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Diffstat (limited to 'ospfd/ospf_ia.c')
| -rw-r--r-- | ospfd/ospf_ia.c | 726 |
1 files changed, 726 insertions, 0 deletions
diff --git a/ospfd/ospf_ia.c b/ospfd/ospf_ia.c new file mode 100644 index 000000000..32c8d86b4 --- /dev/null +++ b/ospfd/ospf_ia.c @@ -0,0 +1,726 @@ +/* + * 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 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 (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->path); + 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 route_table *rt, struct prefix_ipv4 *p, + struct ospf_route *new_or, struct ospf_route *abr_or) +{ + struct route_node *rn; + struct ospf_route *or = NULL; + 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 (rt,(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 (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 (rt, 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 (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->path); + 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->path); + + if (IS_DEBUG_OSPF_EVENT) + zlog_info ("ospf_ia_router_route(): adding the new route"); + + listnode_add (rn->info, new_or); +} + + +struct ia_args +{ + struct route_table *rt; + struct route_table *rtrs; + struct ospf_area *area; +}; + +int +process_summary_lsa (struct ospf_lsa *l, void *v, int i) +{ + 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; + struct ia_args *args; + + if (l == NULL) + return 0; + + args = (struct ia_args *) v; + sl = (struct summary_lsa *) l->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 (l)) + return 0; + + if (ospf_lsa_is_self_originated (l)) + 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_top, &p)) && + ospf_area_range_active (range)) + return 0; + + if (ospf_top->abr_type != OSPF_ABR_STAND && + args->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 (args->rtrs, &abr, args->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 = args->area->area_id; +#ifdef HAVE_NSSA + new_or->u.std.external_routing = args->area->external_routing; +#endif /* HAVE_NSSA */ + new_or->path_type = OSPF_PATH_INTER_AREA; + + if (sl->header.type == OSPF_SUMMARY_LSA) + ospf_ia_network_route (args->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 (args->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 ia_args args = {rt, rtrs, area}; + foreach_lsa (lsdb_rt, &args, 0, process_summary_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 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_top->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; +#ifdef HAVE_NSSA + new_or->u.std.external_routing = area->external_routing; +#endif /* HAVE_NSSA */ + 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_top->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->path); + } + + 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->path); + or->cost = cost; + + if ((ospf_top->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; +#ifdef HAVE_NSSA + or->u.std.external_routing = area->external_routing; +#endif /* HAVE_NSSA */ + /* 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 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_top->backbone == NULL) && + (ospf_top->abr_type != OSPF_ABR_SHORTCUT)) + + /* no BB area, not Shortcut ABR, exiting */ + return; + + or = ospf_find_asbr_route_through_area (rtrs, p, ospf_top->backbone); + + if (or == NULL) + { + if (ospf_top->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; +#ifdef HAVE_NSSA + new_or->u.std.external_routing = area->external_routing; +#endif /* HAVE_NSSA */ + new_or->path_type = OSPF_PATH_INTER_AREA; + new_or->u.std.flags = ROUTER_LSA_EXTERNAL; + ospf_ia_router_route (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->path); + + else if (or->cost > cost) + { + ospf_route_subst_nexthops (or, abr_or->path); + 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_lsa *l, void *v, int i) +{ + struct summary_lsa *sl; + struct prefix_ipv4 p; + u_int32_t metric; + struct ia_args *args; + + if (l == NULL) + return 0; + + args = (struct ia_args *) v; + sl = (struct summary_lsa *) l->data; + + if (IS_DEBUG_OSPF_EVENT) + zlog_info ("process_transit_summaries(): LS ID: %s", + inet_ntoa (l->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 (l)) + { + if (IS_DEBUG_OSPF_EVENT) + zlog_info ("process_transit_summaries(): This LSA is too old"); + return 0; + } + + if (ospf_lsa_is_self_originated (l)) + { + 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 (args->rt, args->rtrs, sl, &p, args->area); + else + ospf_update_router_route (args->rtrs, sl, &p, args->area); + + return 0; +} + +void +ospf_examine_transit_summaries (struct ospf_area *area, + /* struct ospf_lsdb *lsdb, */ + struct route_table *lsdb_rt, + struct route_table *rt, + struct route_table *rtrs) +{ + struct ia_args args = {rt, rtrs, area}; + + /* ospf_lsdb_iterator (lsdb, &args, 0, process_transit_summary_lsa); */ + foreach_lsa (lsdb_rt, &args, 0, process_transit_summary_lsa); +} + +void +ospf_ia_routing (struct route_table *rt, + struct route_table *rtrs) +{ + struct ospf_area * area; + + if (IS_DEBUG_OSPF_EVENT) + zlog_info ("ospf_ia_routing():start"); + + if (OSPF_IS_ABR) + { + listnode node; + struct ospf_area *area; + + switch (ospf_top->abr_type) + { + case OSPF_ABR_STAND: + if (IS_DEBUG_OSPF_EVENT) + zlog_info ("ospf_ia_routing():Standard ABR"); + + if ((area = ospf_top->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_top->areas); node; nextnode (node)) + if ((area = getdata (node)) != NULL) + if (area != ospf_top->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_top->backbone; /* Find the BB */ + + /* If we have an active BB connection */ + if (area && ospf_act_bb_connection ()) + { + 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_top->areas); node; nextnode (node)) + if ((area = getdata (node)) != NULL) + if (area != ospf_top->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_top->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_top->backbone; /* Find the BB */ + + /* If we have an active BB connection */ + if (area && ospf_act_bb_connection ()) + { + 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_top->areas); node; nextnode (node)) + if ((area = getdata (node)) != NULL) + if (area != ospf_top->backbone) + if (ospf_area_is_transit (area) || + ((area->shortcut_configured != OSPF_SHORTCUT_DISABLE) && + ((ospf_top->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_top->areas); node; nextnode (node)) + if ((area = getdata (node)) != NULL) + OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs); + } +} |