ospf_abr.c

router source code for the ospdf.

/*
 * OSPF ABR functions.
 * Copyright (C) 1999, 2000 Alex Zinin, 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 "linklist.h"
#include "prefix.h"
#include "if.h"
#include "table.h"
#include "vty.h"
#include "filter.h"
#include "plist.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_spf.h"
#include "ospfd/ospf_route.h"
#include "ospfd/ospf_ia.h"
#include "ospfd/ospf_flood.h"
#include "ospfd/ospf_abr.h"
#include "ospfd/ospf_ase.h"
#include "ospfd/ospf_zebra.h"
#include "ospfd/ospf_dump.h"


struct ospf_area_range *
ospf_area_range_new (struct prefix_ipv4 *p)
{
  struct ospf_area_range *range;

  range = XCALLOC (MTYPE_OSPF_AREA_RANGE, sizeof (struct ospf_area_range));
  range->addr = p->prefix;
  range->masklen = p->prefixlen;
  range->cost_config = OSPF_AREA_RANGE_COST_UNSPEC;

  return range;
}

void
ospf_area_range_free (struct ospf_area_range *range)
{
  XFREE (MTYPE_OSPF_AREA_RANGE, range);
}

void
ospf_area_range_add (struct ospf_area *area, struct ospf_area_range *range)
{
  struct route_node *rn;
  struct prefix_ipv4 p;

  p.family = AF_INET;
  p.prefixlen = range->masklen;
  p.prefix = range->addr;

  rn = route_node_get (area->ranges, (struct prefix *)&p);
  if (rn->info)
    route_unlock_node (rn);
  else
    rn->info = range;
}

void
ospf_area_range_delete (struct ospf_area *area, struct ospf_area_range *range)
{
  struct route_node *rn;
  struct prefix_ipv4 p;

  p.family = AF_INET;
  p.prefixlen = range->masklen;
  p.prefix = range->addr;

  rn = route_node_lookup (area->ranges, (struct prefix *)&p);
  if (rn)
    {
      ospf_area_range_free (rn->info);
      rn->info = NULL;
      route_unlock_node (rn);
      route_unlock_node (rn);
    }
}

struct ospf_area_range *
ospf_area_range_lookup (struct ospf_area *area, struct prefix_ipv4 *p)
{
  struct route_node *rn;

  rn = route_node_lookup (area->ranges, (struct prefix *)p);
  if (rn)
    {
      route_unlock_node (rn);
      return rn->info;
    }
  return NULL;
}

struct ospf_area_range *
ospf_area_range_lookup_next (struct ospf_area *area, struct in_addr *range_net,
			     int first)
{
  struct route_node *rn;
  struct prefix_ipv4 p;
  struct ospf_area_range *find;

  p.family = AF_INET;
  p.prefixlen = IPV4_MAX_BITLEN;
  p.prefix = *range_net;

  if (first)
    rn = route_top (area->ranges);
  else
    {
      rn = route_node_get (area->ranges, (struct prefix *) &p);
      rn = route_next (rn);
    }

  for (; rn; rn = route_next (rn))
    if (rn->info)
      break;

  if (rn && rn->info)
    {
      find = rn->info;
      *range_net = rn->p.u.prefix4;
      route_unlock_node (rn);
      return find;
    }
  return NULL;
}

struct ospf_area_range *
ospf_area_range_match (struct ospf_area *area, struct prefix_ipv4 *p)
{
  struct route_node *node;

  node = route_node_match (area->ranges, (struct prefix *) p);
  if (node)
    {
      route_unlock_node (node);
      return node->info;
    }
  return NULL;
}

struct ospf_area_range *
ospf_area_range_match_any (struct ospf *ospf, struct prefix_ipv4 *p)
{
  struct ospf_area_range *range;
  listnode node;

  for (node = listhead (ospf->areas); node; nextnode (node))
    if ((range = ospf_area_range_match (node->data, p)))
      return range;

  return NULL;
}

int
ospf_area_range_active (struct ospf_area_range *range)
{
  return range->specifics;
}

int
ospf_area_actively_attached (struct ospf_area *area)
{
  return area->act_ints;
}

int
ospf_area_range_set (struct ospf *ospf, struct in_addr area_id,
		     struct prefix_ipv4 *p, int advertise)
{
  struct ospf_area *area;
  struct ospf_area_range *range;
  int ret = OSPF_AREA_ID_FORMAT_ADDRESS;

  area = ospf_area_get (ospf, area_id, ret);
  if (area == NULL)
    return 0;

  range = ospf_area_range_lookup (area, p);
  if (range != NULL)
    {
      if ((CHECK_FLAG (range->flags, OSPF_AREA_RANGE_ADVERTISE)
	   && !CHECK_FLAG (advertise, OSPF_AREA_RANGE_ADVERTISE))
	  || (!CHECK_FLAG (range->flags, OSPF_AREA_RANGE_ADVERTISE)
	      && CHECK_FLAG (advertise, OSPF_AREA_RANGE_ADVERTISE)))
	ospf_schedule_abr_task (ospf);
    }
  else
    {
      range = ospf_area_range_new (p);
      ospf_area_range_add (area, range);
      ospf_schedule_abr_task (ospf);
    }

  if (CHECK_FLAG (advertise, OSPF_AREA_RANGE_ADVERTISE))
    SET_FLAG (range->flags, OSPF_AREA_RANGE_ADVERTISE);
  else
    UNSET_FLAG (range->flags, OSPF_AREA_RANGE_ADVERTISE);

  return 1;
}

int
ospf_area_range_cost_set (struct ospf *ospf, struct in_addr area_id,
			  struct prefix_ipv4 *p, u_int32_t cost)
{
  struct ospf_area *area;
  struct ospf_area_range *range;
  int ret = OSPF_AREA_ID_FORMAT_ADDRESS;

  area = ospf_area_get (ospf, area_id, ret);
  if (area == NULL)
    return 0;

  range = ospf_area_range_new (p);
  if (range == NULL)
    return 0;

  if (range->cost_config != cost)
    {
      range->cost_config = cost;
      if (ospf_area_range_active (range))
	ospf_schedule_abr_task (ospf);
    }

  return 1;
}

int
ospf_area_range_unset (struct ospf *ospf, struct in_addr area_id,
		       struct prefix_ipv4 *p)
{
  struct ospf_area *area;
  struct ospf_area_range *range;

  area = ospf_area_lookup_by_area_id (ospf, area_id);
  if (area == NULL)
    return 0;

  range = ospf_area_range_lookup (area, p);
  if (range == NULL)
    return 0;

  if (ospf_area_range_active (range))
    ospf_schedule_abr_task (ospf);

  ospf_area_range_delete (area, range);

  return 1;
}

int
ospf_area_range_substitute_set (struct ospf *ospf, struct in_addr area_id,
				struct prefix_ipv4 *p, struct prefix_ipv4 *s)
{
  struct ospf_area *area;
  struct ospf_area_range *range;
  int ret = OSPF_AREA_ID_FORMAT_ADDRESS;

  area = ospf_area_get (ospf, area_id, ret);
  range = ospf_area_range_lookup (area, p);

  if (range != NULL)
    {
      if (!CHECK_FLAG (range->flags, OSPF_AREA_RANGE_ADVERTISE) ||
	  !CHECK_FLAG (range->flags, OSPF_AREA_RANGE_SUBSTITUTE))
	ospf_schedule_abr_task (ospf);
    }
  else
    {
      range = ospf_area_range_new (p);
      ospf_area_range_add (area, range);
      ospf_schedule_abr_task (ospf);
    }

  SET_FLAG (range->flags, OSPF_AREA_RANGE_ADVERTISE);
  SET_FLAG (range->flags, OSPF_AREA_RANGE_SUBSTITUTE);
  range->subst_addr = s->prefix;
  range->subst_masklen = s->prefixlen;

  return 1;
}

int
ospf_area_range_substitute_unset (struct ospf *ospf, struct in_addr area_id,
				  struct prefix_ipv4 *p)
{
  struct ospf_area *area;
  struct ospf_area_range *range;

  area = ospf_area_lookup_by_area_id (ospf, area_id);
  if (area == NULL)
    return 0;

  range = ospf_area_range_lookup (area, p);
  if (range == NULL)
    return 0;

  if (CHECK_FLAG (range->flags, OSPF_AREA_RANGE_SUBSTITUTE))
    if (ospf_area_range_active (range))
      ospf_schedule_abr_task (ospf);

  UNSET_FLAG (range->flags, OSPF_AREA_RANGE_SUBSTITUTE);
  range->subst_addr.s_addr = 0;
  range->subst_masklen = 0;

  return 1;
}

int
ospf_act_bb_connection (struct ospf *ospf)
{
  if (ospf->backbone == NULL)
    return 0;

  return ospf->backbone->full_nbrs;
}

/* Check area border router status. */
void
ospf_check_abr_status (struct ospf *ospf)
{
  struct ospf_area *area;
  listnode node;
  int bb_configured = 0;
  int bb_act_attached = 0;
  int areas_configured = 0;
  int areas_act_attached = 0;
  u_char new_flags = ospf->flags;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("ospf_check_abr_status(): Start");

  for (node = listhead (ospf->areas); node; nextnode (node))
    {
      area = getdata (node);

      if (listcount (area->oiflist)) 
	{
	  areas_configured++;
	  
	  if (OSPF_IS_AREA_BACKBONE (area))
 	    bb_configured = 1;
	}

      if (ospf_area_actively_attached (area))
	{
	  areas_act_attached++;
	  
	  if (OSPF_IS_AREA_BACKBONE (area))
            bb_act_attached = 1;
	}
    }

  if (IS_DEBUG_OSPF_EVENT)
    {
      zlog_info ("ospf_check_abr_status(): looked through areas");
      zlog_info ("ospf_check_abr_status(): bb_configured: %d", bb_configured);
      zlog_info ("ospf_check_abr_status(): bb_act_attached: %d",
		 bb_act_attached);
      zlog_info ("ospf_check_abr_status(): areas_configured: %d",
		 areas_configured);
      zlog_info ("ospf_check_abr_status(): areas_act_attached: %d",
		 areas_act_attached);
    }

  switch (ospf->abr_type)
    {
    case OSPF_ABR_SHORTCUT:
    case OSPF_ABR_STAND:
      if (areas_act_attached > 1)
	SET_FLAG (new_flags, OSPF_FLAG_ABR);
      else
	UNSET_FLAG (new_flags, OSPF_FLAG_ABR);
      break;

    case OSPF_ABR_IBM:
      if ((areas_act_attached > 1) && bb_configured)
	SET_FLAG (new_flags, OSPF_FLAG_ABR);
      else
	UNSET_FLAG (new_flags, OSPF_FLAG_ABR);
      break;

    case OSPF_ABR_CISCO:
      if ((areas_configured > 1) && bb_act_attached)
	SET_FLAG (new_flags, OSPF_FLAG_ABR);
      else
	UNSET_FLAG (new_flags, OSPF_FLAG_ABR);
      break;
    default:
      break;
    }

  if (new_flags != ospf->flags)
    {
      ospf_spf_calculate_schedule (ospf);
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_check_abr_status(): new router flags: %x",new_flags);
      ospf->flags = new_flags;
      OSPF_TIMER_ON (ospf->t_router_lsa_update,
		     ospf_router_lsa_update_timer, OSPF_LSA_UPDATE_DELAY);
    }
}

void
ospf_abr_update_aggregate (struct ospf_area_range *range,
			   struct ospf_route *or)
{
  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("ospf_abr_update_aggregate(): Start");

  if (range->cost_config != -1)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_abr_update_aggregate(): use configured cost %d",
		   range->cost_config);

      range->cost = range->cost_config;
    }
  else
    {
      if (range->specifics == 0)
	range->cost = or->cost; /* 1st time get 1st cost */

      if (or->cost < range->cost)
	{
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_abr_update_aggregate(): lowest cost, update");

	  range->cost = or->cost;
	}
    }

  range->specifics++;
}

static void
set_metric (struct ospf_lsa *lsa, u_int32_t metric)
{
  struct summary_lsa *header;
  u_char *mp;
  metric = htonl (metric);
  mp = (char *) &metric;
  mp++;
  header = (struct summary_lsa *) lsa->data;
  memcpy(header->metric, mp, 3);
}

#ifdef HAVE_NSSA
int
ospf_abr_check_nssa_range (struct prefix_ipv4 *p, u_int32_t cost,
			   struct ospf_area *area)
{
  /* The Type-7 is tested against the aggregated prefix and forwarded
     for lsa installation and flooding */
  return 0;
}

/* ospf_abr_translate_nssa */
int
ospf_abr_translate_nssa (struct ospf_area *area, struct ospf_lsa *lsa)
{
  /* Incoming Type-7 or later aggregated Type-7 

  LSA is skipped if P-bit is off.
  LSA is aggregated if within range.

  The Type-7 is translated, Installed/Approved as a Type-5 into
  global LSDB, then Flooded through AS

  Later, any Unapproved Translated Type-5's are flushed/discarded */

  struct ospf_lsa *dup;

  if (! CHECK_FLAG (lsa->data->options, OSPF_OPTION_NP))
    {
      if (IS_DEBUG_OSPF_NSSA)
	zlog_info ("ospf_abr_nssa(): P-bit off, NO Translation");
      return 0; 
    }

  if (IS_DEBUG_OSPF_NSSA)
    zlog_info ("ospf_abr_nssa(): TRANSLATING 7 to 5");

  /* No more P-bit. */
  /* UNSET_FLAG (lsa->data->options, OSPF_OPTION_NP); */

  /* Area where Aggregate testing will be inserted, just like summary
     advertisements */
  /* ospf_abr_check_nssa_range (p_arg, lsa-> cost, lsa -> area); */

  /* Follow thru here means no aggregation */
  dup = ospf_lsa_dup (lsa);	/* keep LSDB intact, lock = 1 */

  SET_FLAG (dup->flags, OSPF_LSA_LOCAL_XLT); /* Translated from 7  */
  SET_FLAG (dup->flags, OSPF_LSA_APPROVED); /* So, do not remove it */

  dup->data->type = OSPF_AS_EXTERNAL_LSA;  /* make Type-5 */

  ospf_lsa_checksum (dup->data);

  ospf_lsa_install (area->ospf, NULL, dup);  /* Install this Type-5 into LSDB, Lock = 2. */

  ospf_flood_through_as (area->ospf, NULL, dup); /* flood non-NSSA/STUB areas */
  
  /* This translated Type-5 will go to all non-NSSA areas connected to
     this ABR; The Type-5 could come from any of the NSSA's connected
     to this ABR.  */

  return 0;
}

void
ospf_abr_translate_nssa_range (struct prefix_ipv4 *p, u_int32_t cost)
{
  /* The Type-7 is created from the aggregated prefix and forwarded
     for lsa installation and flooding... to be added... */
}
#endif /* HAVE_NSSA */

void
ospf_abr_announce_network_to_area (struct prefix_ipv4 *p, u_int32_t cost,
				   struct ospf_area *area)
{
  struct ospf_lsa *lsa, *old = NULL;
  struct summary_lsa *sl = NULL;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("ospf_abr_announce_network_to_area(): Start");

  old = ospf_lsa_lookup_by_prefix (area->lsdb, OSPF_SUMMARY_LSA, p,
				   area->ospf->router_id);
  if (old)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_abr_announce_network_to_area(): old summary found");
      sl = (struct summary_lsa *) old->data;

      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_abr_announce_network_to_area(): "
		   "old metric: %d, new metric: %d",
		   GET_METRIC (sl->metric), cost);
    }

  if (old && (GET_METRIC (sl->metric) == cost))
    {