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 static 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 static 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_DEBUG, "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 static 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 static int
 144 nsm_ignore (struct ospf_neighbor *nbr)
 145 {
 146   if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 147     zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: nsm_ignore called",
 148           IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));
 149
 150   return 0;
 151 }
 152
 153 static 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 static 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 static 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 static 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   /* Stay away from any Local Translated Type-7 LSAs */
 248   if (CHECK_FLAG (lsa->flags, OSPF_LSA_LOCAL_XLT))
 249     return 0;
 250
 251   if (IS_LSA_MAXAGE (lsa))
 252     ospf_ls_retransmit_add (nbr, lsa);
 253   else
 254     ospf_lsdb_add (&nbr->db_sum, lsa);
 255
 256   return 0;
 257 }
 258
 259 void
 260 ospf_db_summary_clear (struct ospf_neighbor *nbr)
 261 {
 262   struct ospf_lsdb *lsdb;
 263   int i;
 264
 265   lsdb = &nbr->db_sum;
 266   for (i = OSPF_MIN_LSA; i < OSPF_MAX_LSA; i++)
 267     {
 268       struct route_table *table = lsdb->type[i].db;
 269       struct route_node *rn;
 270
 271       for (rn = route_top (table); rn; rn = route_next (rn))
 272         if (rn->info)
 273           ospf_lsdb_delete (&nbr->db_sum, rn->info);
 274     }
 275 }
 276
 277 \f
 278
 279 /* The area link state database consists of the router-LSAs,
 280    network-LSAs and summary-LSAs contained in the area structure,
 281    along with the AS-external-LSAs contained in the global structure.
 282    AS-external-LSAs are omitted from a virtual neighbor's Database
 283    summary list.  AS-external-LSAs are omitted from the Database
 284    summary list if the area has been configured as a stub. */
 285 static int
 286 nsm_negotiation_done (struct ospf_neighbor *nbr)
 287 {
 288   struct ospf_area *area = nbr->oi->area;
 289   struct ospf_lsa *lsa;
 290   struct route_node *rn;
 291
 292   LSDB_LOOP (ROUTER_LSDB (area), rn, lsa)
 293     ospf_db_summary_add (nbr, lsa);
 294   LSDB_LOOP (NETWORK_LSDB (area), rn, lsa)
 295     ospf_db_summary_add (nbr, lsa);
 296   LSDB_LOOP (SUMMARY_LSDB (area), rn, lsa)
 297     ospf_db_summary_add (nbr, lsa);
 298   LSDB_LOOP (ASBR_SUMMARY_LSDB (area), rn, lsa)
 299     ospf_db_summary_add (nbr, lsa);
 300
 301 #ifdef HAVE_OPAQUE_LSA
 302   /* Process only if the neighbor is opaque capable. */
 303   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 304     {
 305       LSDB_LOOP (OPAQUE_LINK_LSDB (area), rn, lsa)
 306         ospf_db_summary_add (nbr, lsa);
 307       LSDB_LOOP (OPAQUE_AREA_LSDB (area), rn, lsa)
 308         ospf_db_summary_add (nbr, lsa);
 309     }
 310 #endif /* HAVE_OPAQUE_LSA */
 311
 312   if (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
 313       && area->external_routing == OSPF_AREA_DEFAULT)
 314     LSDB_LOOP (EXTERNAL_LSDB (nbr->oi->ospf), rn, lsa)
 315       ospf_db_summary_add (nbr, lsa);
 316
 317 #ifdef HAVE_OPAQUE_LSA
 318   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O)
 319       && (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
 320           && area->external_routing == OSPF_AREA_DEFAULT))
 321     LSDB_LOOP (OPAQUE_AS_LSDB (nbr->oi->ospf), rn, lsa)
 322       ospf_db_summary_add (nbr, lsa);
 323 #endif /* HAVE_OPAQUE_LSA */
 324
 325   return 0;
 326 }
 327
 328 static int
 329 nsm_exchange_done (struct ospf_neighbor *nbr)
 330 {
 331   if (ospf_ls_request_isempty (nbr))
 332     return NSM_Full;
 333
 334   /* Cancel dd retransmit timer. */
 335   /* OSPF_NSM_TIMER_OFF (nbr->t_db_desc); */
 336
 337   /* Send Link State Request. */
 338   ospf_ls_req_send (nbr);
 339
 340   return NSM_Loading;
 341 }
 342
 343 static int
 344 nsm_bad_ls_req (struct ospf_neighbor *nbr)
 345 {
 346   /* Clear neighbor. */
 347   nsm_reset_nbr (nbr);
 348
 349   return 0;
 350 }
 351
 352 static int
 353 nsm_adj_ok (struct ospf_neighbor *nbr)
 354 {
 355   struct ospf_interface *oi;
 356   int next_state;
 357   int flag = 0;
 358
 359   oi = nbr->oi;
 360   next_state = nbr->state;
 361
 362   /* These netowork types must be adjacency. */
 363   if (oi->type == OSPF_IFTYPE_POINTOPOINT
 364       || oi->type == OSPF_IFTYPE_POINTOMULTIPOINT
 365       || oi->type == OSPF_IFTYPE_VIRTUALLINK)
 366     flag = 1;
 367
 368   /* Router itself is the DRouter or the BDRouter. */
 369   if (IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi))
 370       || IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi)))
 371     flag = 1;
 372
 373   if (IPV4_ADDR_SAME (&nbr->address.u.prefix4, &DR (oi))
 374       || IPV4_ADDR_SAME (&nbr->address.u.prefix4, &BDR (oi)))
 375     flag = 1;
 376
 377   if (nbr->state == NSM_TwoWay && flag == 1)
 378     next_state = NSM_ExStart;
 379   else if (nbr->state >= NSM_ExStart && flag == 0)
 380     next_state = NSM_TwoWay;
 381
 382   return next_state;
 383 }
 384
 385 static int
 386 nsm_seq_number_mismatch (struct ospf_neighbor *nbr)
 387 {
 388   /* Clear neighbor. */
 389   nsm_reset_nbr (nbr);
 390
 391   return 0;
 392 }
 393
 394 static int
 395 nsm_oneway_received (struct ospf_neighbor *nbr)
 396 {
 397   /* Clear neighbor. */
 398   nsm_reset_nbr (nbr);
 399
 400   return 0;
 401 }
 402
 403 void
 404 nsm_reset_nbr (struct ospf_neighbor *nbr)
 405 {
 406   /* Clear Database Summary list. */
 407   if (!ospf_db_summary_isempty (nbr))
 408     ospf_db_summary_clear (nbr);
 409
 410   /* Clear Link State Request list. */
 411   if (!ospf_ls_request_isempty (nbr))
 412     ospf_ls_request_delete_all (nbr);
 413
 414   /* Clear Link State Retransmission list. */
 415   if (!ospf_ls_retransmit_isempty (nbr))
 416     ospf_ls_retransmit_clear (nbr);
 417
 418   /* Cancel thread. */
 419   OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
 420   OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
 421   OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
 422   OSPF_NSM_TIMER_OFF (nbr->t_hello_reply);
 423
 424 #ifdef HAVE_OPAQUE_LSA
 425   if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
 426     UNSET_FLAG (nbr->options, OSPF_OPTION_O);
 427 #endif /* HAVE_OPAQUE_LSA */
 428 }
 429
 430 static int
 431 nsm_kill_nbr (struct ospf_neighbor *nbr)
 432 {
 433   /* call it here because we cannot call it from ospf_nsm_event */
 434   nsm_change_state (nbr, NSM_Down);
 435
 436   /* Reset neighbor. */
 437   nsm_reset_nbr (nbr);
 438
 439   if (nbr->oi->type == OSPF_IFTYPE_NBMA && nbr->nbr_nbma != NULL)
 440     {
 441       struct ospf_nbr_nbma *nbr_nbma = nbr->nbr_nbma;
 442
 443       nbr_nbma->nbr = NULL;
 444       nbr_nbma->state_change = nbr->state_change;
 445
 446       nbr->nbr_nbma = NULL;
 447
 448       OSPF_POLL_TIMER_ON (nbr_nbma->t_poll, ospf_poll_timer,
 449                           nbr_nbma->v_poll);
 450
 451       if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 452         zlog_debug ("NSM[%s:%s]: Down (PollIntervalTimer scheduled)",
 453                    IF_NAME (nbr->oi), inet_ntoa (nbr->address.u.prefix4));
 454     }
 455
 456   /* Delete neighbor from interface. */
 457   ospf_nbr_delete (nbr);
 458
 459   return 0;
 460 }
 461
 462 static int
 463 nsm_inactivity_timer (struct ospf_neighbor *nbr)
 464 {
 465   /* Kill neighbor. */
 466   nsm_kill_nbr (nbr);
 467
 468   return 0;
 469 }
 470
 471 static int
 472 nsm_ll_down (struct ospf_neighbor *nbr)
 473 {
 474   /* Reset neighbor. */
 475   /*nsm_reset_nbr (nbr);*/
 476
 477   /* Kill neighbor. */
 478   nsm_kill_nbr (nbr);
 479
 480   return 0;
 481 }
 482
 483 /* Neighbor State Machine */
 484 struct {
 485   int (*func) (struct ospf_neighbor *);
 486   int next_state;
 487 } NSM [OSPF_NSM_STATE_MAX][OSPF_NSM_EVENT_MAX] =
 488 {
 489   {
 490     /* DependUpon: dummy state. */
 491     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 492     { nsm_ignore,              NSM_DependUpon }, /* HelloReceived     */
 493     { nsm_ignore,              NSM_DependUpon }, /* Start             */
 494     { nsm_ignore,              NSM_DependUpon }, /* 2-WayReceived     */
 495     { nsm_ignore,              NSM_DependUpon }, /* NegotiationDone   */
 496     { nsm_ignore,              NSM_DependUpon }, /* ExchangeDone      */
 497     { nsm_ignore,              NSM_DependUpon }, /* BadLSReq          */
 498     { nsm_ignore,              NSM_DependUpon }, /* LoadingDone       */
 499     { nsm_ignore,              NSM_DependUpon }, /* AdjOK?            */
 500     { nsm_ignore,              NSM_DependUpon }, /* SeqNumberMismatch */
 501     { nsm_ignore,              NSM_DependUpon }, /* 1-WayReceived     */
 502     { nsm_ignore,              NSM_DependUpon }, /* KillNbr           */
 503     { nsm_ignore,              NSM_DependUpon }, /* InactivityTimer   */
 504     { nsm_ignore,              NSM_DependUpon }, /* LLDown            */
 505   },
 506   {
 507     /* Down: */
 508     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 509     { nsm_hello_received,      NSM_Init       }, /* HelloReceived     */
 510     { nsm_start,               NSM_Attempt    }, /* Start             */
 511     { nsm_ignore,              NSM_Down       }, /* 2-WayReceived     */
 512     { nsm_ignore,              NSM_Down       }, /* NegotiationDone   */
 513     { nsm_ignore,              NSM_Down       }, /* ExchangeDone      */
 514     { nsm_ignore,              NSM_Down       }, /* BadLSReq          */
 515     { nsm_ignore,              NSM_Down       }, /* LoadingDone       */
 516     { nsm_ignore,              NSM_Down       }, /* AdjOK?            */
 517     { nsm_ignore,              NSM_Down       }, /* SeqNumberMismatch */
 518     { nsm_ignore,              NSM_Down       }, /* 1-WayReceived     */
 519     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 520     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 521     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 522   },
 523   {
 524     /* Attempt: */
 525     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 526     { nsm_hello_received,      NSM_Init       }, /* HelloReceived     */
 527     { nsm_ignore,              NSM_Attempt    }, /* Start             */
 528     { nsm_ignore,              NSM_Attempt    }, /* 2-WayReceived     */
 529     { nsm_ignore,              NSM_Attempt    }, /* NegotiationDone   */
 530     { nsm_ignore,              NSM_Attempt    }, /* ExchangeDone      */
 531     { nsm_ignore,              NSM_Attempt    }, /* BadLSReq          */
 532     { nsm_ignore,              NSM_Attempt    }, /* LoadingDone       */
 533     { nsm_ignore,              NSM_Attempt    }, /* AdjOK?            */
 534     { nsm_ignore,              NSM_Attempt    }, /* SeqNumberMismatch */
 535     { nsm_ignore,              NSM_Attempt    }, /* 1-WayReceived     */
 536     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 537     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 538     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 539   },
 540   {
 541     /* Init: */
 542     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 543     { nsm_hello_received,      NSM_Init       }, /* HelloReceived     */
 544     { nsm_ignore,              NSM_Init       }, /* Start             */
 545     { nsm_twoway_received,     NSM_DependUpon }, /* 2-WayReceived     */
 546     { nsm_ignore,              NSM_Init       }, /* NegotiationDone   */
 547     { nsm_ignore,              NSM_Init       }, /* ExchangeDone      */
 548     { nsm_ignore,              NSM_Init       }, /* BadLSReq          */
 549     { nsm_ignore,              NSM_Init       }, /* LoadingDone       */
 550     { nsm_ignore,              NSM_Init       }, /* AdjOK?            */
 551     { nsm_ignore,              NSM_Init       }, /* SeqNumberMismatch */
 552     { nsm_ignore,              NSM_Init       }, /* 1-WayReceived     */
 553     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 554     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 555     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 556   },
 557   {
 558     /* 2-Way: */
 559     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 560     { nsm_hello_received,      NSM_TwoWay     }, /* HelloReceived     */
 561     { nsm_ignore,              NSM_TwoWay     }, /* Start             */
 562     { nsm_ignore,              NSM_TwoWay     }, /* 2-WayReceived     */
 563     { nsm_ignore,              NSM_TwoWay     }, /* NegotiationDone   */
 564     { nsm_ignore,              NSM_TwoWay     }, /* ExchangeDone      */
 565     { nsm_ignore,              NSM_TwoWay     }, /* BadLSReq          */
 566     { nsm_ignore,              NSM_TwoWay     }, /* LoadingDone       */
 567     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 568     { nsm_ignore,              NSM_TwoWay     }, /* SeqNumberMismatch */
 569     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 570     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 571     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 572     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 573   },
 574   {
 575     /* ExStart: */
 576     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 577     { nsm_hello_received,      NSM_ExStart    }, /* HelloReceived     */
 578     { nsm_ignore,              NSM_ExStart    }, /* Start             */
 579     { nsm_ignore,              NSM_ExStart    }, /* 2-WayReceived     */
 580     { nsm_negotiation_done,    NSM_Exchange   }, /* NegotiationDone   */
 581     { nsm_ignore,              NSM_ExStart    }, /* ExchangeDone      */
 582     { nsm_ignore,              NSM_ExStart    }, /* BadLSReq          */
 583     { nsm_ignore,              NSM_ExStart    }, /* LoadingDone       */
 584     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 585     { nsm_ignore,              NSM_ExStart    }, /* SeqNumberMismatch */
 586     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 587     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 588     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 589     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 590   },
 591   {
 592     /* Exchange: */
 593     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 594     { nsm_hello_received,      NSM_Exchange   }, /* HelloReceived     */
 595     { nsm_ignore,              NSM_Exchange   }, /* Start             */
 596     { nsm_ignore,              NSM_Exchange   }, /* 2-WayReceived     */
 597     { nsm_ignore,              NSM_Exchange   }, /* NegotiationDone   */
 598     { nsm_exchange_done,       NSM_DependUpon }, /* ExchangeDone      */
 599     { nsm_bad_ls_req,          NSM_ExStart    }, /* BadLSReq          */
 600     { nsm_ignore,              NSM_Exchange   }, /* LoadingDone       */
 601     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 602     { nsm_seq_number_mismatch, NSM_ExStart    }, /* SeqNumberMismatch */
 603     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 604     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 605     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 606     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 607   },
 608   {
 609     /* Loading: */
 610     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 611     { nsm_hello_received,      NSM_Loading    }, /* HelloReceived     */
 612     { nsm_ignore,              NSM_Loading    }, /* Start             */
 613     { nsm_ignore,              NSM_Loading    }, /* 2-WayReceived     */
 614     { nsm_ignore,              NSM_Loading    }, /* NegotiationDone   */
 615     { nsm_ignore,              NSM_Loading    }, /* ExchangeDone      */
 616     { nsm_bad_ls_req,          NSM_ExStart    }, /* BadLSReq          */
 617     { nsm_ignore,              NSM_Full       }, /* LoadingDone       */
 618     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 619     { nsm_seq_number_mismatch, NSM_ExStart    }, /* SeqNumberMismatch */
 620     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 621     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 622     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 623     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 624   },
 625   { /* Full: */
 626     { nsm_ignore,              NSM_DependUpon }, /* NoEvent           */
 627     { nsm_hello_received,      NSM_Full       }, /* HelloReceived     */
 628     { nsm_ignore,              NSM_Full       }, /* Start             */
 629     { nsm_ignore,              NSM_Full       }, /* 2-WayReceived     */
 630     { nsm_ignore,              NSM_Full       }, /* NegotiationDone   */
 631     { nsm_ignore,              NSM_Full       }, /* ExchangeDone      */
 632     { nsm_bad_ls_req,          NSM_ExStart    }, /* BadLSReq          */
 633     { nsm_ignore,              NSM_Full       }, /* LoadingDone       */
 634     { nsm_adj_ok,              NSM_DependUpon }, /* AdjOK?            */
 635     { nsm_seq_number_mismatch, NSM_ExStart    }, /* SeqNumberMismatch */
 636     { nsm_oneway_received,     NSM_Init       }, /* 1-WayReceived     */
 637     { nsm_kill_nbr,            NSM_Down       }, /* KillNbr           */
 638     { nsm_inactivity_timer,    NSM_Down       }, /* InactivityTimer   */
 639     { nsm_ll_down,             NSM_Down       }, /* LLDown            */
 640   },
 641 };
 642
 643 const static char *ospf_nsm_event_str[] =
 644 {
 645   "NoEvent",
 646   "HelloReceived",
 647   "Start",
 648   "2-WayReceived",
 649   "NegotiationDone",
 650   "ExchangeDone",
 651   "BadLSReq",
 652   "LoadingDone",
 653   "AdjOK?",
 654   "SeqNumberMismatch",
 655   "1-WayReceived",
 656   "KillNbr",
 657   "InactivityTimer",
 658   "LLDown",
 659 };
 660
 661 void
 662 nsm_change_state (struct ospf_neighbor *nbr, int state)
 663 {
 664   struct ospf_interface *oi = nbr->oi;
 665   struct ospf_area *vl_area = NULL;
 666   u_char old_state;
 667   int x;
 668   int force = 1;
 669
 670   /* Logging change of status. */
 671   if (IS_DEBUG_OSPF (nsm, NSM_STATUS))
 672     zlog_debug ("NSM[%s:%s]: State change %s -> %s",
 673                IF_NAME (nbr->oi), inet_ntoa (nbr->router_id),
 674                LOOKUP (ospf_nsm_state_msg, nbr->state),
 675                LOOKUP (ospf_nsm_state_msg, state));
 676
 677   /* Preserve old status. */
 678   old_state = nbr->state;
 679
 680   /* Change to new status. */
 681   nbr->state = state;
 682
 683   /* Statistics. */
 684   nbr->state_change++;
 685
 686   if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
 687     vl_area = ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);
 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               if (x == ZEBRA_ROUTE_OSPF || x == ZEBRA_ROUTE_OSPF6)
 708                 continue;
 709               ospf_external_lsa_refresh_type (oi->ospf, x, force);
 710             }
 711         }
 712       else
 713         {
 714           oi->full_nbrs--;
 715           oi->area->full_nbrs--;
 716
 717           ospf_check_abr_status (oi->ospf);
 718
 719           if (oi->type == OSPF_IFTYPE_VIRTUALLINK && vl_area)
 720             if (vl_area->full_vls > 0)
 721               if (--vl_area->full_vls == 0)
 722                 ospf_schedule_abr_task (oi->ospf);
 723
 724           /* clear neighbor retransmit list */
 725           if (!ospf_ls_retransmit_isempty (nbr))
 726             ospf_ls_retransmit_clear (nbr);
 727         }
 728
 729       zlog_info ("nsm_change_state(%s, %s -> %s): "
 730                  "scheduling new router-LSA origination",
 731                  inet_ntoa (nbr->router_id),
 732                  LOOKUP(ospf_nsm_state_msg, old_state),
 733                  LOOKUP(ospf_nsm_state_msg, state));
 734
 735       ospf_router_lsa_timer_add (oi->area);
 736
 737       if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
 738         {
 739           struct ospf_area *vl_area =
 740             ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);
 741
 742           if (vl_area)
 743             ospf_router_lsa_timer_add (vl_area);
 744         }
 745
 746       /* Originate network-LSA. */
 747       if (oi->state == ISM_DR)
 748         {
 749           if (oi->network_lsa_self && oi->full_nbrs == 0)
 750             {
 751               ospf_lsa_flush_area (oi->network_lsa_self, oi->area);
 752               ospf_lsa_unlock (oi->network_lsa_self);
 753               oi->network_lsa_self = NULL;
 754               OSPF_TIMER_OFF (oi->t_network_lsa_self);
 755             }
 756           else
 757             ospf_network_lsa_timer_add (oi);
 758         }
 759     }
 760
 761 #ifdef HAVE_OPAQUE_LSA
 762   ospf_opaque_nsm_change (nbr, old_state);
 763 #endif /* HAVE_OPAQUE_LSA */
 764
 765   /* Start DD exchange protocol */
 766   if (state == NSM_ExStart)
 767     {
 768       if (nbr->dd_seqnum == 0)
 769         nbr->dd_seqnum = time (NULL);
 770       else
 771         nbr->dd_seqnum++;
 772
 773       nbr->dd_flags = OSPF_DD_FLAG_I|OSPF_DD_FLAG_M|OSPF_DD_FLAG_MS;
 774       ospf_db_desc_send (nbr);
 775     }
 776
 777   /* clear cryptographic sequence number */
 778   if (state == NSM_Down)
 779     nbr->crypt_seqnum = 0;
 780
 781   /* Generete NeighborChange ISM event. */
 782 #ifdef BUGGY_ISM_TRANSITION
 783   if ((old_state < NSM_TwoWay && state >= NSM_TwoWay) ||
 784       (old_state >= NSM_TwoWay && state < NSM_TwoWay))
 785     OSPF_ISM_EVENT_EXECUTE (oi, ISM_NeighborChange);
 786 #else /* BUGGY_ISM_TRANSITION */
 787   switch (oi->state) {
 788   case ISM_DROther:
 789   case ISM_Backup:
 790   case ISM_DR:
 791     if ((old_state < NSM_TwoWay && state >= NSM_TwoWay) ||
 792         (old_state >= NSM_TwoWay && state < NSM_TwoWay))
 793       OSPF_ISM_EVENT_EXECUTE (oi, ISM_NeighborChange);
 794     break;
 795   default:
 796     /* ISM_PointToPoint -> ISM_Down, ISM_Loopback -> ISM_Down, etc. */
 797     break;
 798   }
 799 #endif /* BUGGY_ISM_TRANSITION */
 800
 801   /* Performance hack. Send hello immideately when some neighbor enter
 802      Init state.  This whay we decrease neighbor discovery time. Gleb.*/
 803   if (state == NSM_Init)
 804     {
 805       OSPF_ISM_TIMER_OFF (oi->t_hello);
 806       OSPF_ISM_TIMER_ON (oi->t_hello, ospf_hello_timer, 1);
 807     }
 808
 809   /* Preserve old status? */
 810 }
 811
 812 /* Execute NSM event process. */
 813 int
 814 ospf_nsm_event (struct thread *thread)
 815 {
 816   int event;
 817   int next_state;
 818   struct ospf_neighbor *nbr;
 819   struct in_addr router_id;
 820   int old_state;
 821   struct ospf_interface *oi;
 822
 823   nbr = THREAD_ARG (thread);
 824   event = THREAD_VAL (thread);
 825   router_id = nbr->router_id;
 826
 827   old_state = nbr->state;
 828   oi = nbr->oi ;
 829
 830   /* Call function. */
 831   next_state = (*(NSM [nbr->state][event].func))(nbr);
 832
 833   /* When event is NSM_KillNbr or InactivityTimer, the neighbor is
 834      deleted. */
 835   if (event == NSM_KillNbr || event == NSM_InactivityTimer)
 836     {
 837       if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 838         zlog_debug ("NSM[%s:%s]: neighbor deleted",
 839                    IF_NAME (oi), inet_ntoa (router_id));
 840
 841       /* Timers are canceled in ospf_nbr_free, moreover we cannot call
 842          nsm_timer_set here because nbr is freed already!!!*/
 843       /*nsm_timer_set (nbr);*/
 844
 845       return 0;
 846     }
 847
 848   if (! next_state)
 849     next_state = NSM [nbr->state][event].next_state;
 850
 851   if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
 852     zlog_debug ("NSM[%s:%s]: %s (%s)", IF_NAME (oi),
 853                inet_ntoa (nbr->router_id),
 854                LOOKUP (ospf_nsm_state_msg, nbr->state),
 855                ospf_nsm_event_str [event]);
 856
 857   /* If state is changed. */
 858   if (next_state != nbr->state)
 859     nsm_change_state (nbr, next_state);
 860
 861   /* Make sure timer is set. */
 862   nsm_timer_set (nbr);
 863
 864   return 0;
 865 }
 866
 867 /* Check loading state. */
 868 void
 869 ospf_check_nbr_loading (struct ospf_neighbor *nbr)
 870 {
 871   if (nbr->state == NSM_Loading)
 872     {
 873       if (ospf_ls_request_isempty (nbr))
 874         OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_LoadingDone);
 875       else if (nbr->ls_req_last == NULL)
 876         ospf_ls_req_event (nbr);
 877     }
 878 }