[mirror_frr.git] / ospfd / ospf_ia.c

/*
 * OSPF inter-area routing.
 * 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 "hash.h"
#include "linklist.h"
#include "prefix.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_spf.h"
#include "ospfd/ospf_route.h"
#include "ospfd/ospf_ase.h"
#include "ospfd/ospf_abr.h"
#include "ospfd/ospf_ia.h"
#include "ospfd/ospf_dump.h"

#define DEBUG

struct ospf_route *
ospf_find_abr_route (struct route_table *rtrs, 
                     struct prefix_ipv4 *abr,
                     struct ospf_area *area)
{
  struct route_node *rn;
  struct ospf_route *or;
  listnode node;

  if ((rn = route_node_lookup (rtrs, (struct prefix *) abr)) == NULL)
    return NULL;

  route_unlock_node (rn);

  for (node = listhead ((list) rn->info); node; nextnode (node))
    if ((or = getdata (node)) != NULL)
      if (IPV4_ADDR_SAME (&or->u.std.area_id, &area->area_id) && (or->u.std.flags & ROUTER_LSA_BORDER))
	return or;

  return NULL;
}

void
ospf_ia_network_route (struct ospf *ospf, struct route_table *rt,
		       struct prefix_ipv4 *p, struct ospf_route *new_or,
		       struct ospf_route *abr_or)
{
  struct route_node *rn1;
  struct ospf_route *or;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("ospf_ia_network_route(): processing summary route to %s/%d", 
	       inet_ntoa (p->prefix), p->prefixlen);

  /* Find a route to the same dest */
  if ((rn1 = route_node_lookup (rt, (struct prefix *) p)))
    {
      int res;

      route_unlock_node (rn1);

      if ((or = rn1->info))
	{
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_ia_network_route(): "
		       "Found a route to the same network");
	  /* Check the existing route. */
	  if ((res = ospf_route_cmp (ospf, new_or, or)) < 0)
	    {
	      /* New route is better, so replace old one. */
	      ospf_route_subst (rn1, new_or, abr_or);
	    }
	  else if (res == 0)
	    {
	      /* New and old route are equal, so next hops can be added. */
	      route_lock_node (rn1);
	      ospf_route_copy_nexthops (or, abr_or->paths);
	      route_unlock_node (rn1);

	      /* new route can be deleted, because existing route has been updated. */
	      ospf_route_free (new_or);
	    }
	  else
	    {
	      /* New route is worse, so free it. */
	      ospf_route_free (new_or);
	      return;
	    }
	} /* if (or)*/
    } /*if (rn1)*/
  else
    { /* no route */
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_ia_network_route(): add new route to %s/%d",
		   inet_ntoa (p->prefix), p->prefixlen);
      ospf_route_add (rt, p, new_or, abr_or);
    }
}

void
ospf_ia_router_route (struct ospf *ospf, struct route_table *rtrs,
		      struct prefix_ipv4 *p,
                      struct ospf_route *new_or, struct ospf_route *abr_or)
{
  struct ospf_route *or = NULL;
  struct route_node *rn;
  int ret;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("ospf_ia_router_route(): considering %s/%d", 
	       inet_ntoa (p->prefix), p->prefixlen);
  /* Find a route to the same dest */
  rn = route_node_get (rtrs, (struct prefix *) p);
   
  if (rn->info == NULL)
    /* This is a new route */
    rn->info = list_new ();
  else
    {
      struct ospf_area *or_area;
      or_area = ospf_area_lookup_by_area_id (ospf, new_or->u.std.area_id);
      assert (or_area);
      /* This is an additional route */
      route_unlock_node (rn);
      or = ospf_find_asbr_route_through_area (rtrs, p, or_area);
    }

  if (or)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_ia_router_route(): "
		   "a route to the same ABR through the same area exists");
      /* New route is better */
      if ((ret = ospf_route_cmp (ospf, new_or, or)) < 0)
	{
	  listnode_delete (rn->info, or);
	  ospf_route_free (or);
	  /* proceed down */
	}
      /* Routes are the same */
      else if (ret == 0)
	{
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_ia_router_route(): merging the new route");

	  ospf_route_copy_nexthops (or, abr_or->paths);
	  ospf_route_free (new_or);
	  return;
	}
      /* New route is worse */
      else
	{
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_ia_router_route(): skipping the new route");
	  ospf_route_free (new_or);
	  return;
	}
    }

  ospf_route_copy_nexthops (new_or, abr_or->paths);

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("ospf_ia_router_route(): adding the new route"); 

  listnode_add (rn->info, new_or);
}

\f
int
process_summary_lsa (struct ospf_area *area, struct route_table *rt,
		     struct route_table *rtrs, struct ospf_lsa *lsa)
{
  struct ospf *ospf = area->ospf;
  struct ospf_area_range *range;
  struct ospf_route *abr_or, *new_or;
  struct summary_lsa *sl;
  struct prefix_ipv4 p, abr;
  u_int32_t metric;

  if (lsa == NULL)
    return 0;

  sl = (struct summary_lsa *) lsa->data;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("process_summary_lsa(): LS ID: %s", inet_ntoa (sl->header.id));

  metric = GET_METRIC (sl->metric);
   
  if (metric == OSPF_LS_INFINITY)
    return 0;

  if (IS_LSA_MAXAGE (lsa))
    return 0;

  if (ospf_lsa_is_self_originated (area->ospf, lsa))
    return 0;

  p.family = AF_INET;
  p.prefix = sl->header.id;
   
  if (sl->header.type == OSPF_SUMMARY_LSA)
    p.prefixlen = ip_masklen (sl->mask);
  else
    p.prefixlen = IPV4_MAX_BITLEN;
      
  apply_mask_ipv4 (&p);

  if (sl->header.type == OSPF_SUMMARY_LSA &&
      (range = ospf_area_range_match_any (ospf, &p)) &&
      ospf_area_range_active (range))
    return 0;

  if (ospf->abr_type != OSPF_ABR_STAND &&
      area->external_routing != OSPF_AREA_DEFAULT &&
      p.prefix.s_addr == OSPF_DEFAULT_DESTINATION &&
      p.prefixlen == 0)
    return 0; /* Ignore summary default from a stub area */

  abr.family = AF_INET;
  abr.prefix = sl->header.adv_router;
  abr.prefixlen = IPV4_MAX_BITLEN;
  apply_mask_ipv4 (&abr);

  abr_or = ospf_find_abr_route (rtrs, &abr, area);

  if (abr_or == NULL)
    return 0;

  new_or = ospf_route_new ();
  new_or->type = OSPF_DESTINATION_NETWORK;
  new_or->id = sl->header.id;
  new_or->mask = sl->mask;
  new_or->u.std.options = sl->header.options;
  new_or->u.std.origin = (struct lsa_header *) sl;
  new_or->cost = abr_or->cost + metric;
  new_or->u.std.area_id = area->area_id;
  new_or->u.std.external_routing = area->external_routing;
  new_or->path_type = OSPF_PATH_INTER_AREA;

  if (sl->header.type == OSPF_SUMMARY_LSA)
    ospf_ia_network_route (ospf, rt, &p, new_or, abr_or);
  else 
    {
      new_or->type = OSPF_DESTINATION_ROUTER;
      new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
      ospf_ia_router_route (ospf, rtrs, &p, new_or, abr_or);
    }

  return 0;
}

void
ospf_examine_summaries (struct ospf_area *area,
			struct route_table *lsdb_rt,
                        struct route_table *rt,
                        struct route_table *rtrs)
{
  struct ospf_lsa *lsa;
  struct route_node *rn;

  LSDB_LOOP (lsdb_rt, rn, lsa)
    process_summary_lsa (area, rt, rtrs, lsa);
}

int
ospf_area_is_transit (struct ospf_area *area)
{
  return (area->transit == OSPF_TRANSIT_TRUE) ||
    ospf_full_virtual_nbrs(area); /* Cisco forgets to set the V-bit :( */
}

void
ospf_update_network_route (struct ospf *ospf,
			   struct route_table *rt, 
                           struct route_table *rtrs,
                           struct summary_lsa *lsa,
                           struct prefix_ipv4 *p,
                           struct ospf_area *area)
{
  struct route_node *rn;
  struct ospf_route *or, *abr_or, *new_or;
  struct prefix_ipv4 abr;
  u_int32_t cost;

  abr.family = AF_INET;
  abr.prefix =lsa->header.adv_router;
  abr.prefixlen = IPV4_MAX_BITLEN;
  apply_mask_ipv4 (&abr);

  abr_or = ospf_find_abr_route (rtrs, &abr, area);

  if (abr_or == NULL)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_update_network_route(): can't find a route to the ABR");
      return;
    }

  cost = abr_or->cost + GET_METRIC (lsa->metric);

  rn = route_node_lookup (rt, (struct prefix *) p);

  if (! rn)
    {
      if (ospf->abr_type != OSPF_ABR_SHORTCUT)
        return; /* Standard ABR can update only already installed
                   backbone paths                                       */
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_update_network_route(): "
		   "Allowing Shortcut ABR to add new route");
      new_or = ospf_route_new ();
      new_or->type = OSPF_DESTINATION_NETWORK;
      new_or->id = lsa->header.id;
      new_or->mask = lsa->mask;
      new_or->u.std.options = lsa->header.options;
      new_or->u.std.origin = (struct lsa_header *) lsa;
      new_or->cost = cost;
      new_or->u.std.area_id = area->area_id;
      new_or->u.std.external_routing = area->external_routing;
      new_or->path_type = OSPF_PATH_INTER_AREA;
      ospf_route_add (rt, p, new_or, abr_or);

      return;
    }
  else
    {
      route_unlock_node (rn);
      if (rn->info == NULL)
        return;
    }

  or = rn->info;

  if (or->path_type != OSPF_PATH_INTRA_AREA &&
      or->path_type != OSPF_PATH_INTER_AREA)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_update_network_route(): ERR: path type is wrong");
      return;
    }

  if (ospf->abr_type == OSPF_ABR_SHORTCUT)
    {
      if (or->path_type == OSPF_PATH_INTRA_AREA &&
	  !OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
	{
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_update_network_route(): Shortcut: "
		       "this intra-area path is not backbone");
	  return;
	}
    }
  else   /* Not Shortcut ABR */
    {
      if (!OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
	{
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_update_network_route(): "
		       "route is not BB-associated");
	  return; /* We can update only BB routes */
	}
    }

  if (or->cost < cost)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_update_network_route(): new route is worse");
      return;
    }

  if (or->cost == cost)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_update_network_route(): "
		   "new route is same distance, adding nexthops");
      ospf_route_copy_nexthops (or, abr_or->paths);
    }

  if (or->cost > cost)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_update_network_route(): "
		   "new route is better, overriding nexthops");
      ospf_route_subst_nexthops (or, abr_or->paths);
      or->cost = cost;

      if ((ospf->abr_type == OSPF_ABR_SHORTCUT) &&
	  !OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
	{
	  or->path_type = OSPF_PATH_INTER_AREA;
	  or->u.std.area_id = area->area_id;
	  or->u.std.external_routing = area->external_routing;
          /* Note that we can do this only in Shortcut ABR mode,
             because standard ABR must leave the route type and area
             unchanged
          */
        }
    }
}

void
ospf_update_router_route (struct ospf *ospf,
			  struct route_table *rtrs, 
                          struct summary_lsa *lsa,
                          struct prefix_ipv4 *p,
                          struct ospf_area *area)
{
  struct ospf_route *or, *abr_or, *new_or;
  struct prefix_ipv4 abr;
  u_int32_t cost;

  abr.family = AF_INET;
  abr.prefix = lsa->header.adv_router;
  abr.prefixlen = IPV4_MAX_BITLEN;
  apply_mask_ipv4 (&abr);

  abr_or = ospf_find_abr_route (rtrs, &abr, area);

  if (abr_or == NULL)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_update_router_route(): can't find a route to the ABR");
      return;
    }

  cost = abr_or->cost + GET_METRIC (lsa->metric);

  /* First try to find a backbone path,
     because standard ABR can update only BB-associated paths */

  if ((ospf->backbone == NULL) &&
      (ospf->abr_type != OSPF_ABR_SHORTCUT))

     /* no BB area, not Shortcut ABR, exiting */
     return;
 
  or = ospf_find_asbr_route_through_area (rtrs, p, ospf->backbone);

  if (or == NULL)
    {
      if (ospf->abr_type != OSPF_ABR_SHORTCUT)

         /* route to ASBR through the BB not found
            the router is not Shortcut ABR, exiting */

          return;
      else
	/* We're a Shortcut ABR*/
	{
	  /* Let it either add a new router or update the route
	     through the same (non-BB) area. */

	  new_or = ospf_route_new ();
	  new_or->type = OSPF_DESTINATION_ROUTER;
	  new_or->id = lsa->header.id;
	  new_or->mask = lsa->mask;
	  new_or->u.std.options = lsa->header.options;
	  new_or->u.std.origin = (struct lsa_header *)lsa;
	  new_or->cost = cost;
	  new_or->u.std.area_id = area->area_id;
	  new_or->u.std.external_routing = area->external_routing;
	  new_or->path_type = OSPF_PATH_INTER_AREA;
	  new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
	  ospf_ia_router_route (ospf, rtrs, p, new_or, abr_or);

          return;
        }
    }

  /* At this point the "or" is always bb-associated */

  if (!(or->u.std.flags & ROUTER_LSA_EXTERNAL))
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_upd_router_route(): the remote router is not an ASBR");
      return;
    }

  if (or->path_type != OSPF_PATH_INTRA_AREA &&
      or->path_type != OSPF_PATH_INTER_AREA)
    return;

  if (or->cost < cost)
    return;

  else if (or->cost == cost)
    ospf_route_copy_nexthops (or, abr_or->paths);

  else if (or->cost > cost)
    {
      ospf_route_subst_nexthops (or, abr_or->paths);
      or->cost = cost;

      /* Even if the ABR runs in Shortcut mode, we can't change
         the path type and area, because the "or" is always bb-associated
         at this point and even Shortcut ABR can't change these attributes */
    }
}

int
process_transit_summary_lsa (struct ospf_area *area, struct route_table *rt,
			     struct route_table *rtrs, struct ospf_lsa *lsa)
{
  struct ospf *ospf = area->ospf;
  struct summary_lsa *sl;
  struct prefix_ipv4 p;
  u_int32_t metric;

  if (lsa == NULL)
    return 0;

  sl = (struct summary_lsa *) lsa->data;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("process_transit_summaries(): LS ID: %s",
	       inet_ntoa (lsa->data->id));
  metric = GET_METRIC (sl->metric);
   
  if (metric == OSPF_LS_INFINITY)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("process_transit_summaries(): metric is infinity, skip");
      return 0;
    }

  if (IS_LSA_MAXAGE (lsa))
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("process_transit_summaries(): This LSA is too old");
      return 0;
    }

  if (ospf_lsa_is_self_originated (area->ospf, lsa))
    { 
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("process_transit_summaries(): This LSA is mine, skip");
      return 0;
    }

  p.family = AF_INET;
  p.prefix = sl->header.id;
   
  if (sl->header.type == OSPF_SUMMARY_LSA)
    p.prefixlen = ip_masklen (sl->mask);
  else
    p.prefixlen = IPV4_MAX_BITLEN;
      
  apply_mask_ipv4 (&p);

  if (sl->header.type == OSPF_SUMMARY_LSA)
    ospf_update_network_route (ospf, rt, rtrs, sl, &p, area);
  else
    ospf_update_router_route (ospf, rtrs, sl, &p, area);
 
  return 0;
}

void
ospf_examine_transit_summaries (struct ospf_area *area,
				struct route_table *lsdb_rt,
                                struct route_table *rt,
                                struct route_table *rtrs)
{
  struct ospf_lsa *lsa;
  struct route_node *rn;

  LSDB_LOOP (lsdb_rt, rn, lsa)
    process_transit_summary_lsa (area, rt, rtrs, lsa);
}

void
ospf_ia_routing (struct ospf *ospf,
		 struct route_table *rt,
                 struct route_table *rtrs)
{
  struct ospf_area * area;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("ospf_ia_routing():start");

  if (IS_OSPF_ABR (ospf))
    {
      listnode node; 
      struct ospf_area *area;

      switch (ospf->abr_type)
        {
        case OSPF_ABR_STAND:
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_ia_routing():Standard ABR");

          if ((area = ospf->backbone))
            {
              listnode node;

	      if (IS_DEBUG_OSPF_EVENT)
		{
		  zlog_info ("ospf_ia_routing():backbone area found");
		  zlog_info ("ospf_ia_routing():examining summaries");
		}

              OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);

	      for (node = listhead (ospf->areas); node; nextnode (node))
                if ((area = getdata (node)) != NULL)
                  if (area != ospf->backbone)
		    if (ospf_area_is_transit (area))
		      OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
            }
          else
	    if (IS_DEBUG_OSPF_EVENT)
	      zlog_info ("ospf_ia_routing():backbone area NOT found");
          break;
        case OSPF_ABR_IBM:
        case OSPF_ABR_CISCO:
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_ia_routing():Alternative Cisco/IBM ABR");
          area = ospf->backbone; /* Find the BB */

          /* If we have an active BB connection */
          if (area && ospf_act_bb_connection (ospf))
            {
	      if (IS_DEBUG_OSPF_EVENT)
		{
		  zlog_info ("ospf_ia_routing(): backbone area found");
		  zlog_info ("ospf_ia_routing(): examining BB summaries");
		}

              OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);

	      for (node = listhead (ospf->areas); node; nextnode (node))
                if ((area = getdata (node)) != NULL)
                  if (area != ospf->backbone)
		    if (ospf_area_is_transit (area))
		      OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
            }
          else
            { /* No active BB connection--consider all areas */
	      if (IS_DEBUG_OSPF_EVENT)
		zlog_info ("ospf_ia_routing(): "
			   "Active BB connection not found");
	      for (node = listhead (ospf->areas); node; nextnode (node))
                if ((area = getdata (node)) != NULL)
                  OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
            }
          break;
        case OSPF_ABR_SHORTCUT:
	  if (IS_DEBUG_OSPF_EVENT)
	    zlog_info ("ospf_ia_routing():Alternative Shortcut");
          area = ospf->backbone; /* Find the BB */

          /* If we have an active BB connection */
          if (area && ospf_act_bb_connection (ospf))
            {
	      if (IS_DEBUG_OSPF_EVENT)
		{
		  zlog_info ("ospf_ia_routing(): backbone area found");
		  zlog_info ("ospf_ia_routing(): examining BB summaries");
		}
              OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
            }

	  for (node = listhead (ospf->areas); node; nextnode (node))
            if ((area = getdata (node)) != NULL)
              if (area != ospf->backbone)
		if (ospf_area_is_transit (area) ||
		    ((area->shortcut_configured != OSPF_SHORTCUT_DISABLE) &&
		     ((ospf->backbone == NULL) ||
                      ((area->shortcut_configured == OSPF_SHORTCUT_ENABLE) &&
		       area->shortcut_capability))))
		  OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
          break;
        default:
          break;
        }
    }
  else 
    {
      listnode node;

      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("ospf_ia_routing():not ABR, considering all areas");

      for (node = listhead (ospf->areas); node; nextnode (node))
        if ((area = getdata (node)) != NULL)
          OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
    }
}
Commit	Line	Data
718e3744	1	/*
	2	* OSPF inter-area routing.
	3	* Copyright (C) 1999, 2000 Alex Zinin, Toshiaki Takada
	4	*
	5	* This file is part of GNU Zebra.
	6	*
	7	* GNU Zebra is free software; you can redistribute it and/or modify it
	8	* under the terms of the GNU General Public License as published by the
	9	* Free Software Foundation; either version 2, or (at your option) any
	10	* later version.
	11	*
	12	* GNU Zebra is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with GNU Zebra; see the file COPYING. If not, write to the Free
	19	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
	20	* 02111-1307, USA.
	21	*/
	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 "table.h"
	32	#include "log.h"
	33
	34	#include "ospfd/ospfd.h"
	35	#include "ospfd/ospf_interface.h"
	36	#include "ospfd/ospf_ism.h"
	37	#include "ospfd/ospf_asbr.h"
	38	#include "ospfd/ospf_lsa.h"
	39	#include "ospfd/ospf_lsdb.h"
	40	#include "ospfd/ospf_neighbor.h"
	41	#include "ospfd/ospf_nsm.h"
	42	#include "ospfd/ospf_spf.h"
	43	#include "ospfd/ospf_route.h"
	44	#include "ospfd/ospf_ase.h"
	45	#include "ospfd/ospf_abr.h"
	46	#include "ospfd/ospf_ia.h"
	47	#include "ospfd/ospf_dump.h"
	48
	49	#define DEBUG
	50
	51	struct ospf_route *
	52	ospf_find_abr_route (struct route_table *rtrs,
	53	struct prefix_ipv4 *abr,
	54	struct ospf_area *area)
	55	{
	56	struct route_node *rn;
	57	struct ospf_route *or;
	58	listnode node;
	59
	60	if ((rn = route_node_lookup (rtrs, (struct prefix *) abr)) == NULL)
	61	return NULL;
	62
	63	route_unlock_node (rn);
	64
65	for (node = listhead ((list) rn->info); node; nextnode (node))
66	if ((or = getdata (node)) != NULL)
67	if (IPV4_ADDR_SAME (&or->u.std.area_id, &area->area_id) && (or->u.std.flags & ROUTER_LSA_BORDER))
68	return or;
69
70	return NULL;
71	}
72
73	void
96735eea	74	ospf_ia_network_route (struct ospf ospf, struct route_table rt,
	75	struct prefix_ipv4 p, struct ospf_route new_or,
	76	struct ospf_route *abr_or)
718e3744	77	{
	78	struct route_node *rn1;
	79	struct ospf_route *or;
	80
	81	if (IS_DEBUG_OSPF_EVENT)
	82	zlog_info ("ospf_ia_network_route(): processing summary route to %s/%d",
	83	inet_ntoa (p->prefix), p->prefixlen);
	84
	85	/* Find a route to the same dest */
	86	if ((rn1 = route_node_lookup (rt, (struct prefix *) p)))
	87	{
	88	int res;
	89
	90	route_unlock_node (rn1);
	91
	92	if ((or = rn1->info))
	93	{
	94	if (IS_DEBUG_OSPF_EVENT)
	95	zlog_info ("ospf_ia_network_route(): "
	96	"Found a route to the same network");
	97	/* Check the existing route. */
96735eea	98	if ((res = ospf_route_cmp (ospf, new_or, or)) < 0)
718e3744	99	{
	100	/* New route is better, so replace old one. */
	101	ospf_route_subst (rn1, new_or, abr_or);
	102	}
	103	else if (res == 0)
	104	{
	105	/* New and old route are equal, so next hops can be added. */
	106	route_lock_node (rn1);
96735eea	107	ospf_route_copy_nexthops (or, abr_or->paths);
718e3744	108	route_unlock_node (rn1);
	109
	110	/* new route can be deleted, because existing route has been updated. */
	111	ospf_route_free (new_or);
	112	}
	113	else
	114	{
	115	/* New route is worse, so free it. */
	116	ospf_route_free (new_or);
	117	return;
	118	}
	119	} /* if (or)*/
	120	} /if (rn1)/
	121	else
	122	{ /* no route */
	123	if (IS_DEBUG_OSPF_EVENT)
	124	zlog_info ("ospf_ia_network_route(): add new route to %s/%d",
	125	inet_ntoa (p->prefix), p->prefixlen);
	126	ospf_route_add (rt, p, new_or, abr_or);
	127	}
	128	}
	129
	130	void
96735eea	131	ospf_ia_router_route (struct ospf ospf, struct route_table rtrs,
96735eea	132	struct prefix_ipv4 *p,
718e3744	133	struct ospf_route new_or, struct ospf_route abr_or)
718e3744	134	{
718e3744	135	struct ospf_route *or = NULL;
96735eea	136	struct route_node *rn;
718e3744	137	int ret;
	138
	139	if (IS_DEBUG_OSPF_EVENT)
	140	zlog_info ("ospf_ia_router_route(): considering %s/%d",
	141	inet_ntoa (p->prefix), p->prefixlen);
	142	/* Find a route to the same dest */
96735eea	143	rn = route_node_get (rtrs, (struct prefix *) p);
718e3744	144
	145	if (rn->info == NULL)
	146	/* This is a new route */
	147	rn->info = list_new ();
	148	else
	149	{
	150	struct ospf_area *or_area;
96735eea	151	or_area = ospf_area_lookup_by_area_id (ospf, new_or->u.std.area_id);
718e3744	152	assert (or_area);
	153	/* This is an additional route */
	154	route_unlock_node (rn);
96735eea	155	or = ospf_find_asbr_route_through_area (rtrs, p, or_area);
718e3744	156	}
	157
	158	if (or)
	159	{
	160	if (IS_DEBUG_OSPF_EVENT)
	161	zlog_info ("ospf_ia_router_route(): "
	162	"a route to the same ABR through the same area exists");
	163	/* New route is better */
96735eea	164	if ((ret = ospf_route_cmp (ospf, new_or, or)) < 0)
718e3744	165	{
	166	listnode_delete (rn->info, or);
	167	ospf_route_free (or);
	168	/* proceed down */
	169	}
	170	/* Routes are the same */
	171	else if (ret == 0)
	172	{
	173	if (IS_DEBUG_OSPF_EVENT)
	174	zlog_info ("ospf_ia_router_route(): merging the new route");
	175
96735eea	176	ospf_route_copy_nexthops (or, abr_or->paths);
718e3744	177	ospf_route_free (new_or);
	178	return;
	179	}
	180	/* New route is worse */
	181	else
	182	{
	183	if (IS_DEBUG_OSPF_EVENT)
	184	zlog_info ("ospf_ia_router_route(): skipping the new route");
	185	ospf_route_free (new_or);
	186	return;
	187	}
	188	}
	189
96735eea	190	ospf_route_copy_nexthops (new_or, abr_or->paths);
718e3744	191
	192	if (IS_DEBUG_OSPF_EVENT)
	193	zlog_info ("ospf_ia_router_route(): adding the new route");
	194
	195	listnode_add (rn->info, new_or);
	196	}
	197
	198	\f
718e3744	199	int
96735eea	200	process_summary_lsa (struct ospf_area area, struct route_table rt,
96735eea	201	struct route_table rtrs, struct ospf_lsa lsa)
718e3744	202	{
96735eea	203	struct ospf *ospf = area->ospf;
718e3744	204	struct ospf_area_range *range;
	205	struct ospf_route abr_or, new_or;
	206	struct summary_lsa *sl;
	207	struct prefix_ipv4 p, abr;
	208	u_int32_t metric;
718e3744	209
96735eea	210	if (lsa == NULL)
718e3744	211	return 0;
718e3744	212
96735eea	213	sl = (struct summary_lsa *) lsa->data;
718e3744	214
	215	if (IS_DEBUG_OSPF_EVENT)
	216	zlog_info ("process_summary_lsa(): LS ID: %s", inet_ntoa (sl->header.id));
	217
	218	metric = GET_METRIC (sl->metric);
	219
	220	if (metric == OSPF_LS_INFINITY)
	221	return 0;
	222
96735eea	223	if (IS_LSA_MAXAGE (lsa))
718e3744	224	return 0;
718e3744	225
96735eea	226	if (ospf_lsa_is_self_originated (area->ospf, lsa))
718e3744	227	return 0;
	228
	229	p.family = AF_INET;
	230	p.prefix = sl->header.id;
	231
	232	if (sl->header.type == OSPF_SUMMARY_LSA)
	233	p.prefixlen = ip_masklen (sl->mask);
	234	else
	235	p.prefixlen = IPV4_MAX_BITLEN;
	236
	237	apply_mask_ipv4 (&p);
	238
	239	if (sl->header.type == OSPF_SUMMARY_LSA &&
96735eea	240	(range = ospf_area_range_match_any (ospf, &p)) &&
718e3744	241	ospf_area_range_active (range))
	242	return 0;
	243
96735eea	244	if (ospf->abr_type != OSPF_ABR_STAND &&
96735eea	245	area->external_routing != OSPF_AREA_DEFAULT &&
718e3744	246	p.prefix.s_addr == OSPF_DEFAULT_DESTINATION &&
	247	p.prefixlen == 0)
	248	return 0; /* Ignore summary default from a stub area */
	249
	250	abr.family = AF_INET;
	251	abr.prefix = sl->header.adv_router;
	252	abr.prefixlen = IPV4_MAX_BITLEN;
	253	apply_mask_ipv4 (&abr);
	254
96735eea	255	abr_or = ospf_find_abr_route (rtrs, &abr, area);
718e3744	256
	257	if (abr_or == NULL)
	258	return 0;
	259
	260	new_or = ospf_route_new ();
	261	new_or->type = OSPF_DESTINATION_NETWORK;
	262	new_or->id = sl->header.id;
	263	new_or->mask = sl->mask;
	264	new_or->u.std.options = sl->header.options;
	265	new_or->u.std.origin = (struct lsa_header *) sl;
	266	new_or->cost = abr_or->cost + metric;
96735eea	267	new_or->u.std.area_id = area->area_id;
96735eea	268	new_or->u.std.external_routing = area->external_routing;
718e3744	269	new_or->path_type = OSPF_PATH_INTER_AREA;
	270
	271	if (sl->header.type == OSPF_SUMMARY_LSA)
96735eea	272	ospf_ia_network_route (ospf, rt, &p, new_or, abr_or);
718e3744	273	else
	274	{
	275	new_or->type = OSPF_DESTINATION_ROUTER;
	276	new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
96735eea	277	ospf_ia_router_route (ospf, rtrs, &p, new_or, abr_or);
718e3744	278	}
	279
	280	return 0;
	281	}
	282
	283	void
96735eea	284	ospf_examine_summaries (struct ospf_area *area,
718e3744	285	struct route_table *lsdb_rt,
	286	struct route_table *rt,
	287	struct route_table *rtrs)
	288	{
96735eea	289	struct ospf_lsa *lsa;
	290	struct route_node *rn;
	291
	292	LSDB_LOOP (lsdb_rt, rn, lsa)
	293	process_summary_lsa (area, rt, rtrs, lsa);
718e3744	294	}
	295
	296	int
	297	ospf_area_is_transit (struct ospf_area *area)
	298	{
	299	return (area->transit == OSPF_TRANSIT_TRUE) \|\|
	300	ospf_full_virtual_nbrs(area); /* Cisco forgets to set the V-bit :( */
	301	}
	302
	303	void
96735eea	304	ospf_update_network_route (struct ospf *ospf,
96735eea	305	struct route_table *rt,
718e3744	306	struct route_table *rtrs,
	307	struct summary_lsa *lsa,
	308	struct prefix_ipv4 *p,
	309	struct ospf_area *area)
	310	{
	311	struct route_node *rn;
	312	struct ospf_route or, abr_or, *new_or;
	313	struct prefix_ipv4 abr;
	314	u_int32_t cost;
	315
	316	abr.family = AF_INET;
	317	abr.prefix =lsa->header.adv_router;
	318	abr.prefixlen = IPV4_MAX_BITLEN;
	319	apply_mask_ipv4 (&abr);
	320
	321	abr_or = ospf_find_abr_route (rtrs, &abr, area);
	322
	323	if (abr_or == NULL)
	324	{
	325	if (IS_DEBUG_OSPF_EVENT)
	326	zlog_info ("ospf_update_network_route(): can't find a route to the ABR");
	327	return;
	328	}
	329
	330	cost = abr_or->cost + GET_METRIC (lsa->metric);
	331
	332	rn = route_node_lookup (rt, (struct prefix *) p);
	333
	334	if (! rn)
	335	{
96735eea	336	if (ospf->abr_type != OSPF_ABR_SHORTCUT)
718e3744	337	return; /* Standard ABR can update only already installed
	338	backbone paths */
	339	if (IS_DEBUG_OSPF_EVENT)
	340	zlog_info ("ospf_update_network_route(): "
	341	"Allowing Shortcut ABR to add new route");
	342	new_or = ospf_route_new ();
	343	new_or->type = OSPF_DESTINATION_NETWORK;
	344	new_or->id = lsa->header.id;
	345	new_or->mask = lsa->mask;
	346	new_or->u.std.options = lsa->header.options;
	347	new_or->u.std.origin = (struct lsa_header *) lsa;
	348	new_or->cost = cost;
	349	new_or->u.std.area_id = area->area_id;
718e3744	350	new_or->u.std.external_routing = area->external_routing;
718e3744	351	new_or->path_type = OSPF_PATH_INTER_AREA;
	352	ospf_route_add (rt, p, new_or, abr_or);
	353
	354	return;
	355	}
	356	else
	357	{
	358	route_unlock_node (rn);
	359	if (rn->info == NULL)
	360	return;
	361	}
	362
	363	or = rn->info;
	364
	365	if (or->path_type != OSPF_PATH_INTRA_AREA &&
	366	or->path_type != OSPF_PATH_INTER_AREA)
	367	{
	368	if (IS_DEBUG_OSPF_EVENT)
	369	zlog_info ("ospf_update_network_route(): ERR: path type is wrong");
	370	return;
	371	}
	372
96735eea	373	if (ospf->abr_type == OSPF_ABR_SHORTCUT)
718e3744	374	{
	375	if (or->path_type == OSPF_PATH_INTRA_AREA &&
	376	!OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
	377	{
	378	if (IS_DEBUG_OSPF_EVENT)
	379	zlog_info ("ospf_update_network_route(): Shortcut: "
	380	"this intra-area path is not backbone");
	381	return;
	382	}
	383	}
	384	else /* Not Shortcut ABR */
	385	{
	386	if (!OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
	387	{
	388	if (IS_DEBUG_OSPF_EVENT)
	389	zlog_info ("ospf_update_network_route(): "
	390	"route is not BB-associated");
	391	return; /* We can update only BB routes */
	392	}
	393	}
	394
	395	if (or->cost < cost)
	396	{
	397	if (IS_DEBUG_OSPF_EVENT)
	398	zlog_info ("ospf_update_network_route(): new route is worse");
	399	return;
	400	}
	401
	402	if (or->cost == cost)
	403	{
	404	if (IS_DEBUG_OSPF_EVENT)
	405	zlog_info ("ospf_update_network_route(): "
	406	"new route is same distance, adding nexthops");
96735eea	407	ospf_route_copy_nexthops (or, abr_or->paths);
718e3744	408	}
	409
	410	if (or->cost > cost)
	411	{
	412	if (IS_DEBUG_OSPF_EVENT)
	413	zlog_info ("ospf_update_network_route(): "
	414	"new route is better, overriding nexthops");
96735eea	415	ospf_route_subst_nexthops (or, abr_or->paths);
718e3744	416	or->cost = cost;
718e3744	417
96735eea	418	if ((ospf->abr_type == OSPF_ABR_SHORTCUT) &&
718e3744	419	!OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
	420	{
	421	or->path_type = OSPF_PATH_INTER_AREA;
	422	or->u.std.area_id = area->area_id;
718e3744	423	or->u.std.external_routing = area->external_routing;
718e3744	424	/* Note that we can do this only in Shortcut ABR mode,
	425	because standard ABR must leave the route type and area
	426	unchanged
	427	*/
	428	}
	429	}
	430	}
	431
	432	void
96735eea	433	ospf_update_router_route (struct ospf *ospf,
96735eea	434	struct route_table *rtrs,
718e3744	435	struct summary_lsa *lsa,
	436	struct prefix_ipv4 *p,
	437	struct ospf_area *area)
	438	{
	439	struct ospf_route or, abr_or, *new_or;
	440	struct prefix_ipv4 abr;
	441	u_int32_t cost;
	442
	443	abr.family = AF_INET;
	444	abr.prefix = lsa->header.adv_router;
	445	abr.prefixlen = IPV4_MAX_BITLEN;
	446	apply_mask_ipv4 (&abr);
	447
	448	abr_or = ospf_find_abr_route (rtrs, &abr, area);
	449
	450	if (abr_or == NULL)
	451	{
	452	if (IS_DEBUG_OSPF_EVENT)
	453	zlog_info ("ospf_update_router_route(): can't find a route to the ABR");
	454	return;
	455	}
	456
	457	cost = abr_or->cost + GET_METRIC (lsa->metric);
	458
	459	/* First try to find a backbone path,
	460	because standard ABR can update only BB-associated paths */
	461
96735eea	462	if ((ospf->backbone == NULL) &&
96735eea	463	(ospf->abr_type != OSPF_ABR_SHORTCUT))
718e3744	464
	465	/* no BB area, not Shortcut ABR, exiting */
	466	return;
	467
96735eea	468	or = ospf_find_asbr_route_through_area (rtrs, p, ospf->backbone);
718e3744	469
	470	if (or == NULL)
	471	{
96735eea	472	if (ospf->abr_type != OSPF_ABR_SHORTCUT)
718e3744	473
	474	/* route to ASBR through the BB not found
	475	the router is not Shortcut ABR, exiting */
	476
	477	return;
	478	else
	479	/* We're a Shortcut ABR*/
	480	{
	481	/* Let it either add a new router or update the route
	482	through the same (non-BB) area. */
	483
	484	new_or = ospf_route_new ();
	485	new_or->type = OSPF_DESTINATION_ROUTER;
	486	new_or->id = lsa->header.id;
	487	new_or->mask = lsa->mask;
	488	new_or->u.std.options = lsa->header.options;
	489	new_or->u.std.origin = (struct lsa_header *)lsa;
	490	new_or->cost = cost;
	491	new_or->u.std.area_id = area->area_id;
718e3744	492	new_or->u.std.external_routing = area->external_routing;
718e3744	493	new_or->path_type = OSPF_PATH_INTER_AREA;
718e3744	494	new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
96735eea	495	ospf_ia_router_route (ospf, rtrs, p, new_or, abr_or);
718e3744	496
	497	return;
	498	}
	499	}
	500
	501	/* At this point the "or" is always bb-associated */
	502
	503	if (!(or->u.std.flags & ROUTER_LSA_EXTERNAL))
	504	{
	505	if (IS_DEBUG_OSPF_EVENT)
	506	zlog_info ("ospf_upd_router_route(): the remote router is not an ASBR");
	507	return;
	508	}
	509
	510	if (or->path_type != OSPF_PATH_INTRA_AREA &&
	511	or->path_type != OSPF_PATH_INTER_AREA)
	512	return;
	513
	514	if (or->cost < cost)
	515	return;
	516
	517	else if (or->cost == cost)
96735eea	518	ospf_route_copy_nexthops (or, abr_or->paths);
718e3744	519
	520	else if (or->cost > cost)
	521	{
96735eea	522	ospf_route_subst_nexthops (or, abr_or->paths);
718e3744	523	or->cost = cost;
	524
	525	/* Even if the ABR runs in Shortcut mode, we can't change
	526	the path type and area, because the "or" is always bb-associated
	527	at this point and even Shortcut ABR can't change these attributes */
	528	}
	529	}
	530
	531	int
96735eea	532	process_transit_summary_lsa (struct ospf_area area, struct route_table rt,
96735eea	533	struct route_table rtrs, struct ospf_lsa lsa)
718e3744	534	{
96735eea	535	struct ospf *ospf = area->ospf;
718e3744	536	struct summary_lsa *sl;
	537	struct prefix_ipv4 p;
	538	u_int32_t metric;
718e3744	539
96735eea	540	if (lsa == NULL)
718e3744	541	return 0;
718e3744	542
96735eea	543	sl = (struct summary_lsa *) lsa->data;
718e3744	544
	545	if (IS_DEBUG_OSPF_EVENT)
	546	zlog_info ("process_transit_summaries(): LS ID: %s",
96735eea	547	inet_ntoa (lsa->data->id));
718e3744	548	metric = GET_METRIC (sl->metric);
	549
	550	if (metric == OSPF_LS_INFINITY)
	551	{
	552	if (IS_DEBUG_OSPF_EVENT)
	553	zlog_info ("process_transit_summaries(): metric is infinity, skip");
	554	return 0;
	555	}
	556
96735eea	557	if (IS_LSA_MAXAGE (lsa))
718e3744	558	{
	559	if (IS_DEBUG_OSPF_EVENT)
	560	zlog_info ("process_transit_summaries(): This LSA is too old");
	561	return 0;
	562	}
	563
96735eea	564	if (ospf_lsa_is_self_originated (area->ospf, lsa))
718e3744	565	{
	566	if (IS_DEBUG_OSPF_EVENT)
	567	zlog_info ("process_transit_summaries(): This LSA is mine, skip");
	568	return 0;
	569	}
	570
	571	p.family = AF_INET;
	572	p.prefix = sl->header.id;
	573
	574	if (sl->header.type == OSPF_SUMMARY_LSA)
	575	p.prefixlen = ip_masklen (sl->mask);
	576	else
	577	p.prefixlen = IPV4_MAX_BITLEN;
	578
	579	apply_mask_ipv4 (&p);
	580
	581	if (sl->header.type == OSPF_SUMMARY_LSA)
96735eea	582	ospf_update_network_route (ospf, rt, rtrs, sl, &p, area);
718e3744	583	else
96735eea	584	ospf_update_router_route (ospf, rtrs, sl, &p, area);
718e3744	585
	586	return 0;
	587	}
	588
	589	void
	590	ospf_examine_transit_summaries (struct ospf_area *area,
718e3744	591	struct route_table *lsdb_rt,
	592	struct route_table *rt,
	593	struct route_table *rtrs)
	594	{
96735eea	595	struct ospf_lsa *lsa;
96735eea	596	struct route_node *rn;
718e3744	597
96735eea	598	LSDB_LOOP (lsdb_rt, rn, lsa)
96735eea	599	process_transit_summary_lsa (area, rt, rtrs, lsa);
718e3744	600	}
	601
	602	void
96735eea	603	ospf_ia_routing (struct ospf *ospf,
96735eea	604	struct route_table *rt,
718e3744	605	struct route_table *rtrs)
	606	{
	607	struct ospf_area * area;
	608
	609	if (IS_DEBUG_OSPF_EVENT)
	610	zlog_info ("ospf_ia_routing():start");
	611
96735eea	612	if (IS_OSPF_ABR (ospf))
718e3744	613	{
	614	listnode node;
	615	struct ospf_area *area;
	616
96735eea	617	switch (ospf->abr_type)
718e3744	618	{
	619	case OSPF_ABR_STAND:
	620	if (IS_DEBUG_OSPF_EVENT)
	621	zlog_info ("ospf_ia_routing():Standard ABR");
	622
96735eea	623	if ((area = ospf->backbone))
718e3744	624	{
	625	listnode node;
	626
	627	if (IS_DEBUG_OSPF_EVENT)
	628	{
	629	zlog_info ("ospf_ia_routing():backbone area found");
	630	zlog_info ("ospf_ia_routing():examining summaries");
	631	}
	632
	633	OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
	634
96735eea	635	for (node = listhead (ospf->areas); node; nextnode (node))
718e3744	636	if ((area = getdata (node)) != NULL)
96735eea	637	if (area != ospf->backbone)
718e3744	638	if (ospf_area_is_transit (area))
	639	OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
	640	}
	641	else
	642	if (IS_DEBUG_OSPF_EVENT)
	643	zlog_info ("ospf_ia_routing():backbone area NOT found");
	644	break;
	645	case OSPF_ABR_IBM:
	646	case OSPF_ABR_CISCO:
	647	if (IS_DEBUG_OSPF_EVENT)
	648	zlog_info ("ospf_ia_routing():Alternative Cisco/IBM ABR");
96735eea	649	area = ospf->backbone; /* Find the BB */
718e3744	650
718e3744	651	/* If we have an active BB connection */
96735eea	652	if (area && ospf_act_bb_connection (ospf))
718e3744	653	{
	654	if (IS_DEBUG_OSPF_EVENT)
	655	{
	656	zlog_info ("ospf_ia_routing(): backbone area found");
	657	zlog_info ("ospf_ia_routing(): examining BB summaries");
	658	}
	659
	660	OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
	661
96735eea	662	for (node = listhead (ospf->areas); node; nextnode (node))
718e3744	663	if ((area = getdata (node)) != NULL)
96735eea	664	if (area != ospf->backbone)
718e3744	665	if (ospf_area_is_transit (area))
	666	OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
	667	}
	668	else
	669	{ /* No active BB connection--consider all areas */
	670	if (IS_DEBUG_OSPF_EVENT)
	671	zlog_info ("ospf_ia_routing(): "
	672	"Active BB connection not found");
96735eea	673	for (node = listhead (ospf->areas); node; nextnode (node))
718e3744	674	if ((area = getdata (node)) != NULL)
	675	OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
	676	}
	677	break;
	678	case OSPF_ABR_SHORTCUT:
	679	if (IS_DEBUG_OSPF_EVENT)
	680	zlog_info ("ospf_ia_routing():Alternative Shortcut");
96735eea	681	area = ospf->backbone; /* Find the BB */
718e3744	682
718e3744	683	/* If we have an active BB connection */
96735eea	684	if (area && ospf_act_bb_connection (ospf))
718e3744	685	{
	686	if (IS_DEBUG_OSPF_EVENT)
	687	{
	688	zlog_info ("ospf_ia_routing(): backbone area found");
	689	zlog_info ("ospf_ia_routing(): examining BB summaries");
	690	}
	691	OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
	692	}
	693
96735eea	694	for (node = listhead (ospf->areas); node; nextnode (node))
718e3744	695	if ((area = getdata (node)) != NULL)
96735eea	696	if (area != ospf->backbone)
718e3744	697	if (ospf_area_is_transit (area) \|\|
718e3744	698	((area->shortcut_configured != OSPF_SHORTCUT_DISABLE) &&
96735eea	699	((ospf->backbone == NULL) \|\|
718e3744	700	((area->shortcut_configured == OSPF_SHORTCUT_ENABLE) &&
	701	area->shortcut_capability))))
	702	OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
	703	break;
	704	default:
	705	break;
	706	}
	707	}
	708	else
	709	{
	710	listnode node;
	711
	712	if (IS_DEBUG_OSPF_EVENT)
	713	zlog_info ("ospf_ia_routing():not ABR, considering all areas");
	714
96735eea	715	for (node = listhead (ospf->areas); node; nextnode (node))
718e3744	716	if ((area = getdata (node)) != NULL)
	717	OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
	718	}
	719	}