ospf_nsm.c

router source code for the ospdf.

/*
 * OSPF version 2  Neighbor State Machine
 * From RFC2328 [OSPF Version 2]
 * Copyright (C) 1999, 2000 Toshiaki Takada
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <zebra.h>

#include "thread.h"
#include "memory.h"
#include "hash.h"
#include "linklist.h"
#include "prefix.h"
#include "if.h"
#include "table.h"
#include "stream.h"
#include "table.h"
#include "log.h"

#include "ospfd/ospfd.h"
#include "ospfd/ospf_interface.h"
#include "ospfd/ospf_ism.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_lsa.h"
#include "ospfd/ospf_lsdb.h"
#include "ospfd/ospf_neighbor.h"
#include "ospfd/ospf_nsm.h"
#include "ospfd/ospf_network.h"
#include "ospfd/ospf_packet.h"
#include "ospfd/ospf_dump.h"
#include "ospfd/ospf_flood.h"
#include "ospfd/ospf_abr.h"

void nsm_reset_nbr (struct ospf_neighbor *);


/* OSPF NSM Timer functions. */
int
ospf_inactivity_timer (struct thread *thread)
{
  struct ospf_neighbor *nbr;

  nbr = THREAD_ARG (thread);
  nbr->t_inactivity = NULL;

  if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))
    zlog (NULL, LOG_DEBUG, "NSM[%s:%s]: Timer (Inactivity timer expire)",
	  IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));

  OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_InactivityTimer);

  return 0;
}

int
ospf_db_desc_timer (struct thread *thread)
{
  struct ospf_interface *oi;
  struct ospf_neighbor *nbr;

  nbr = THREAD_ARG (thread);
  nbr->t_db_desc = NULL;

  oi = nbr->oi;

  if (IS_DEBUG_OSPF (nsm, NSM_TIMERS))
    zlog (NULL, LOG_INFO, "NSM[%s:%s]: Timer (DD Retransmit timer expire)",
	  IF_NAME (nbr->oi), inet_ntoa (nbr->src));

  /* resent last send DD packet. */
  assert (nbr->last_send);
  ospf_db_desc_resend (nbr);

  /* DD Retransmit timer set. */
  OSPF_NSM_TIMER_ON (nbr->t_db_desc, ospf_db_desc_timer, nbr->v_db_desc);

  return 0;
}

/* Hook function called after ospf NSM event is occured. */

void
nsm_timer_set (struct ospf_neighbor *nbr)
{
  switch (nbr->state)
    {
    case NSM_Down:
      OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
      break;
    case NSM_Attempt:
      OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
      break;
    case NSM_Init:
      OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
      break;
    case NSM_TwoWay:
      OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
      break;
    case NSM_ExStart:
      OSPF_NSM_TIMER_ON (nbr->t_db_desc, ospf_db_desc_timer, nbr->v_db_desc);
      OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
      break;
    case NSM_Exchange:
      OSPF_NSM_TIMER_ON (nbr->t_ls_upd, ospf_ls_upd_timer, nbr->v_ls_upd);
      if (!IS_SET_DD_MS (nbr->dd_flags))      
	OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      break;
    case NSM_Loading:
      OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      break;
    case NSM_Full:
      OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      break;
    default:
      OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
      break;
    }
}


/* OSPF NSM functions. */
int
nsm_ignore (struct ospf_neighbor *nbr)
{
  if (IS_DEBUG_OSPF (nsm, NSM_EVENTS))
    zlog (NULL, LOG_INFO, "NSM[%s:%s]: nsm_ignore called",
	  IF_NAME (nbr->oi), inet_ntoa (nbr->router_id));

  return 0;
}

int
nsm_hello_received (struct ospf_neighbor *nbr)
{
  /* Start or Restart Inactivity Timer. */
  OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
  
  OSPF_NSM_TIMER_ON (nbr->t_inactivity, ospf_inactivity_timer,
		     nbr->v_inactivity);

  if (nbr->oi->type == OSPF_IFTYPE_NBMA && nbr->nbr_nbma)
    OSPF_POLL_TIMER_OFF (nbr->nbr_nbma->t_poll);

  return 0;
}

int
nsm_start (struct ospf_neighbor *nbr)
{

  nsm_reset_nbr (nbr);

  if (nbr->nbr_nbma)
      OSPF_POLL_TIMER_OFF (nbr->nbr_nbma->t_poll);

  OSPF_NSM_TIMER_OFF (nbr->t_inactivity);
  
  OSPF_NSM_TIMER_ON (nbr->t_inactivity, ospf_inactivity_timer,
                     nbr->v_inactivity);

  return 0;
}

int
nsm_twoway_received (struct ospf_neighbor *nbr)
{
  struct ospf_interface *oi;
  int next_state = NSM_TwoWay;

  oi = nbr->oi;

  /* These netowork types must be adjacency. */
  if (oi->type == OSPF_IFTYPE_POINTOPOINT ||
      oi->type == OSPF_IFTYPE_POINTOMULTIPOINT ||
      oi->type == OSPF_IFTYPE_VIRTUALLINK)
    next_state = NSM_ExStart;

  /* Router itself is the DRouter or the BDRouter. */
  if (IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi)) ||
      IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi)))
    next_state = NSM_ExStart;

  /* Neighboring Router is the DRouter or the BDRouter. */
  if (IPV4_ADDR_SAME (&nbr->address.u.prefix4, &nbr->d_router) ||
      IPV4_ADDR_SAME (&nbr->address.u.prefix4, &nbr->bd_router))
    next_state = NSM_ExStart;

  return next_state;
}

int
ospf_db_summary_count (struct ospf_neighbor *nbr)
{
  return ospf_lsdb_count_all (&nbr->db_sum);
}

int
ospf_db_summary_isempty (struct ospf_neighbor *nbr)
{
  return ospf_lsdb_isempty (&nbr->db_sum);
}

int
ospf_db_summary_add (struct ospf_neighbor *nbr, struct ospf_lsa *lsa)
{
#ifdef HAVE_OPAQUE_LSA
  switch (lsa->data->type)
    {
    case OSPF_OPAQUE_LINK_LSA:
      /* Exclude type-9 LSAs that does not have the same "oi" with "nbr". */
      if (lsa->oi != nbr->oi)
          return 0;
      break;
    case OSPF_OPAQUE_AREA_LSA:
      /*
       * It is assured by the caller function "nsm_negotiation_done()"
       * that every given LSA belongs to the same area with "nbr".
       */
      break;
    case OSPF_OPAQUE_AS_LSA:
    default:
      break;
    }
#endif /* HAVE_OPAQUE_LSA */

#ifdef HAVE_NSSA
  /* Stay away from any Local Translated Type-7 LSAs */
  if (CHECK_FLAG (lsa->flags, OSPF_LSA_LOCAL_XLT))
    return 0;
#endif /* HAVE_NSSA */

  if (IS_LSA_MAXAGE (lsa))
    ospf_ls_retransmit_add (nbr, lsa);                      
  else 
    ospf_lsdb_add (&nbr->db_sum, lsa);

  return 0;
}

void
ospf_db_summary_clear (struct ospf_neighbor *nbr)
{
  struct ospf_lsdb *lsdb;
  int i;

  lsdb = &nbr->db_sum;
  for (i = OSPF_MIN_LSA; i < OSPF_MAX_LSA; i++)
    {
      struct route_table *table = lsdb->type[i].db;
      struct route_node *rn;

      for (rn = route_top (table); rn; rn = route_next (rn))
	if (rn->info)
	  ospf_lsdb_delete (&nbr->db_sum, rn->info);
    }
}



/* The area link state database consists of the router-LSAs,
   network-LSAs and summary-LSAs contained in the area structure,
   along with the AS-external-LSAs contained in the global structure.
   AS-external-LSAs are omitted from a virtual neighbor's Database
   summary list.  AS-external-LSAs are omitted from the Database
   summary list if the area has been configured as a stub. */
int
nsm_negotiation_done (struct ospf_neighbor *nbr)
{
  struct ospf_area *area = nbr->oi->area;
  struct ospf_lsa *lsa;
  struct route_node *rn;

  LSDB_LOOP (ROUTER_LSDB (area), rn, lsa)
    ospf_db_summary_add (nbr, lsa);
  LSDB_LOOP (NETWORK_LSDB (area), rn, lsa)
    ospf_db_summary_add (nbr, lsa);
  LSDB_LOOP (SUMMARY_LSDB (area), rn, lsa)
    ospf_db_summary_add (nbr, lsa);
  LSDB_LOOP (ASBR_SUMMARY_LSDB (area), rn, lsa)
    ospf_db_summary_add (nbr, lsa);

#ifdef HAVE_OPAQUE_LSA
  /* Process only if the neighbor is opaque capable. */
  if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
    {
      LSDB_LOOP (OPAQUE_LINK_LSDB (area), rn, lsa)
	ospf_db_summary_add (nbr, lsa);
      LSDB_LOOP (OPAQUE_AREA_LSDB (area), rn, lsa)
	ospf_db_summary_add (nbr, lsa);
    }
#endif /* HAVE_OPAQUE_LSA */

  if (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
      && area->external_routing == OSPF_AREA_DEFAULT)
    LSDB_LOOP (EXTERNAL_LSDB (nbr->oi->ospf), rn, lsa)
      ospf_db_summary_add (nbr, lsa);

#ifdef HAVE_OPAQUE_LSA
  if (CHECK_FLAG (nbr->options, OSPF_OPTION_O)
      && (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
	  && area->external_routing == OSPF_AREA_DEFAULT))
    LSDB_LOOP (OPAQUE_AS_LSDB (nbr->oi->ospf), rn, lsa)
      ospf_db_summary_add (nbr, lsa);
#endif /* HAVE_OPAQUE_LSA */

  return 0;
}

int
nsm_exchange_done (struct ospf_neighbor *nbr)
{
  if (ospf_ls_request_isempty (nbr))
    return NSM_Full;

  /* Cancel dd retransmit timer. */
  /* OSPF_NSM_TIMER_OFF (nbr->t_db_desc); */

  /* Send Link State Request. */
  ospf_ls_req_send (nbr);

  return NSM_Loading;
}

int
nsm_bad_ls_req (struct ospf_neighbor *nbr)
{
  /* Clear neighbor. */
  nsm_reset_nbr (nbr);

  return 0;
}

int
nsm_adj_ok (struct ospf_neighbor *nbr)
{
  struct ospf_interface *oi;
  int next_state;
  int flag = 0;

  oi = nbr->oi;
  next_state = nbr->state;

  /* These netowork types must be adjacency. */
  if (oi->type == OSPF_IFTYPE_POINTOPOINT
      || oi->type == OSPF_IFTYPE_POINTOMULTIPOINT
      || oi->type == OSPF_IFTYPE_VIRTUALLINK)
    flag = 1;

  /* Router itself is the DRouter or the BDRouter. */
  if (IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi))
      || IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi)))
    flag = 1;

  if (IPV4_ADDR_SAME (&nbr->address.u.prefix4, &DR (oi))
      || IPV4_ADDR_SAME (&nbr->address.u.prefix4, &BDR (oi)))
    flag = 1;

  if (nbr->state == NSM_TwoWay && flag == 1)
    next_state = NSM_ExStart;
  else if (nbr->state >= NSM_ExStart && flag == 0)
    next_state = NSM_TwoWay;

  return next_state;
}

int
nsm_seq_number_mismatch (struct ospf_neighbor *nbr)
{
  /* Clear neighbor. */
  nsm_reset_nbr (nbr);

  return 0;
}

int
nsm_oneway_received (struct ospf_neighbor *nbr)
{
  /* Clear neighbor. */
  nsm_reset_nbr (nbr);

  return 0;
}

void
nsm_reset_nbr (struct ospf_neighbor *nbr)
{
  /* Clear Database Summary list. */
  if (!ospf_db_summary_isempty (nbr))
    ospf_db_summary_clear (nbr);

  /* Clear Link State Request list. */
  if (!ospf_ls_request_isempty (nbr))
    ospf_ls_request_delete_all (nbr);

  /* Clear Link State Retransmission list. */
  if (!ospf_ls_retransmit_isempty (nbr))
    ospf_ls_retransmit_clear (nbr);

  /* Cancel thread. */
  OSPF_NSM_TIMER_OFF (nbr->t_db_desc);
  OSPF_NSM_TIMER_OFF (nbr->t_ls_req);
  OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);
  OSPF_NSM_TIMER_OFF (nbr->t_hello_reply);

#ifdef HAVE_OPAQUE_LSA
  if (CHECK_FLAG (nbr->options, OSPF_OPTION_O))
    UNSET_FLAG (nbr->options, OSPF_OPTION_O);
#endif /* HAVE_OPAQUE_LSA */
}

int
nsm_kill_nbr (struct ospf_neighbor *nbr)
{
  /* call it here because we cannot call it from ospf_nsm_event */
  nsm_change_state (nbr, NSM_Down);
  
  /* Reset neighbor. */
  nsm_reset_nbr (nbr);