[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 this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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"

static 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 ;
	struct listnode *node;

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

	route_unlock_node(rn);

	for (ALL_LIST_ELEMENTS_RO((struct list *)rn->info, node, or))
		if (IPV4_ADDR_SAME(& or->u.std.area_id, &area->area_id)
		    && (or->u.std.flags & ROUTER_LSA_BORDER))
			return or ;

	return NULL;
}

static 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_debug(
			"ospf_ia_network_route(): processing summary route to %pFX",
			p);

	/* 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_debug(
					"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_debug(
				"ospf_ia_network_route(): add new route to %pFX",
				p);
		ospf_route_add(rt, p, new_or, abr_or);
	}
}

static 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_debug("ospf_ia_router_route(): considering %pFX", p);

	/* 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_debug(
				"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_debug(
					"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_debug(
					"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_debug("ospf_ia_router_route(): adding the new route");

	listnode_add(rn->info, new_or);
}


static 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;
	uint32_t metric;

	if (lsa == NULL)
		return 0;

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

	if (IS_DEBUG_OSPF_EVENT)
		zlog_debug("process_summary_lsa(): LS ID: %pI4",
			   &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;

	/* XXX: This check seems dubious to me. If an ABR has already decided
	 * to consider summaries received in this area, then why would one wish
	 * to exclude default?
	 */
	if (IS_OSPF_ABR(ospf) && 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;
}

static 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 :( */
}

static 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;
	uint32_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_debug(
				"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_debug(
				"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_debug(
				"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_debug(
					"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_debug(
					"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_debug(
				"ospf_update_network_route(): new route is worse");
		return;
	}

	if (or->cost == cost) {
		if (IS_DEBUG_OSPF_EVENT)
			zlog_debug(
				"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_debug(
				"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
			*/
		}
	}
}

static 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;
	uint32_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_debug(
				"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))
		return; /* no BB area, not Shortcut ABR, exiting */

	/* find the backbone route, if possible */
	if ((ospf->backbone == NULL)
	    || !(or = ospf_find_asbr_route_through_area(rtrs, p,
							ospf->backbone))) {
		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_debug(
				"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 */
	}
}

static 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;
	uint32_t metric;

	if (lsa == NULL)
		return 0;

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

	if (IS_DEBUG_OSPF_EVENT)
		zlog_debug("process_transit_summaries(): LS ID: %pI4",
			   &lsa->data->id);
	metric = GET_METRIC(sl->metric);

	if (metric == OSPF_LS_INFINITY) {
		if (IS_DEBUG_OSPF_EVENT)
			zlog_debug(
				"process_transit_summaries(): metric is infinity, skip");
		return 0;
	}

	if (IS_LSA_MAXAGE(lsa)) {
		if (IS_DEBUG_OSPF_EVENT)
			zlog_debug(
				"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_debug(
				"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;
}

static 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 listnode *node;
	struct ospf_area *area;

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

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

			if ((area = ospf->backbone)) {
				if (IS_DEBUG_OSPF_EVENT) {
					zlog_debug(
						"ospf_ia_routing():backbone area found");
					zlog_debug(
						"ospf_ia_routing():examining summaries");
				}

				OSPF_EXAMINE_SUMMARIES_ALL(area, rt, rtrs);

				for (ALL_LIST_ELEMENTS_RO(ospf->areas, node,
							  area))
					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_debug(
					"ospf_ia_routing():backbone area NOT found");
			break;
		case OSPF_ABR_IBM:
		case OSPF_ABR_CISCO:
			if (IS_DEBUG_OSPF_EVENT)
				zlog_debug(
					"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_debug(
						"ospf_ia_routing(): backbone area found");
					zlog_debug(
						"ospf_ia_routing(): examining BB summaries");
				}

				OSPF_EXAMINE_SUMMARIES_ALL(area, rt, rtrs);

				for (ALL_LIST_ELEMENTS_RO(ospf->areas, node,
							  area))
					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_debug(
						"ospf_ia_routing(): Active BB connection not found");
				for (ALL_LIST_ELEMENTS_RO(ospf->areas, node,
							  area))
					OSPF_EXAMINE_SUMMARIES_ALL(area, rt,
								   rtrs);
			}
			break;
		case OSPF_ABR_SHORTCUT:
			if (IS_DEBUG_OSPF_EVENT)
				zlog_debug(
					"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_debug(
						"ospf_ia_routing(): backbone area found");
					zlog_debug(
						"ospf_ia_routing(): examining BB summaries");
				}
				OSPF_EXAMINE_SUMMARIES_ALL(area, rt, rtrs);
			}

			for (ALL_LIST_ELEMENTS_RO(ospf->areas, node, area))
				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 {
		if (IS_DEBUG_OSPF_EVENT)
			zlog_debug(
				"ospf_ia_routing():not ABR, considering all areas");

		for (ALL_LIST_ELEMENTS_RO(ospf->areas, node, area))
			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	*
896014f4 DL	17	* You should have received a copy of the GNU General Public License along
	18	* with this program; see the file COPYING; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
718e3744	20	*/
	21
	22
	23	#include <zebra.h>
	24
	25	#include "thread.h"
	26	#include "memory.h"
	27	#include "hash.h"
	28	#include "linklist.h"
	29	#include "prefix.h"
	30	#include "table.h"
	31	#include "log.h"
	32
	33	#include "ospfd/ospfd.h"
	34	#include "ospfd/ospf_interface.h"
	35	#include "ospfd/ospf_ism.h"
	36	#include "ospfd/ospf_asbr.h"
	37	#include "ospfd/ospf_lsa.h"
	38	#include "ospfd/ospf_lsdb.h"
	39	#include "ospfd/ospf_neighbor.h"
	40	#include "ospfd/ospf_nsm.h"
	41	#include "ospfd/ospf_spf.h"
	42	#include "ospfd/ospf_route.h"
	43	#include "ospfd/ospf_ase.h"
	44	#include "ospfd/ospf_abr.h"
	45	#include "ospfd/ospf_ia.h"
	46	#include "ospfd/ospf_dump.h"
	47
d62a17ae	48	static struct ospf_route ospf_find_abr_route(struct route_table rtrs,
	49	struct prefix_ipv4 *abr,
	50	struct ospf_area *area)
718e3744	51	{
d62a17ae	52	struct route_node *rn;
	53	struct ospf_route * or ;
	54	struct listnode *node;
718e3744	55
d62a17ae	56	if ((rn = route_node_lookup(rtrs, (struct prefix *)abr)) == NULL)
d62a17ae	57	return NULL;
718e3744	58
d62a17ae	59	route_unlock_node(rn);
718e3744	60
d62a17ae	61	for (ALL_LIST_ELEMENTS_RO((struct list *)rn->info, node, or))
	62	if (IPV4_ADDR_SAME(& or->u.std.area_id, &area->area_id)
	63	&& (or->u.std.flags & ROUTER_LSA_BORDER))
	64	return or ;
718e3744	65
d62a17ae	66	return NULL;
718e3744	67	}
718e3744	68
d62a17ae	69	static void ospf_ia_network_route(struct ospf ospf, struct route_table rt,
	70	struct prefix_ipv4 *p,
	71	struct ospf_route *new_or,
	72	struct ospf_route *abr_or)
718e3744	73	{
d62a17ae	74	struct route_node *rn1;
	75	struct ospf_route * or ;
	76
	77	if (IS_DEBUG_OSPF_EVENT)
	78	zlog_debug(
ae32e1c2 DS	79	"ospf_ia_network_route(): processing summary route to %pFX",
ae32e1c2 DS	80	p);
d62a17ae	81
	82	/* Find a route to the same dest */
	83	if ((rn1 = route_node_lookup(rt, (struct prefix *)p))) {
	84	int res;
	85
	86	route_unlock_node(rn1);
	87
	88	if ((or = rn1->info)) {
	89	if (IS_DEBUG_OSPF_EVENT)
	90	zlog_debug(
3efd0893	91	"ospf_ia_network_route(): Found a route to the same network");
d62a17ae	92	/* Check the existing route. */
	93	if ((res = ospf_route_cmp(ospf, new_or, or)) < 0) {
	94	/* New route is better, so replace old one. */
	95	ospf_route_subst(rn1, new_or, abr_or);
	96	} else if (res == 0) {
	97	/* New and old route are equal, so next hops can
	98	* be added. */
	99	route_lock_node(rn1);
	100	ospf_route_copy_nexthops(or, abr_or->paths);
	101	route_unlock_node(rn1);
	102
	103	/* new route can be deleted, because existing
	104	* route has been updated. */
	105	ospf_route_free(new_or);
	106	} else {
	107	/* New route is worse, so free it. */
	108	ospf_route_free(new_or);
	109	return;
	110	}
	111	} /* if (or)*/
	112	} /if (rn1)/
	113	else { /* no route */
	114	if (IS_DEBUG_OSPF_EVENT)
	115	zlog_debug(
ae32e1c2 DS	116	"ospf_ia_network_route(): add new route to %pFX",
ae32e1c2 DS	117	p);
d62a17ae	118	ospf_route_add(rt, p, new_or, abr_or);
d62a17ae	119	}
718e3744	120	}
718e3744	121
d62a17ae	122	static void ospf_ia_router_route(struct ospf ospf, struct route_table rtrs,
	123	struct prefix_ipv4 *p,
	124	struct ospf_route *new_or,
	125	struct ospf_route *abr_or)
718e3744	126	{
d62a17ae	127	struct ospf_route * or = NULL;
	128	struct route_node *rn;
	129	int ret;
	130
	131	if (IS_DEBUG_OSPF_EVENT)
ae32e1c2	132	zlog_debug("ospf_ia_router_route(): considering %pFX", p);
96b663a3	133
d62a17ae	134	/* Find a route to the same dest */
	135	rn = route_node_get(rtrs, (struct prefix *)p);
	136
	137	if (rn->info == NULL)
	138	/* This is a new route */
	139	rn->info = list_new();
	140	else {
	141	struct ospf_area *or_area;
	142	or_area = ospf_area_lookup_by_area_id(ospf,
	143	new_or->u.std.area_id);
	144	assert(or_area);
	145	/* This is an additional route */
	146	route_unlock_node(rn);
	147	or = ospf_find_asbr_route_through_area(rtrs, p, or_area);
718e3744	148	}
718e3744	149
d62a17ae	150	if (or) {
	151	if (IS_DEBUG_OSPF_EVENT)
	152	zlog_debug(
3efd0893	153	"ospf_ia_router_route(): a route to the same ABR through the same area exists");
d62a17ae	154	/* New route is better */
	155	if ((ret = ospf_route_cmp(ospf, new_or, or)) < 0) {
	156	listnode_delete(rn->info, or);
	157	ospf_route_free(or);
	158	/* proceed down */
	159	}
	160	/* Routes are the same */
	161	else if (ret == 0) {
	162	if (IS_DEBUG_OSPF_EVENT)
	163	zlog_debug(
	164	"ospf_ia_router_route(): merging the new route");
	165
	166	ospf_route_copy_nexthops(or, abr_or->paths);
	167	ospf_route_free(new_or);
	168	return;
	169	}
	170	/* New route is worse */
	171	else {
	172	if (IS_DEBUG_OSPF_EVENT)
	173	zlog_debug(
	174	"ospf_ia_router_route(): skipping the new route");
	175	ospf_route_free(new_or);
	176	return;
	177	}
718e3744	178	}
718e3744	179
d62a17ae	180	ospf_route_copy_nexthops(new_or, abr_or->paths);
718e3744	181
d62a17ae	182	if (IS_DEBUG_OSPF_EVENT)
d62a17ae	183	zlog_debug("ospf_ia_router_route(): adding the new route");
718e3744	184
d62a17ae	185	listnode_add(rn->info, new_or);
718e3744	186	}
718e3744	187
6b0655a2	188
d62a17ae	189	static int process_summary_lsa(struct ospf_area area, struct route_table rt,
d62a17ae	190	struct route_table rtrs, struct ospf_lsa lsa)
718e3744	191	{
d62a17ae	192	struct ospf *ospf = area->ospf;
	193	struct ospf_area_range *range;
	194	struct ospf_route abr_or, new_or;
	195	struct summary_lsa *sl;
	196	struct prefix_ipv4 p, abr;
d7c0a89a	197	uint32_t metric;
d62a17ae	198
	199	if (lsa == NULL)
	200	return 0;
	201
	202	sl = (struct summary_lsa *)lsa->data;
	203
	204	if (IS_DEBUG_OSPF_EVENT)
96b663a3 MS	205	zlog_debug("process_summary_lsa(): LS ID: %pI4",
96b663a3 MS	206	&sl->header.id);
d62a17ae	207
	208	metric = GET_METRIC(sl->metric);
	209
	210	if (metric == OSPF_LS_INFINITY)
	211	return 0;
	212
	213	if (IS_LSA_MAXAGE(lsa))
	214	return 0;
	215
	216	if (ospf_lsa_is_self_originated(area->ospf, lsa))
	217	return 0;
	218
	219	p.family = AF_INET;
	220	p.prefix = sl->header.id;
	221
	222	if (sl->header.type == OSPF_SUMMARY_LSA)
	223	p.prefixlen = ip_masklen(sl->mask);
	224	else
	225	p.prefixlen = IPV4_MAX_BITLEN;
	226
	227	apply_mask_ipv4(&p);
	228
	229	if (sl->header.type == OSPF_SUMMARY_LSA
	230	&& (range = ospf_area_range_match_any(ospf, &p))
	231	&& ospf_area_range_active(range))
	232	return 0;
	233
	234	/* XXX: This check seems dubious to me. If an ABR has already decided
	235	* to consider summaries received in this area, then why would one wish
	236	* to exclude default?
	237	*/
	238	if (IS_OSPF_ABR(ospf) && ospf->abr_type != OSPF_ABR_STAND
	239	&& area->external_routing != OSPF_AREA_DEFAULT
	240	&& p.prefix.s_addr == OSPF_DEFAULT_DESTINATION && p.prefixlen == 0)
	241	return 0; /* Ignore summary default from a stub area */
	242
	243	abr.family = AF_INET;
	244	abr.prefix = sl->header.adv_router;
	245	abr.prefixlen = IPV4_MAX_BITLEN;
	246	apply_mask_ipv4(&abr);
	247
	248	abr_or = ospf_find_abr_route(rtrs, &abr, area);
	249
	250	if (abr_or == NULL)
	251	return 0;
	252
	253	new_or = ospf_route_new();
	254	new_or->type = OSPF_DESTINATION_NETWORK;
	255	new_or->id = sl->header.id;
	256	new_or->mask = sl->mask;
	257	new_or->u.std.options = sl->header.options;
	258	new_or->u.std.origin = (struct lsa_header *)sl;
	259	new_or->cost = abr_or->cost + metric;
	260	new_or->u.std.area_id = area->area_id;
	261	new_or->u.std.external_routing = area->external_routing;
	262	new_or->path_type = OSPF_PATH_INTER_AREA;
	263
	264	if (sl->header.type == OSPF_SUMMARY_LSA)
	265	ospf_ia_network_route(ospf, rt, &p, new_or, abr_or);
	266	else {
	267	new_or->type = OSPF_DESTINATION_ROUTER;
	268	new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
	269	ospf_ia_router_route(ospf, rtrs, &p, new_or, abr_or);
	270	}
271
272	return 0;
718e3744	273	}
718e3744	274
d62a17ae	275	static void ospf_examine_summaries(struct ospf_area *area,
	276	struct route_table *lsdb_rt,
	277	struct route_table *rt,
	278	struct route_table *rtrs)
718e3744	279	{
d62a17ae	280	struct ospf_lsa *lsa;
d62a17ae	281	struct route_node *rn;
96735eea	282
996c9314	283	LSDB_LOOP (lsdb_rt, rn, lsa)
044506e7	284	process_summary_lsa(area, rt, rtrs, lsa);
718e3744	285	}
718e3744	286
d62a17ae	287	int ospf_area_is_transit(struct ospf_area *area)
718e3744	288	{
d62a17ae	289	return (area->transit == OSPF_TRANSIT_TRUE)
	290	\|\| ospf_full_virtual_nbrs(
	291	area); /* Cisco forgets to set the V-bit :( */
718e3744	292	}
718e3744	293
d62a17ae	294	static void ospf_update_network_route(struct ospf ospf, struct route_table rt,
	295	struct route_table *rtrs,
	296	struct summary_lsa *lsa,
	297	struct prefix_ipv4 *p,
	298	struct ospf_area *area)
718e3744	299	{
d62a17ae	300	struct route_node *rn;
	301	struct ospf_route * or, abr_or, new_or;
	302	struct prefix_ipv4 abr;
d7c0a89a	303	uint32_t cost;
d62a17ae	304
	305	abr.family = AF_INET;
	306	abr.prefix = lsa->header.adv_router;
	307	abr.prefixlen = IPV4_MAX_BITLEN;
	308	apply_mask_ipv4(&abr);
	309
	310	abr_or = ospf_find_abr_route(rtrs, &abr, area);
	311
	312	if (abr_or == NULL) {
	313	if (IS_DEBUG_OSPF_EVENT)
	314	zlog_debug(
	315	"ospf_update_network_route(): can't find a route to the ABR");
	316	return;
718e3744	317	}
d62a17ae	318
	319	cost = abr_or->cost + GET_METRIC(lsa->metric);
	320
	321	rn = route_node_lookup(rt, (struct prefix *)p);
	322
	323	if (!rn) {
	324	if (ospf->abr_type != OSPF_ABR_SHORTCUT)
	325	return; /* Standard ABR can update only already
	326	installed
	327	backbone paths */
	328	if (IS_DEBUG_OSPF_EVENT)
	329	zlog_debug(
3efd0893	330	"ospf_update_network_route(): Allowing Shortcut ABR to add new route");
d62a17ae	331	new_or = ospf_route_new();
	332	new_or->type = OSPF_DESTINATION_NETWORK;
	333	new_or->id = lsa->header.id;
	334	new_or->mask = lsa->mask;
	335	new_or->u.std.options = lsa->header.options;
	336	new_or->u.std.origin = (struct lsa_header *)lsa;
	337	new_or->cost = cost;
	338	new_or->u.std.area_id = area->area_id;
	339	new_or->u.std.external_routing = area->external_routing;
	340	new_or->path_type = OSPF_PATH_INTER_AREA;
	341	ospf_route_add(rt, p, new_or, abr_or);
	342
	343	return;
	344	} else {
	345	route_unlock_node(rn);
	346	if (rn->info == NULL)
	347	return;
718e3744	348	}
718e3744	349
d62a17ae	350	or = rn->info;
	351
	352	if (or->path_type != OSPF_PATH_INTRA_AREA &&
	353	or->path_type != OSPF_PATH_INTER_AREA) {
	354	if (IS_DEBUG_OSPF_EVENT)
	355	zlog_debug(
	356	"ospf_update_network_route(): ERR: path type is wrong");
	357	return;
	358	}
	359
	360	if (ospf->abr_type == OSPF_ABR_SHORTCUT) {
9d303b37 DL	361	if (
	362	or->path_type == OSPF_PATH_INTRA_AREA
	363	&& !OSPF_IS_AREA_ID_BACKBONE(
	364	or->u.std.area_id)) {
d62a17ae	365	if (IS_DEBUG_OSPF_EVENT)
d62a17ae	366	zlog_debug(
3efd0893	367	"ospf_update_network_route(): Shortcut: this intra-area path is not backbone");
d62a17ae	368	return;
	369	}
	370	} else /* Not Shortcut ABR */
718e3744	371	{
d62a17ae	372	if (!OSPF_IS_AREA_ID_BACKBONE(or->u.std.area_id)) {
	373	if (IS_DEBUG_OSPF_EVENT)
	374	zlog_debug(
3efd0893	375	"ospf_update_network_route(): route is not BB-associated");
d62a17ae	376	return; /* We can update only BB routes */
	377	}
	378	}
718e3744	379
d62a17ae	380	if (or->cost < cost) {
	381	if (IS_DEBUG_OSPF_EVENT)
	382	zlog_debug(
	383	"ospf_update_network_route(): new route is worse");
	384	return;
	385	}
718e3744	386
d62a17ae	387	if (or->cost == cost) {
	388	if (IS_DEBUG_OSPF_EVENT)
	389	zlog_debug(
3efd0893	390	"ospf_update_network_route(): new route is same distance, adding nexthops");
d62a17ae	391	ospf_route_copy_nexthops(or, abr_or->paths);
d62a17ae	392	}
718e3744	393
d62a17ae	394	if (or->cost > cost) {
	395	if (IS_DEBUG_OSPF_EVENT)
	396	zlog_debug(
3efd0893	397	"ospf_update_network_route(): new route is better, overriding nexthops");
d62a17ae	398	ospf_route_subst_nexthops(or, abr_or->paths);
	399	or->cost = cost;
	400
	401	if ((ospf->abr_type == OSPF_ABR_SHORTCUT)
	402	&& !OSPF_IS_AREA_ID_BACKBONE(or->u.std.area_id)) {
	403	or->path_type = OSPF_PATH_INTER_AREA;
	404	or->u.std.area_id = area->area_id;
	405	or->u.std.external_routing = area->external_routing;
	406	/* Note that we can do this only in Shortcut ABR mode,
	407	because standard ABR must leave the route type and
	408	area
	409	unchanged
	410	*/
	411	}
	412	}
718e3744	413	}
718e3744	414
d62a17ae	415	static void ospf_update_router_route(struct ospf *ospf,
	416	struct route_table *rtrs,
	417	struct summary_lsa *lsa,
	418	struct prefix_ipv4 *p,
	419	struct ospf_area *area)
718e3744	420	{
d62a17ae	421	struct ospf_route * or, abr_or, new_or;
d62a17ae	422	struct prefix_ipv4 abr;
d7c0a89a	423	uint32_t cost;
d62a17ae	424
	425	abr.family = AF_INET;
	426	abr.prefix = lsa->header.adv_router;
	427	abr.prefixlen = IPV4_MAX_BITLEN;
	428	apply_mask_ipv4(&abr);
	429
	430	abr_or = ospf_find_abr_route(rtrs, &abr, area);
	431
	432	if (abr_or == NULL) {
	433	if (IS_DEBUG_OSPF_EVENT)
	434	zlog_debug(
	435	"ospf_update_router_route(): can't find a route to the ABR");
	436	return;
	437	}
718e3744	438
d62a17ae	439	cost = abr_or->cost + GET_METRIC(lsa->metric);
718e3744	440
d62a17ae	441	/* First try to find a backbone path,
d62a17ae	442	because standard ABR can update only BB-associated paths */
718e3744	443
d62a17ae	444	if ((ospf->backbone == NULL) && (ospf->abr_type != OSPF_ABR_SHORTCUT))
d62a17ae	445	return; /* no BB area, not Shortcut ABR, exiting */
718e3744	446
d62a17ae	447	/* find the backbone route, if possible */
	448	if ((ospf->backbone == NULL)
	449	\|\| !(or = ospf_find_asbr_route_through_area(rtrs, p,
	450	ospf->backbone))) {
	451	if (ospf->abr_type != OSPF_ABR_SHORTCUT)
718e3744	452
d62a17ae	453	/* route to ASBR through the BB not found
d62a17ae	454	the router is not Shortcut ABR, exiting */
718e3744	455
d62a17ae	456	return;
	457	else
	458	/* We're a Shortcut ABR*/
718e3744	459	{
d62a17ae	460	/* Let it either add a new router or update the route
	461	through the same (non-BB) area. */
	462
	463	new_or = ospf_route_new();
	464	new_or->type = OSPF_DESTINATION_ROUTER;
	465	new_or->id = lsa->header.id;
	466	new_or->mask = lsa->mask;
	467	new_or->u.std.options = lsa->header.options;
	468	new_or->u.std.origin = (struct lsa_header *)lsa;
	469	new_or->cost = cost;
	470	new_or->u.std.area_id = area->area_id;
	471	new_or->u.std.external_routing = area->external_routing;
	472	new_or->path_type = OSPF_PATH_INTER_AREA;
	473	new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
	474	ospf_ia_router_route(ospf, rtrs, p, new_or, abr_or);
	475
	476	return;
718e3744	477	}
d62a17ae	478	}
718e3744	479
d62a17ae	480	/* At this point the "or" is always bb-associated */
	481
	482	if (!(or->u.std.flags & ROUTER_LSA_EXTERNAL)) {
	483	if (IS_DEBUG_OSPF_EVENT)
	484	zlog_debug(
	485	"ospf_upd_router_route(): the remote router is not an ASBR");
	486	return;
	487	}
	488
	489	if (or->path_type != OSPF_PATH_INTRA_AREA &&
	490	or->path_type != OSPF_PATH_INTER_AREA)
	491	return;
	492
	493	if (or->cost < cost)
	494	return;
	495
	496	else if (or->cost == cost)
	497	ospf_route_copy_nexthops(or, abr_or->paths);
	498
	499	else if (or->cost > cost) {
	500	ospf_route_subst_nexthops(or, abr_or->paths);
	501	or->cost = cost;
	502
	503	/* Even if the ABR runs in Shortcut mode, we can't change
	504	the path type and area, because the "or" is always
	505	bb-associated
	506	at this point and even Shortcut ABR can't change these
	507	attributes */
	508	}
	509	}
	510
	511	static int process_transit_summary_lsa(struct ospf_area *area,
	512	struct route_table *rt,
	513	struct route_table *rtrs,
	514	struct ospf_lsa *lsa)
	515	{
	516	struct ospf *ospf = area->ospf;
	517	struct summary_lsa *sl;
	518	struct prefix_ipv4 p;
d7c0a89a	519	uint32_t metric;
d62a17ae	520
	521	if (lsa == NULL)
	522	return 0;
	523
	524	sl = (struct summary_lsa *)lsa->data;
	525
	526	if (IS_DEBUG_OSPF_EVENT)
96b663a3 MS	527	zlog_debug("process_transit_summaries(): LS ID: %pI4",
96b663a3 MS	528	&lsa->data->id);
d62a17ae	529	metric = GET_METRIC(sl->metric);
	530
	531	if (metric == OSPF_LS_INFINITY) {
	532	if (IS_DEBUG_OSPF_EVENT)
	533	zlog_debug(
	534	"process_transit_summaries(): metric is infinity, skip");
	535	return 0;
	536	}
	537
	538	if (IS_LSA_MAXAGE(lsa)) {
	539	if (IS_DEBUG_OSPF_EVENT)
	540	zlog_debug(
	541	"process_transit_summaries(): This LSA is too old");
	542	return 0;
	543	}
	544
	545	if (ospf_lsa_is_self_originated(area->ospf, lsa)) {
	546	if (IS_DEBUG_OSPF_EVENT)
	547	zlog_debug(
	548	"process_transit_summaries(): This LSA is mine, skip");
	549	return 0;
	550	}
	551
	552	p.family = AF_INET;
	553	p.prefix = sl->header.id;
	554
	555	if (sl->header.type == OSPF_SUMMARY_LSA)
	556	p.prefixlen = ip_masklen(sl->mask);
	557	else
	558	p.prefixlen = IPV4_MAX_BITLEN;
	559
	560	apply_mask_ipv4(&p);
	561
	562	if (sl->header.type == OSPF_SUMMARY_LSA)
	563	ospf_update_network_route(ospf, rt, rtrs, sl, &p, area);
	564	else
	565	ospf_update_router_route(ospf, rtrs, sl, &p, area);
	566
	567	return 0;
	568	}
	569
	570	static void ospf_examine_transit_summaries(struct ospf_area *area,
	571	struct route_table *lsdb_rt,
	572	struct route_table *rt,
	573	struct route_table *rtrs)
	574	{
	575	struct ospf_lsa *lsa;
	576	struct route_node *rn;
	577
996c9314	578	LSDB_LOOP (lsdb_rt, rn, lsa)
044506e7	579	process_transit_summary_lsa(area, rt, rtrs, lsa);
d62a17ae	580	}
	581
	582	void ospf_ia_routing(struct ospf ospf, struct route_table rt,
	583	struct route_table *rtrs)
	584	{
f7813c7c	585	struct listnode *node;
d62a17ae	586	struct ospf_area *area;
	587
	588	if (IS_DEBUG_OSPF_EVENT)
	589	zlog_debug("ospf_ia_routing():start");
	590
	591	if (IS_OSPF_ABR(ospf)) {
d62a17ae	592	switch (ospf->abr_type) {
	593	case OSPF_ABR_STAND:
	594	if (IS_DEBUG_OSPF_EVENT)
	595	zlog_debug("ospf_ia_routing():Standard ABR");
	596
	597	if ((area = ospf->backbone)) {
d62a17ae	598	if (IS_DEBUG_OSPF_EVENT) {
	599	zlog_debug(
	600	"ospf_ia_routing():backbone area found");
	601	zlog_debug(
	602	"ospf_ia_routing():examining summaries");
	603	}
	604
	605	OSPF_EXAMINE_SUMMARIES_ALL(area, rt, rtrs);
	606
	607	for (ALL_LIST_ELEMENTS_RO(ospf->areas, node,
	608	area))
	609	if (area != ospf->backbone)
	610	if (ospf_area_is_transit(area))
	611	OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL(
	612	area, rt, rtrs);
	613	} else if (IS_DEBUG_OSPF_EVENT)
	614	zlog_debug(
	615	"ospf_ia_routing():backbone area NOT found");
	616	break;
	617	case OSPF_ABR_IBM:
	618	case OSPF_ABR_CISCO:
	619	if (IS_DEBUG_OSPF_EVENT)
	620	zlog_debug(
	621	"ospf_ia_routing():Alternative Cisco/IBM ABR");
	622	area = ospf->backbone; /* Find the BB */
	623
	624	/* If we have an active BB connection */
	625	if (area && ospf_act_bb_connection(ospf)) {
	626	if (IS_DEBUG_OSPF_EVENT) {
	627	zlog_debug(
	628	"ospf_ia_routing(): backbone area found");
	629	zlog_debug(
	630	"ospf_ia_routing(): examining BB summaries");
	631	}
	632
	633	OSPF_EXAMINE_SUMMARIES_ALL(area, rt, rtrs);
	634
	635	for (ALL_LIST_ELEMENTS_RO(ospf->areas, node,
	636	area))
	637	if (area != ospf->backbone)
	638	if (ospf_area_is_transit(area))
	639	OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL(
	640	area, rt, rtrs);
	641	} else { /* No active BB connection--consider all areas
9d303b37	642	*/
d62a17ae	643	if (IS_DEBUG_OSPF_EVENT)
d62a17ae	644	zlog_debug(
3efd0893	645	"ospf_ia_routing(): Active BB connection not found");
d62a17ae	646	for (ALL_LIST_ELEMENTS_RO(ospf->areas, node,
	647	area))
	648	OSPF_EXAMINE_SUMMARIES_ALL(area, rt,
	649	rtrs);
	650	}
	651	break;
	652	case OSPF_ABR_SHORTCUT:
	653	if (IS_DEBUG_OSPF_EVENT)
	654	zlog_debug(
	655	"ospf_ia_routing():Alternative Shortcut");
	656	area = ospf->backbone; /* Find the BB */
	657
	658	/* If we have an active BB connection */
	659	if (area && ospf_act_bb_connection(ospf)) {
	660	if (IS_DEBUG_OSPF_EVENT) {
	661	zlog_debug(
	662	"ospf_ia_routing(): backbone area found");
	663	zlog_debug(
	664	"ospf_ia_routing(): examining BB summaries");
	665	}
	666	OSPF_EXAMINE_SUMMARIES_ALL(area, rt, rtrs);
	667	}
	668
	669	for (ALL_LIST_ELEMENTS_RO(ospf->areas, node, area))
	670	if (area != ospf->backbone)
	671	if (ospf_area_is_transit(area)
	672	\|\| ((area->shortcut_configured
	673	!= OSPF_SHORTCUT_DISABLE)
	674	&& ((ospf->backbone == NULL)
	675	\|\| ((area->shortcut_configured
	676	== OSPF_SHORTCUT_ENABLE)
	677	&& area->shortcut_capability))))
	678	OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL(
	679	area, rt, rtrs);
	680	break;
	681	default:
	682	break;
718e3744	683	}
d62a17ae	684	} else {
d62a17ae	685	if (IS_DEBUG_OSPF_EVENT)
	686	zlog_debug(
	687	"ospf_ia_routing():not ABR, considering all areas");
	688
	689	for (ALL_LIST_ELEMENTS_RO(ospf->areas, node, area))
	690	OSPF_EXAMINE_SUMMARIES_ALL(area, rt, rtrs);
	691	}
718e3744	692	}