ospf6_abr.c

大名鼎鼎的路由器源码。程序分ZEBRA、OSPFRIP等3个包。程序框架采用一个路由协议一个进程的方式

/*
 * Copyright (C) 2001 Yasuhiro Ohara
 *
 * 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 "ospf6d.h"

#include "ospf6_dump.h"
#include "ospf6_abr.h"

static int abr_index;
#define IS_OSPF6_DUMP_ABR (ospf6_dump_is_on (abr_index))

#define ADD    0
#define CHANGE 1
#define REMOVE 2

/* Inter-Area-Prefix-LSA Calculation */

static struct ospf6_route_req *
ospf6_abr_entry_lookup (struct ospf6_route_req *abr_entry,
                        u_int32_t router_id, struct ospf6_area *area)
{
  struct prefix_ls abr_id;
  char router_string[32];

  inet_ntop (AF_INET, &router_id, router_string, sizeof (router_string));

  //zlog_info ("ABR:   Finding router %s in area %s", router_string, area->str);

  memset (&abr_id, 0, sizeof (abr_id));
  abr_id.family = AF_UNSPEC;
  abr_id.prefixlen = 64; /* xxx */
  abr_id.id.s_addr = htonl (0);
  abr_id.adv_router.s_addr = router_id;

  ospf6_route_lookup (abr_entry, (struct prefix *) &abr_id,
                      area->table_topology);

  if (ospf6_route_end (abr_entry))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR:   Router %s not found in area %s",
                   router_string, area->str);
      return NULL;
    }

  if (abr_entry->path.area_id != area->area_id)
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: ABR area id mismatch");
      return NULL;
    }

  if (! CHECK_FLAG (abr_entry->path.router_bits, OSPF6_ROUTER_LSA_BIT_B))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: ABR entry's B bit off");
      return NULL;
    }

  return abr_entry;
}

static int
ospf6_abr_prefix_lsa_to_route (struct ospf6_lsa *lsa,
                               struct ospf6_route_req *request)
{
  struct ospf6_inter_area_prefix_lsa *iep;
  struct ospf6_route_req abr_entry;

  if (lsa->header->type != htons (OSPF6_LSA_TYPE_INTER_PREFIX))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: LSA type mismatch");
      return -1;
    }

  if (IS_LSA_MAXAGE (lsa))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: LSA MaxAge");
      return -1;
    }

  if (! ospf6_abr_entry_lookup (&abr_entry, lsa->header->adv_router,
                                (struct ospf6_area *) lsa->scope))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: ABR check failed");
      return -1;
    }

  iep = OSPF6_LSA_HEADER_END (lsa->header);

  memset (request, 0, sizeof (struct ospf6_route_req));
  request->route.type = OSPF6_DEST_TYPE_NETWORK;
  request->route.prefix.family = AF_INET6;
  request->route.prefix.prefixlen = iep->prefix.prefix_length;
  ospf6_prefix_in6_addr (&iep->prefix, &request->route.prefix.u.prefix6);

  request->path.cost = abr_entry.path.cost +
                      (ntohl (iep->metric) & ntohl (0x000fffff));
  request->path.type = OSPF6_PATH_TYPE_INTER;
  request->path.origin.type = lsa->header->type;
  request->path.origin.id = lsa->header->id;
  request->path.origin.adv_router = lsa->header->adv_router;
  memcpy (&request->nexthop.address, &abr_entry.nexthop.address,
          sizeof (request->nexthop.address));
  request->nexthop.ifindex = abr_entry.nexthop.ifindex;

  return 0;
}

void
ospf6_abr_prefix_lsa_add (struct ospf6_lsa *lsa)
{
  struct ospf6_route_req request;
  int ret;

  if (IS_OSPF6_DUMP_ABR)
    zlog_info ("ABR: Calculate %s", lsa->str);

  ret = ospf6_abr_prefix_lsa_to_route (lsa, &request);
  if (ret < 0)
    return;

  if (IS_OSPF6_DUMP_ABR)
    zlog_info ("ABR: Inter Area Route add for %s", lsa->str);

  ospf6_route_add (&request, ospf6->route_table);
}

void
ospf6_abr_prefix_lsa_remove (struct ospf6_lsa *lsa)
{
  struct ospf6_inter_area_prefix_lsa *iep;
  struct prefix_ipv6 prefix6;
  struct ospf6_route_req request;

  iep = OSPF6_LSA_HEADER_END (lsa->header);

  prefix6.family = AF_INET6;
  prefix6.prefixlen = iep->prefix.prefix_length;
  ospf6_prefix_in6_addr (&iep->prefix, &prefix6.prefix);

  if (IS_OSPF6_DUMP_ABR)
    zlog_info ("ABR: Inter Area Route remove for %s", lsa->str);

  for (ospf6_route_lookup (&request, (struct prefix *) &prefix6,
                           ospf6->route_table);
       ! ospf6_route_end (&request);
       ospf6_route_next (&request))
   {
     if (memcmp (&prefix6, &request.route.prefix, sizeof (prefix6)))
       break;
     if (request.path.origin.type != htons (OSPF6_LSA_TYPE_INTER_PREFIX) ||
         request.path.origin.adv_router != lsa->header->adv_router ||
         request.path.origin.id != lsa->header->id)
       continue;

     ospf6_route_remove (&request, ospf6->route_table);
   }
}

static int
ospf6_abr_router_lsa_to_route (struct ospf6_lsa *lsa,
                               struct ospf6_route_req *request)
{
  struct ospf6_inter_area_router_lsa *ier;
  struct ospf6_route_req abr_entry;

  if (lsa->header->type != htons (OSPF6_LSA_TYPE_INTER_ROUTER))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: LSA type mismatch");
      return -1;
    }

  if (IS_LSA_MAXAGE (lsa))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: LSA MaxAge");
      return -1;
    }

  if (! ospf6_abr_entry_lookup (&abr_entry, lsa->header->adv_router,
                                (struct ospf6_area *) lsa->scope))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: Advertising router check failed");
      return -1;
    }

  ier = OSPF6_LSA_HEADER_END (lsa->header);

  memset (request, 0, sizeof (struct ospf6_route_req));
  request->route.type = OSPF6_DEST_TYPE_ROUTER;
  request->route.prefix.family = AF_UNSPEC;
  request->route.prefix.prefixlen = 64; /* XXX */
  ((struct prefix_ls *) &request->route.prefix)->adv_router.s_addr
    = ier->router_id;

  request->path.cost = abr_entry.path.cost +
                      (ntohl (ier->metric & htonl (0x000fffff)));
  request->path.type = OSPF6_PATH_TYPE_INTER;
  request->path.origin.type = lsa->header->type;
  request->path.origin.id = lsa->header->id;
  request->path.origin.adv_router = lsa->header->adv_router;
  SET_FLAG (request->path.router_bits, OSPF6_ROUTER_LSA_BIT_E);
  request->path.capability[0] = ier->options[0];
  request->path.capability[1] = ier->options[1];
  request->path.capability[2] = ier->options[2];

  memcpy (&request->nexthop.address, &abr_entry.nexthop.address,
          sizeof (request->nexthop.address));
  request->nexthop.ifindex = abr_entry.nexthop.ifindex;

  return 0;
}

void
ospf6_abr_router_lsa_add (struct ospf6_lsa *lsa)
{
  struct ospf6_route_req request;
  int ret;

  if (IS_OSPF6_DUMP_ABR)
    zlog_info ("ABR: Calculate %s", lsa->str);

  ret = ospf6_abr_router_lsa_to_route (lsa, &request);
  if (ret < 0)
    return;

  if (IS_OSPF6_DUMP_ABR)
    zlog_info ("ABR: Inter Area Router add for %s", lsa->str);

  ospf6_route_add (&request, ospf6->topology_table);
}

void
ospf6_abr_router_lsa_remove (struct ospf6_lsa *lsa)
{
  struct ospf6_inter_area_router_lsa *ier;
  struct prefix_ls prefix_ls;
  struct ospf6_route_req request;

  ier = OSPF6_LSA_HEADER_END (lsa->header);

  memset (&prefix_ls, 0, sizeof (prefix_ls));
  prefix_ls.family = AF_INET6;
  prefix_ls.prefixlen = 64; /* XXX */
  prefix_ls.adv_router.s_addr = ier->router_id;

  if (IS_OSPF6_DUMP_ABR)
    zlog_info ("ABR: Inter Area Route remove for %s", lsa->str);

  for (ospf6_route_lookup (&request, (struct prefix *) &prefix_ls,
                           ospf6->route_table);
       ! ospf6_route_end (&request);
       ospf6_route_next (&request))
   {
     if (memcmp (&prefix_ls, &request.route.prefix, sizeof (prefix_ls)))
       break;
     if (request.path.origin.type != htons (OSPF6_LSA_TYPE_INTER_ROUTER) ||
         request.path.origin.adv_router != lsa->header->adv_router ||
         request.path.origin.id != lsa->header->id)
       continue;

     ospf6_route_remove (&request, ospf6->route_table);
   }
}


void
ospf6_abr_abr_entry_add (struct ospf6_route_req *abr_entry)
{
  struct ospf6_lsdb_node node;
  struct prefix_ls *abr_id;
  struct ospf6_route_req request;
  struct ospf6_area *area;

  if (IS_OSPF6_DUMP_ABR)
    zlog_info ("ABR: New Area Border Router found");

  area = ospf6_area_lookup (abr_entry->path.area_id, ospf6);
  if (! area)
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: Can't find associated area");
      return;
    }

  abr_id = (struct prefix_ls *) &abr_entry->route.prefix;
  if (! ospf6_abr_entry_lookup (&request, abr_id->adv_router.s_addr, area))
    {
      if (IS_OSPF6_DUMP_ABR)
        zlog_info ("ABR: back check failed");
      return;
    }

  /* for each inter-prefix LSA this ABR originated */
  for (ospf6_lsdb_type_router (&node, htons (OSPF6_LSA_TYPE_INTER_PREFIX),
                               abr_id->adv_router.s_addr, area->lsdb);
       ! ospf6_lsdb_is_end (&node);
       ospf6_lsdb_next (&node))
    ospf6_abr_prefix_lsa_add (node.lsa);

  /* for each inter-router LSA this ABR originated */
  for (ospf6_lsdb_type_router (&node, htons (OSPF6_LSA_TYPE_INTER_ROUTER),
                               abr_id->adv_router.s_addr, area->lsdb);
       ! ospf6_lsdb_is_end (&node);