bgpd.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

peer_af_flag_reset (struct peer *peer, afi_t afi, safi_t safi)
{
  int i;
  struct bgp_filter *filter;
  char orf_name[BUFSIZ];

  filter = &peer->filter[afi][safi];

  /* Clear neighbor filter and route-map */
  for (i = FILTER_IN; i < FILTER_MAX; i++)
    {
      if (filter->dlist[i].name)
	{
	  free (filter->dlist[i].name);
	  filter->dlist[i].name = NULL;
	}
      if (filter->plist[i].name)
	{
	  free (filter->plist[i].name);
	  filter->plist[i].name = NULL; 
	}
      if (filter->aslist[i].name)
	{
	  free (filter->aslist[i].name);
	  filter->aslist[i].name = NULL;
	}
      if (filter->map[i].name)
	{
	  free (filter->map[i].name);
	  filter->map[i].name = NULL;
	}
    }

  /* Clear unsuppress map.  */
  if (filter->usmap.name)
    free (filter->usmap.name);
  filter->usmap.name = NULL;
  filter->usmap.map = NULL;

  /* Clear neighbor's all address family flags.  */
  peer->af_flags[afi][safi] = 0;

  /* Clear neighbor's all address family sflags. */
  peer->af_sflags[afi][safi] = 0;

  /* Clear neighbor's all address family capabilities. */
  peer->af_cap[afi][safi] = 0;

  /* Clear ORF info */
  peer->orf_plist[afi][safi] = NULL;
  sprintf (orf_name, "%s.%d.%d", peer->host, afi, safi);
  prefix_bgp_orf_remove_all (orf_name);

  /* Set default neighbor send-community.  */
  if (! bgp_option_check (BGP_OPT_CONFIG_CISCO))
    {
      SET_FLAG (peer->af_flags[afi][safi], PEER_FLAG_SEND_COMMUNITY);
      SET_FLAG (peer->af_flags[afi][safi], PEER_FLAG_SEND_EXT_COMMUNITY);
    }

  /* Clear neighbor default_originate_rmap */
  if (peer->default_rmap[afi][safi].name)
    free (peer->default_rmap[afi][safi].name);
  peer->default_rmap[afi][safi].name = NULL;
  peer->default_rmap[afi][safi].map = NULL;

  /* Clear neighbor maximum-prefix */
  peer->pmax[afi][safi] = 0;
  peer->pmax_threshold[afi][safi] = MAXIMUM_PREFIX_THRESHOLD_DEFAULT;
}

/* peer global config reset */
void
peer_global_config_reset (struct peer *peer)
{
  peer->weight = 0;
  peer->change_local_as = 0;
  peer->ttl = (peer_sort (peer) == BGP_PEER_IBGP ? 255 : 1);
  if (peer->update_source)
    {
      sockunion_free (peer->update_source);
      peer->update_source = NULL;
    }
  if (peer->update_if)
    {
      XFREE (MTYPE_PEER_UPDATE_SOURCE, peer->update_if);
      peer->update_if = NULL;
    }

  if (peer_sort (peer) == BGP_PEER_IBGP)
    peer->v_routeadv = BGP_DEFAULT_IBGP_ROUTEADV;
  else
    peer->v_routeadv = BGP_DEFAULT_EBGP_ROUTEADV;

  peer->flags = 0;
  peer->config = 0;
  peer->holdtime = 0;
  peer->keepalive = 0;
  peer->connect = 0;
  peer->v_connect = BGP_DEFAULT_CONNECT_RETRY;
}

/* Check peer's AS number and determin is this peer IBGP or EBGP */
int
peer_sort (struct peer *peer)
{
  struct bgp *bgp;

  bgp = peer->bgp;

  /* Peer-group */
  if (CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    {
      if (peer->as)
	return (bgp->as == peer->as ? BGP_PEER_IBGP : BGP_PEER_EBGP);
      else
	{
	  struct peer *peer1;
	  peer1 = listnode_head (peer->group->peer);
	  if (peer1)
	    return (peer1->local_as == peer1->as 
		    ? BGP_PEER_IBGP : BGP_PEER_EBGP);
	} 
      return BGP_PEER_INTERNAL;
    }

  /* Normal peer */
  if (bgp && CHECK_FLAG (bgp->config, BGP_CONFIG_CONFEDERATION))
    {
      if (peer->local_as == 0)
	return BGP_PEER_INTERNAL;

      if (peer->local_as == peer->as)
	{
	  if (peer->local_as == bgp->confed_id)
	    return BGP_PEER_EBGP;
	  else
	    return BGP_PEER_IBGP;
	}

      if (bgp_confederation_peers_check (bgp, peer->as))
	return BGP_PEER_CONFED;

      return BGP_PEER_EBGP;
    }
  else
    {
      return (peer->local_as == 0
	      ? BGP_PEER_INTERNAL : peer->local_as == peer->as
	      ? BGP_PEER_IBGP : BGP_PEER_EBGP);
    }
}

/* Allocate new peer object.  */
static struct peer *
peer_new ()
{
  afi_t afi;
  safi_t safi;
  struct peer *peer;
  struct servent *sp;

  /* Allocate new peer. */
  peer = XMALLOC (MTYPE_BGP_PEER, sizeof (struct peer));
  memset (peer, 0, sizeof (struct peer));

  /* Set default value. */
  peer->fd = -1;
  peer->v_start = BGP_INIT_START_TIMER;
  peer->v_connect = BGP_DEFAULT_CONNECT_RETRY;
  peer->v_asorig = BGP_DEFAULT_ASORIGINATE;
  peer->status = Idle;
  peer->ostatus = Idle;
  peer->version = BGP_VERSION_4;
  peer->weight = 0;

  /* Set default flags.  */
  for (afi = AFI_IP; afi < AFI_MAX; afi++)
    for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++)
      {
	if (! bgp_option_check (BGP_OPT_CONFIG_CISCO))
	  {
	    SET_FLAG (peer->af_flags[afi][safi], PEER_FLAG_SEND_COMMUNITY);
	    SET_FLAG (peer->af_flags[afi][safi], PEER_FLAG_SEND_EXT_COMMUNITY);
	  }
	peer->orf_plist[afi][safi] = NULL;
      }
  SET_FLAG (peer->sflags, PEER_STATUS_CAPABILITY_OPEN);

  /* Create buffers.  */
  peer->ibuf = stream_new (BGP_MAX_PACKET_SIZE);
  peer->obuf = stream_fifo_new ();
  peer->work = stream_new (BGP_MAX_PACKET_SIZE);

  bgp_sync_init (peer);

  /* Get service port number.  */
  sp = getservbyname ("bgp", "tcp");
  peer->port = (sp == NULL) ? BGP_PORT_DEFAULT : ntohs (sp->s_port);

  return peer;
}

/* Create new BGP peer.  */
struct peer *
peer_create (union sockunion *su, struct bgp *bgp, as_t local_as,
	     as_t remote_as, afi_t afi, safi_t safi)
{
  int active;
  struct peer *peer;
  char buf[SU_ADDRSTRLEN];

  peer = peer_new ();
  peer->bgp = bgp;
  peer->su = *su;
  peer->local_as = local_as;
  peer->as = remote_as;
  peer->local_id = bgp->router_id;
  peer->v_holdtime = bgp->default_holdtime;
  peer->v_keepalive = bgp->default_keepalive;
  if (peer_sort (peer) == BGP_PEER_IBGP)
    peer->v_routeadv = BGP_DEFAULT_IBGP_ROUTEADV;
  else
    peer->v_routeadv = BGP_DEFAULT_EBGP_ROUTEADV;
  listnode_add_sort (bgp->peer, peer);

  active = peer_active (peer);

  if (afi && safi)
    peer->afc[afi][safi] = 1;

  /* Last read time set */
  peer->readtime = time (NULL);

  /* Last reset time set */
  peer->resettime = time (NULL);

  /* Default TTL set. */
  peer->ttl = (peer_sort (peer) == BGP_PEER_IBGP ? 255 : 1);

  /* Make peer's address string. */
  sockunion2str (su, buf, SU_ADDRSTRLEN);
  peer->host = strdup (buf);

  /* Set up peer's events and timers. */
  if (! active && peer_active (peer))
    bgp_timer_set (peer);

  return peer;
}

/* Make accept BGP peer.  Called from bgp_accept (). */
struct peer *
peer_create_accept (struct bgp *bgp)
{
  struct peer *peer;

  peer = peer_new ();
  peer->bgp = bgp;
  listnode_add_sort (bgp->peer, peer);

  return peer;
}

/* Change peer's AS number.  */
void
peer_as_change (struct peer *peer, as_t as)
{
  int type;

  /* Stop peer. */
  if (! CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    {
      if (peer->status == Established)
	{
	  peer->last_reset = PEER_DOWN_REMOTE_AS_CHANGE;
	  bgp_notify_send (peer, BGP_NOTIFY_CEASE,
			   BGP_NOTIFY_CEASE_CONFIG_CHANGE);
	}
      else
	BGP_EVENT_ADD (peer, BGP_Stop);
    }
  type = peer_sort (peer);
  peer->as = as;

  if (bgp_config_check (peer->bgp, BGP_CONFIG_CONFEDERATION)
      && ! bgp_confederation_peers_check (peer->bgp, as)
      && peer->bgp->as != as)
    peer->local_as = peer->bgp->confed_id;
  else
    peer->local_as = peer->bgp->as;

  /* Advertisement-interval reset */
  if (peer_sort (peer) == BGP_PEER_IBGP)
    peer->v_routeadv = BGP_DEFAULT_IBGP_ROUTEADV;
  else
    peer->v_routeadv = BGP_DEFAULT_EBGP_ROUTEADV;

  /* TTL reset */
  if (peer_sort (peer) == BGP_PEER_IBGP)
    peer->ttl = 255;
  else if (type == BGP_PEER_IBGP)
    peer->ttl = 1;

  /* reflector-client reset */
  if (peer_sort (peer) != BGP_PEER_IBGP)
    {
      UNSET_FLAG (peer->af_flags[AFI_IP][SAFI_UNICAST],
		  PEER_FLAG_REFLECTOR_CLIENT);
      UNSET_FLAG (peer->af_flags[AFI_IP][SAFI_MULTICAST],
		  PEER_FLAG_REFLECTOR_CLIENT);
      UNSET_FLAG (peer->af_flags[AFI_IP][SAFI_MPLS_VPN],
		  PEER_FLAG_REFLECTOR_CLIENT);
      UNSET_FLAG (peer->af_flags[AFI_IP6][SAFI_UNICAST],
		  PEER_FLAG_REFLECTOR_CLIENT);
      UNSET_FLAG (peer->af_flags[AFI_IP6][SAFI_MULTICAST],
		  PEER_FLAG_REFLECTOR_CLIENT);
    }

  /* local-as reset */
  if (peer_sort (peer) != BGP_PEER_EBGP)
    {
      peer->change_local_as = 0;
      UNSET_FLAG (peer->flags, PEER_FLAG_LOCAL_AS_NO_PREPEND);
    }
}

/* If peer does not exist, create new one.  If peer already exists,
   set AS number to the peer.  */
int
peer_remote_as (struct bgp *bgp, union sockunion *su, as_t *as,
		afi_t afi, safi_t safi)
{
  struct peer *peer;
  as_t local_as;

  peer = peer_lookup (bgp, su);

  if (peer)
    {
      /* When this peer is a member of peer-group.  */
      if (peer->group)
	{
	  if (peer->group->conf->as)
	    {
	      /* Return peer group's AS number.  */
	      *as = peer->group->conf->as;
	      return BGP_ERR_PEER_GROUP_MEMBER;
	    }
	  if (peer_sort (peer->group->conf) == BGP_PEER_IBGP)
	    {
	      if (bgp->as != *as)
		{
		  *as = peer->as;
		  return BGP_ERR_PEER_GROUP_PEER_TYPE_DIFFERENT;
		}
	    }
	  else
	    {
	      if (bgp->as == *as)
		{
		  *as = peer->as;
		  return BGP_ERR_PEER_GROUP_PEER_TYPE_DIFFERENT;
		}
	    }
	}

      /* Existing peer's AS number change. */
      if (peer->as != *as)
	peer_as_change (peer, *as);
    }
  else
    {

      /* If the peer is not part of our confederation, and its not an
	 iBGP peer then spoof the source AS */
      if (bgp_config_check (bgp, BGP_CONFIG_CONFEDERATION)
	  && ! bgp_confederation_peers_check (bgp, *as) 
	  && bgp->as != *as)
	local_as = bgp->confed_id;
      else
	local_as = bgp->as;
      
      /* If this is IPv4 unicast configuration and "no bgp default
         ipv4-unicast" is specified. */

      if (bgp_flag_check (bgp, BGP_FLAG_NO_DEFAULT_IPV4)
	  && afi == AFI_IP && safi == SAFI_UNICAST)
	peer = peer_create (su, bgp, local_as, *as, 0, 0); 
      else
	peer = peer_create (su, bgp, local_as, *as, afi, safi); 
    }

  return 0;
}

/* Activate the peer or peer group for specified AFI and SAFI.  */
int
peer_activate (struct peer *peer, afi_t afi, safi_t safi)
{
  int active;

  if (peer->afc[afi][safi])
    return 0;

  /* Activate the address family configuration. */
  if (CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    peer->afc[afi][safi] = 1;
  else
    {
      active = peer_active (peer);

      peer->afc[afi][safi] = 1;

      if (! active && peer_active (peer))
	bgp_timer_set (peer);
      else
	{
	  if (peer->status == Established)
	    {
	      if (CHECK_FLAG (peer->cap, PEER_CAP_DYNAMIC_RCV))
		{
		  peer->afc_adv[afi][safi] = 1;
		  bgp_capability_send (peer, afi, safi,
				       CAPABILITY_CODE_MP,
				       CAPABILITY_ACTION_SET);
		  if (peer->afc_recv[afi][safi])
		    {
		      peer->afc_nego[afi][safi] = 1;
		      bgp_announce_route (peer, afi, safi);
		    }
		}
	      else
		{
		  peer->last_reset = PEER_DOWN_AF_ACTIVATE;
		  bgp_notify_send (peer, BGP_NOTIFY_CEASE,
			 	   BGP_NOTIFY_CEASE_CONFIG_CHANGE);
		}
	    }
	}
    }
  return 0;
}

int
peer_deactivate (struct peer *peer, afi_t afi, safi_t safi)
{
  struct peer_group *group;
  struct peer *peer1;
  struct listnode *nn;

  if (CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    {
      group = peer->group;

      LIST_LOOP (group->peer, peer1, nn)
	{
	  if (peer1->af_group[afi][safi])
	    return BGP_ERR_PEER_GROUP_MEMBER_EXISTS;
	}
    }
  else
    {
      if (peer->af_group[afi][safi])
	return BGP_ERR_PEER_BELONGS_TO_GROUP;
    }

  if (! peer->afc[afi][safi])
    return 0;

  /* De-activate the address family configuration. */
  peer->afc[afi][safi] = 0;
  peer_af_flag_reset (peer, afi, safi);

  if (! CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    {  
      if (peer->status == Established)
	{
	  if (CHECK_FLAG (peer->cap, PEER_CAP_DYNAMIC_RCV))
	    {
	      peer->afc_adv[afi][safi] = 0;
	      peer->afc_nego[afi][safi] = 0;

	      if (peer_active_nego (peer))
		{
		  bgp_capability_send (peer, afi, safi,
				       CAPABILITY_CODE_MP,
				       CAPABILITY_ACTION_UNSET);
		  bgp_clear_route (peer, afi, safi);
		  peer->pcount[afi][safi] = 0;
		}
	      else
		{
		  peer->last_reset = PEER_DOWN_NEIGHBOR_DELETE;
		  bgp_notify_send (peer, BGP_NOTIFY_CEASE,
				   BGP_NOTIFY_CEASE_CONFIG_CHANGE);
		}
	    }
	  else
	    {
	      peer->last_reset = PEER_DOWN_NEIGHBOR_DELETE;
	      bgp_notify_send (peer, BGP_NOTIFY_CEASE,
			       BGP_NOTIFY_CEASE_CONFIG_CHANGE);
	    }
	}
    }
  return 0;
}

/* Delete peer from confguration. */
int
peer_delete (struct peer *peer)
{
  int i;
  afi_t afi;
  safi_t safi;
  struct bgp *bgp;
  struct bgp_filter *filter;

  bgp = peer->bgp;

  /* If this peer belongs to peer group.  Clearn up the
     relationship.  */
  if (peer->group)
    {
      listnode_delete (peer->group->peer, peer);
      peer->group = NULL;
    }

  /* Withdraw all information from routing table.  We can not use
     BGP_EVENT_ADD (peer, BGP_Stop) at here.  Because the event is
     executed after peer structure is deleted. */
  peer->last_reset = PEER_DOWN_NEIGHBOR_DELETE;
  bgp_stop (peer);
  bgp_fsm_change_status (peer, Idle);

  /* Stop all timers. */
  BGP_TIMER_OFF (peer->t_start);
  BGP_TIMER_OFF (peer->t_connect);
  BGP_TIMER_OFF (peer->t_holdtime);
  BGP_TIMER_OFF (peer->t_keepalive);
  BGP_TIMER_OFF (peer->t_asorig);
  BGP_TIMER_OFF (peer->t_routeadv);

  /* Delete from all peer list. */
  if (! CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    listnode_delete (bgp->peer, peer);