ospf6_interface.c

linux 路由软件 可支持RIP OSPF BGP等

/*
 * Copyright (C) 2003 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 <zebra.h>

#include "memory.h"
#include "if.h"
#include "log.h"
#include "command.h"
#include "thread.h"
#include "prefix.h"
#include "plist.h"

#include "ospf6_lsa.h"
#include "ospf6_lsdb.h"
#include "ospf6_network.h"
#include "ospf6_message.h"
#include "ospf6_route.h"
#include "ospf6_top.h"
#include "ospf6_area.h"
#include "ospf6_interface.h"
#include "ospf6_neighbor.h"
#include "ospf6_intra.h"
#include "ospf6_spf.h"
#include "ospf6d.h"

unsigned char conf_debug_ospf6_interface = 0;

char *ospf6_interface_state_str[] =
{
  "None",
  "Down",
  "Loopback",
  "Waiting",
  "PointToPoint",
  "DROther",
  "BDR",
  "DR",
  NULL
};

struct ospf6_interface *
ospf6_interface_lookup_by_ifindex (int ifindex)
{
  struct ospf6_interface *oi;
  struct interface *ifp;

  ifp = if_lookup_by_index (ifindex);
  if (ifp == NULL)
    return (struct ospf6_interface *) NULL;

  oi = (struct ospf6_interface *) ifp->info;
  return oi;
}

struct ospf6_interface *
ospf6_interface_lookup_by_name (char *ifname)
{
  struct ospf6_interface *oi;
  struct interface *ifp;

  ifp = if_lookup_by_name (ifname);
  if (ifp == NULL)
    return (struct ospf6_interface *) NULL;

  oi = (struct ospf6_interface *) ifp->info;
  return oi;
}

/* schedule routing table recalculation */
void
ospf6_interface_lsdb_hook (struct ospf6_lsa *lsa)
{
  switch (ntohs (lsa->header->type))
    {
      case OSPF6_LSTYPE_LINK:
        if (OSPF6_INTERFACE (lsa->lsdb->data)->state == OSPF6_INTERFACE_DR)
          OSPF6_INTRA_PREFIX_LSA_SCHEDULE_TRANSIT (OSPF6_INTERFACE (lsa->lsdb->data));
        ospf6_spf_schedule (OSPF6_INTERFACE (lsa->lsdb->data)->area);
        break;

      default:
        break;
    }
}

/* Create new ospf6 interface structure */
struct ospf6_interface *
ospf6_interface_create (struct interface *ifp)
{
  struct ospf6_interface *oi;
  int iobuflen;

  oi = (struct ospf6_interface *)
    XMALLOC (MTYPE_OSPF6_IF, sizeof (struct ospf6_interface));

  if (oi)
    memset (oi, 0, sizeof (struct ospf6_interface));
  else
    {
      zlog_err ("Can't malloc ospf6_interface for ifindex %d", ifp->ifindex);
      return (struct ospf6_interface *) NULL;
    }

  oi->area = (struct ospf6_area *) NULL;
  oi->neighbor_list = list_new ();
  oi->neighbor_list->cmp = ospf6_neighbor_cmp;
  oi->linklocal_addr = (struct in6_addr *) NULL;
  oi->instance_id = 0;
  oi->transdelay = 1;
  oi->priority = 1;

  oi->hello_interval = 10;
  oi->dead_interval = 40;
  oi->rxmt_interval = 5;
  oi->cost = 1;
  oi->state = OSPF6_INTERFACE_DOWN;
  oi->flag = 0;

  /* Try to adjust I/O buffer size with IfMtu */
  oi->ifmtu = ifp->mtu;
  iobuflen = ospf6_iobuf_size (ifp->mtu);
  if (oi->ifmtu > iobuflen)
    {
      if (IS_OSPF6_DEBUG_INTERFACE)
        zlog_info ("Interface %s: IfMtu is adjusted to I/O buffer size: %d.",
                   ifp->name, iobuflen);
      oi->ifmtu = iobuflen;
    }

  oi->lsupdate_list = ospf6_lsdb_create (oi);
  oi->lsack_list = ospf6_lsdb_create (oi);
  oi->lsdb = ospf6_lsdb_create (oi);
  oi->lsdb->hook_add = ospf6_interface_lsdb_hook;
  oi->lsdb->hook_remove = ospf6_interface_lsdb_hook;
  oi->lsdb_self = ospf6_lsdb_create (oi);

  oi->route_connected = ospf6_route_table_create ();

  /* link both */
  oi->interface = ifp;
  ifp->info = oi;

  return oi;
}

void
ospf6_interface_delete (struct ospf6_interface *oi)
{
  listnode n;
  struct ospf6_neighbor *on;

  for (n = listhead (oi->neighbor_list); n; nextnode (n))
    {
      on = (struct ospf6_neighbor *) getdata (n);
      ospf6_neighbor_delete (on);
    }
  list_delete (oi->neighbor_list);

  THREAD_OFF (oi->thread_send_hello);
  THREAD_OFF (oi->thread_send_lsupdate);
  THREAD_OFF (oi->thread_send_lsack);

  ospf6_lsdb_remove_all (oi->lsdb);
  ospf6_lsdb_remove_all (oi->lsupdate_list);
  ospf6_lsdb_remove_all (oi->lsack_list);

  ospf6_lsdb_delete (oi->lsdb);
  ospf6_lsdb_delete (oi->lsdb_self);

  ospf6_lsdb_delete (oi->lsupdate_list);
  ospf6_lsdb_delete (oi->lsack_list);

  ospf6_route_table_delete (oi->route_connected);

  /* cut link */
  oi->interface->info = NULL;

  /* plist_name */
  if (oi->plist_name)
    XFREE (MTYPE_PREFIX_LIST_STR, oi->plist_name);

  XFREE (MTYPE_OSPF6_IF, oi);
}

void
ospf6_interface_enable (struct ospf6_interface *oi)
{
  UNSET_FLAG (oi->flag, OSPF6_INTERFACE_DISABLE);

  oi->thread_send_hello =
    thread_add_event (master, ospf6_hello_send, oi, 0);
}

void
ospf6_interface_disable (struct ospf6_interface *oi)
{
  listnode i;
  struct ospf6_neighbor *on;

  SET_FLAG (oi->flag, OSPF6_INTERFACE_DISABLE);

  for (i = listhead (oi->neighbor_list); i; nextnode (i))
    {
      on = (struct ospf6_neighbor *) getdata (i);
      ospf6_neighbor_delete (on);
    }
  list_delete_all_node (oi->neighbor_list);

  ospf6_lsdb_remove_all (oi->lsdb);
  ospf6_lsdb_remove_all (oi->lsupdate_list);
  ospf6_lsdb_remove_all (oi->lsack_list);

  THREAD_OFF (oi->thread_send_hello);
  THREAD_OFF (oi->thread_send_lsupdate);
  THREAD_OFF (oi->thread_send_lsack);
}

static struct in6_addr *
ospf6_interface_get_linklocal_address (struct interface *ifp)
{
  listnode n;
  struct connected *c;
  struct in6_addr *l = (struct in6_addr *) NULL;

  /* for each connected address */
  for (n = listhead (ifp->connected); n; nextnode (n))
    {
      c = (struct connected *) getdata (n);

      /* if family not AF_INET6, ignore */
      if (c->address->family != AF_INET6)
        continue;

      /* linklocal scope check */
      if (IN6_IS_ADDR_LINKLOCAL (&c->address->u.prefix6))
        l = &c->address->u.prefix6;
    }
  return l;
}

void
ospf6_interface_if_add (struct interface *ifp)
{
  struct ospf6_interface *oi;
  int iobuflen;

  oi = (struct ospf6_interface *) ifp->info;
  if (oi == NULL)
    return;

  /* Try to adjust I/O buffer size with IfMtu */
  if (oi->ifmtu == 0)
    oi->ifmtu = ifp->mtu;
  iobuflen = ospf6_iobuf_size (ifp->mtu);
  if (oi->ifmtu > iobuflen)
    {
      if (IS_OSPF6_DEBUG_INTERFACE)
        zlog_info ("Interface %s: IfMtu is adjusted to I/O buffer size: %d.",
                   ifp->name, iobuflen);
      oi->ifmtu = iobuflen;
    }

  /* interface start */
  if (oi->area)
    thread_add_event (master, interface_up, oi, 0);
}

void
ospf6_interface_if_del (struct interface *ifp)
{
  struct ospf6_interface *oi;

  oi = (struct ospf6_interface *) ifp->info;
  if (oi == NULL)
    return;

  /* interface stop */
  if (oi->area)
    thread_execute (master, interface_down, oi, 0);

  listnode_delete (oi->area->if_list, oi);
  oi->area = (struct ospf6_area *) NULL;

  /* cut link */
  oi->interface = NULL;
  ifp->info = NULL;

  ospf6_interface_delete (oi);
}

void
ospf6_interface_state_update (struct interface *ifp)
{
  struct ospf6_interface *oi;

  oi = (struct ospf6_interface *) ifp->info;
  if (oi == NULL)
    return;
  if (oi->area == NULL)
    return;

  if (if_is_up (ifp))
    thread_add_event (master, interface_up, oi, 0);
  else
    thread_add_event (master, interface_down, oi, 0);

  return;
}

void
ospf6_interface_connected_route_update (struct interface *ifp)
{
  struct ospf6_interface *oi;
  struct ospf6_route *route;
  struct connected *c;
  listnode i;

  oi = (struct ospf6_interface *) ifp->info;
  if (oi == NULL)
    return;

  /* reset linklocal pointer */
  oi->linklocal_addr = ospf6_interface_get_linklocal_address (ifp);

  /* if area is null, do not make connected-route list */
  if (oi->area == NULL)
    return;

  /* update "route to advertise" interface route table */
  ospf6_route_remove_all (oi->route_connected);
  for (i = listhead (oi->interface->connected); i; nextnode (i))
    {
      c = (struct connected *) getdata (i);

      if (c->address->family != AF_INET6)
        continue;

      CONTINUE_IF_ADDRESS_LINKLOCAL (IS_OSPF6_DEBUG_INTERFACE, c->address);
      CONTINUE_IF_ADDRESS_UNSPECIFIED (IS_OSPF6_DEBUG_INTERFACE, c->address);
      CONTINUE_IF_ADDRESS_LOOPBACK (IS_OSPF6_DEBUG_INTERFACE, c->address);
      CONTINUE_IF_ADDRESS_V4COMPAT (IS_OSPF6_DEBUG_INTERFACE, c->address);
      CONTINUE_IF_ADDRESS_V4MAPPED (IS_OSPF6_DEBUG_INTERFACE, c->address);

      /* apply filter */
      if (oi->plist_name)
        {
          struct prefix_list *plist;
          enum prefix_list_type ret;
          char buf[128];

          prefix2str (c->address, buf, sizeof (buf));
          plist = prefix_list_lookup (AFI_IP6, oi->plist_name);
          ret = prefix_list_apply (plist, (void *) c->address);
          if (ret == PREFIX_DENY)
            {
              if (IS_OSPF6_DEBUG_INTERFACE)
                zlog_info ("%s on %s filtered by prefix-list %s ",
                           buf, oi->interface->name, oi->plist_name);
              continue;
            }
        }

      route = ospf6_route_create ();
      memcpy (&route->prefix, c->address, sizeof (struct prefix));
      apply_mask (&route->prefix);
      route->type = OSPF6_DEST_TYPE_NETWORK;
      route->path.area_id = oi->area->area_id;
      route->path.type = OSPF6_PATH_TYPE_INTRA;
      route->path.cost = oi->cost;
      route->nexthop[0].ifindex = oi->interface->ifindex;
      inet_pton (AF_INET6, "::1", &route->nexthop[0].address);
      ospf6_route_add (route, oi->route_connected);
    }

  /* create new Link-LSA */
  OSPF6_LINK_LSA_SCHEDULE (oi);
  OSPF6_INTRA_PREFIX_LSA_SCHEDULE_TRANSIT (oi);
  OSPF6_INTRA_PREFIX_LSA_SCHEDULE_STUB (oi->area);
}

static void
ospf6_interface_state_change (u_char next_state, struct ospf6_interface *oi)
{
  u_char prev_state;

  prev_state = oi->state;
  oi->state = next_state;

  if (prev_state == next_state)
    return;

  /* log */
  if (IS_OSPF6_DEBUG_INTERFACE)
    {
      zlog_info ("Interface state change %s: %s -> %s", oi->interface->name,
                 ospf6_interface_state_str[prev_state],
                 ospf6_interface_state_str[next_state]);
    }

  if ((prev_state == OSPF6_INTERFACE_DR ||
       prev_state == OSPF6_INTERFACE_BDR) &&
      (next_state != OSPF6_INTERFACE_DR &&
       next_state != OSPF6_INTERFACE_BDR))
    ospf6_leave_alldrouters (oi->interface->ifindex);
  if ((prev_state != OSPF6_INTERFACE_DR &&
       prev_state != OSPF6_INTERFACE_BDR) &&
      (next_state == OSPF6_INTERFACE_DR ||
       next_state == OSPF6_INTERFACE_BDR))
    ospf6_join_alldrouters (oi->interface->ifindex);

  OSPF6_ROUTER_LSA_SCHEDULE (oi->area);
  if (next_state == OSPF6_INTERFACE_DOWN)
    {
      OSPF6_NETWORK_LSA_EXECUTE (oi);
      OSPF6_INTRA_PREFIX_LSA_EXECUTE_TRANSIT (oi);
      OSPF6_INTRA_PREFIX_LSA_SCHEDULE_STUB (oi->area);
    }
  else if (prev_state == OSPF6_INTERFACE_DR ||
           next_state == OSPF6_INTERFACE_DR)
    {
      OSPF6_NETWORK_LSA_SCHEDULE (oi);
      OSPF6_INTRA_PREFIX_LSA_SCHEDULE_TRANSIT (oi);
      OSPF6_INTRA_PREFIX_LSA_SCHEDULE_STUB (oi->area);
    }
}


/* DR Election, RFC2328 section 9.4 */

#define IS_ELIGIBLE(n) \
  ((n)->state >= OSPF6_NEIGHBOR_TWOWAY && (n)->priority != 0)

static struct ospf6_neighbor *
better_bdrouter (struct ospf6_neighbor *a, struct ospf6_neighbor *b)
{
  if ((a == NULL || ! IS_ELIGIBLE (a) || a->drouter == a->router_id) &&
      (b == NULL || ! IS_ELIGIBLE (b) || b->drouter == b->router_id))
    return NULL;
  else if (a == NULL || ! IS_ELIGIBLE (a) || a->drouter == a->router_id)
    return b;
  else if (b == NULL || ! IS_ELIGIBLE (b) || b->drouter == b->router_id)
    return a;

  if (a->bdrouter == a->router_id && b->bdrouter != b->router_id)
    return a;
  if (a->bdrouter != a->router_id && b->bdrouter == b->router_id)
    return b;

  if (a->priority > b->priority)
    return a;
  if (a->priority < b->priority)
    return b;

  if (ntohl (a->router_id) > ntohl (b->router_id))
    return a;
  if (ntohl (a->router_id) < ntohl (b->router_id))
    return b;

  zlog_warn ("Router-ID duplicate ?");
  return a;
}

static struct ospf6_neighbor *
better_drouter (struct ospf6_neighbor *a, struct ospf6_neighbor *b)
{
  if ((a == NULL || ! IS_ELIGIBLE (a) || a->drouter != a->router_id) &&
      (b == NULL || ! IS_ELIGIBLE (b) || b->drouter != b->router_id))
    return NULL;
  else if (a == NULL || ! IS_ELIGIBLE (a) || a->drouter != a->router_id)
    return b;
  else if (b == NULL || ! IS_ELIGIBLE (b) || b->drouter != b->router_id)
    return a;

  if (a->drouter == a->router_id && b->drouter != b->router_id)
    return a;
  if (a->drouter != a->router_id && b->drouter == b->router_id)
    return b;

  if (a->priority > b->priority)
    return a;
  if (a->priority < b->priority)
    return b;

  if (ntohl (a->router_id) > ntohl (b->router_id))
    return a;
  if (ntohl (a->router_id) < ntohl (b->router_id))
    return b;

  zlog_warn ("Router-ID duplicate ?");
  return a;
}

static u_char
dr_election (struct ospf6_interface *oi)
{
  listnode i;
  struct ospf6_neighbor *on, *drouter, *bdrouter, myself;
  struct ospf6_neighbor *best_drouter, *best_bdrouter;
  u_char next_state = 0;

  drouter = bdrouter = NULL;
  best_drouter = best_bdrouter = NULL;

  /* pseudo neighbor myself, including noting current DR/BDR (1) */
  memset (&myself, 0, sizeof (myself));
  inet_ntop (AF_INET, &oi->area->ospf6->router_id, myself.name,
             sizeof (myself.name));
  myself.state = OSPF6_NEIGHBOR_TWOWAY;
  myself.drouter = oi->drouter;
  myself.bdrouter = oi->bdrouter;
  myself.priority = oi->priority;
  myself.router_id = oi->area->ospf6->router_id;

  /* Electing BDR (2) */
  for (i = listhead (oi->neighbor_list); i; nextnode (i))
    {
      on = (struct ospf6_neighbor *) getdata (i);
      bdrouter = better_bdrouter (bdrouter, on);
    }
  best_bdrouter = bdrouter;
  bdrouter = better_bdrouter (best_bdrouter, &myself);

  /* Electing DR (3) */
  for (i = listhead (oi->neighbor_list); i; nextnode (i))
    {
      on = (struct ospf6_neighbor *) getdata (i);