lsa_refresh_type (oi->ospf, x, red->instance, force);
 720             }
 721           /* XXX: Clearly some thing is wrong with refresh of external LSAs
 722            * this added to hack around defaults not refreshing after a timer
 723            * jump.
 724            */
 725           ospf_external_lsa_refresh_default (oi->ospf);
 726         }
 727       else
 728         {
 729           oi->full_nbrs--;
 730           oi->area->full_nbrs--;
 731
 732           ospf_check_abr_status (oi->ospf);
 733
 734           if (oi->type == OSPF_IFTYPE_VIRTUALLINK && vl_area)
 735             if (vl_area->full_vls > 0)
 736               if (--vl_area->full_vls == 0)
 737                 ospf_schedule_abr_task (oi->ospf);
 738         }
 739
 740       zlog_info ("nsm_change_state(%s, %s -> %s): "
 741                  "scheduling new router-LSA origination",
 742                  inet_ntoa (nbr->router_id),
 743                  LOOKUP(ospf_nsm_state_msg, old_state),
 744                  LOOKUP(ospf_nsm_state_msg, state));
 745
 746       ospf_router_lsa_update_area (oi->area);
 747
 748       if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
 749         {
 750           struct ospf_area *vl_area =
 751             ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);
 752
 753           if (vl_area)
 754             ospf_router_lsa_update_area (vl_area);
 755         }
 756
 757       /* Originate network-LSA. */
 758       if (oi->state == ISM_DR)
 759         {
 760           if (oi->network_lsa_self && oi->full_nbrs == 0)
 761             {
 762               ospf_lsa_flush_area (oi->network_lsa_self, oi->area);
 763               ospf_lsa_unlock (&oi->network_lsa_self);
 764               oi->network_lsa_self = NULL;
 765             }
 766           else
 767             ospf_network_lsa_update (oi);
 768         }
 769     }
 770
 771 #ifdef HAVE_OPAQUE_LSA
 772   ospf_opaque_nsm_change (nbr, old_state);
 773 #endif /* HAVE_OPAQUE_LSA */
 774
 775   /* State changes from > ExStart to <= ExStart should clear any Exchange
 776    * or Full/LSA Update related lists and state.
 777    * Potential causal events: BadLSReq, SeqNumberMismatch, AdjOK?
 778    */
 779   if ((old_state > NSM_ExStart) && (state <= NSM_ExStart))
 780     nsm_clear_adj (nbr);
 781
 782   /* Start DD exchange protocol */
 783   if (state == NSM_ExStart)
 784     {
 785       if (nbr->dd_seqnum == 0)
 786         nbr->dd_seqnum = quagga_time (NULL);
 787       else
 788         nbr->dd_seqnum++;
 789
 790       nbr->dd_flags = OSPF_DD_FLAG_I|OSPF_DD_FLAG_M|OSPF_DD_FLAG_MS;
 791       ospf_db_desc_send (nbr);
 792     }
 793
 794   /* clear cryptographic sequence number */
 795   if (state == NSM_Down)
 796     nbr->crypt_seqnum = 0;
 797
 798   ospf_bfd_trigger_event(nbr, old_state, state);
 799
 800   /* Preserve old status? */
 801 }
 802
 803 /* Execute NSM event process. */
 804 int
 805 ospf_nsm_event (struct thread *thread)
 806 {
 807   int event;
 808   int next_state;
 809   struct ospf_neighbor *nbr;
 810
 811   nbr = THREAD_ARG (thread);
 812   event = THREAD_VAL (thread);
 813
 814   if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 815     zlog_debug ("NSM[%s:%s]: %s (%s)", IF_NAME (nbr->oi),
 816                inet_ntoa (nbr->router_id),
 817                LOOKUP (ospf_nsm_state_msg, nbr->state),
 818                ospf_nsm_event_str [event]);
 819
 820   next_state = NSM [nbr->state][event].next_state;
 821
 822   /* Call function. */
 823   if (NSM [nbr->state][event].func != NULL)
 824     {
 825       int func_state = (*(NSM [nbr->state][event].func))(nbr);
 826
 827       if (NSM [nbr->state][event].next_state == NSM_DependUpon)
 828         next_state = func_state;
 829       else if (func_state)
 830         {
 831           /* There's a mismatch between the FSM tables and what an FSM
 832            * action/state-change function returned. State changes which
 833            * do not have conditional/DependUpon next-states should not
 834            * try set next_state.
 835            */
 836           zlog_warn ("NSM[%s:%s]: %s (%s): "
 837                      "Warning: action tried to change next_state to %s",
 838                      IF_NAME (nbr->oi), inet_ntoa (nbr->router_id),
 839                      LOOKUP (ospf_nsm_state_msg, nbr->state),
 840                      ospf_nsm_event_str [event],
 841                      LOOKUP (ospf_nsm_state_msg, func_state));
 842         }
 843     }
 844
 845   assert (next_state != NSM_DependUpon);
 846
 847   /* If state is changed. */
 848   if (next_state != nbr->state)
 849     {
 850       nsm_notice_state_change (nbr, next_state, event);
 851 #ifdef HAVE_SNMP
 852       int send_trap_virt = 0;
 853       int send_trap = 0;
 854       /* Terminal state or regression */
 855       if ((next_state == NSM_Full)
 856               || (next_state == NSM_TwoWay)
 857               || (next_state < nbr->state))
 858       {
 859           /* ospfVirtNbrStateChange */
 860           if (nbr->oi->type == OSPF_IFTYPE_VIRTUALLINK)
 861               send_trap_virt = 1;
 862           /* ospfNbrStateChange trap  */
 863           else
 864               /* To/From FULL, only managed by DR */
 865               if (((next_state != NSM_Full) && (nbr->state != NSM_Full))
 866                       || (nbr->oi->state == ISM_DR))
 867                   send_trap = 1;
 868       }
 869 #endif
 870       nsm_change_state (nbr, next_state);
 871
 872 #ifdef HAVE_SNMP
 873       if (send_trap_virt) {
 874           ospfTrapVirtNbrStateChange(nbr);
 875       } else if (send_trap) {
 876           ospfTrapNbrStateChange(nbr);
 877       }
 878 #endif
 879     }
 880
 881   /* Make sure timer is set. */
 882   nsm_timer_set (nbr);
 883
 884   /* When event is NSM_KillNbr, InactivityTimer or LLDown, the neighbor
 885    * is deleted.
 886    *
 887    * Rather than encode knowledge here of which events lead to NBR
 888    * delete, we take our cue from the NSM table, via the dummy
 889    * 'Deleted' neighbour state.
 890    */
 891   if (nbr->state == NSM_Deleted)
 892     ospf_nbr_delete (nbr);
 893
 894   return 0;
 895 }
 896
 897 /* Check loading state. */
 898 void
 899 ospf_check_nbr_loading (struct ospf_neighbor *nbr)
 900 {
 901   if (nbr->state == NSM_Loading)
 902     {
 903       if (ospf_ls_request_isempty (nbr))
 904         OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_LoadingDone);
 905       else if (nbr->ls_req_last == NULL)
 906         ospf_ls_req_event (nbr);
 907     }
 908 }