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->last_reset = PEER_DOWN_RMAP_UNBIND;
      bgp_notify_send (peer, BGP_NOTIFY_CEASE,
		       BGP_NOTIFY_CEASE_CONFIG_CHANGE);
    }
  else
    BGP_EVENT_ADD (peer, BGP_Stop);

  return 0;
}

/* BGP instance creation by `router bgp' commands. */
struct bgp *
bgp_create (as_t *as, char *name)
{
  struct bgp *bgp;
  afi_t afi;
  safi_t safi;

  bgp = XCALLOC (MTYPE_BGP, sizeof (struct bgp));

  bgp->peer_self = peer_new ();
  bgp->peer_self->host = "Static announcement";

  bgp->peer = list_new ();
  bgp->peer->cmp = (int (*)(void *, void *)) peer_cmp;

  bgp->group = list_new ();
  bgp->group->cmp = (int (*)(void *, void *)) peer_group_cmp;

  for (afi = AFI_IP; afi < AFI_MAX; afi++)
    for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++)
      {
	bgp->route[afi][safi] = bgp_table_init ();
	bgp->aggregate[afi][safi] = bgp_table_init ();
	bgp->rib[afi][safi] = bgp_table_init ();
      }

  bgp->default_local_pref = BGP_DEFAULT_LOCAL_PREF;
  bgp->default_holdtime = BGP_DEFAULT_HOLDTIME;
  bgp->default_keepalive = BGP_DEFAULT_KEEPALIVE;

  bgp->as = *as;

  if (name)
    bgp->name = strdup (name);

  return bgp;
}

/* Return master of BGP. */
struct bgp_master *
bgp_get_master ()
{
  if (bm)
    return bm;
  return NULL;
}

/* Return first entry of BGP. */
struct bgp *
bgp_get_default ()
{
  if (bm->bgp->head)
    return bm->bgp->head->data;
  return NULL;
}

/* Lookup BGP entry. */
struct bgp *
bgp_lookup (as_t as, char *name)
{
  struct bgp *bgp;
  struct listnode *nn;

  LIST_LOOP (bm->bgp, bgp, nn)
    if (bgp->as == as
	&& ((bgp->name == NULL && name == NULL) 
	    || (bgp->name && name && strcmp (bgp->name, name) == 0)))
      return bgp;
  return NULL;
}

/* Lookup BGP structure by view name. */
struct bgp *
bgp_lookup_by_name (char *name)
{
  struct bgp *bgp;
  struct listnode *nn;

  LIST_LOOP (bm->bgp, bgp, nn)
    if ((bgp->name == NULL && name == NULL)
	|| (bgp->name && name && strcmp (bgp->name, name) == 0))
      return bgp;
  return NULL;
}

/* Called from VTY commands. */
int
bgp_get (struct bgp **bgp_val, as_t *as, char *name)
{
  struct bgp *bgp;

  /* Multiple instance check. */
  if (bgp_option_check (BGP_OPT_MULTIPLE_INSTANCE))
    {
      if (name)
	bgp = bgp_lookup_by_name (name);
      else
	bgp = bgp_get_default ();

      /* Already exists. */
      if (bgp)
	{
          if (bgp->as != *as)
	    {
	      *as = bgp->as;
	      return BGP_ERR_INSTANCE_MISMATCH;
	    }
	  *bgp_val = bgp;
	  return 0;
	}
    }
  else
    {
      /* BGP instance name can not be specified for single instance.  */
      if (name)
	return BGP_ERR_MULTIPLE_INSTANCE_NOT_SET;

      /* Get default BGP structure if exists. */
      bgp = bgp_get_default ();

      if (bgp)
	{
	  if (bgp->as != *as)
	    {
	      *as = bgp->as;
	      return BGP_ERR_AS_MISMATCH;
	    }
	  *bgp_val = bgp;
	  return 0;
	}
    }

  bgp = bgp_create (as, name);
  listnode_add (bm->bgp, bgp);
  bgp_if_update_all ();
  *bgp_val = bgp;

  return 0;
}

/* Delete BGP instance. */
int
bgp_delete (struct bgp *bgp)
{
  struct peer *peer;
  struct listnode *nn;
  struct listnode *next;
  afi_t afi;
  safi_t safi;
  int i;

  /* Delete static route. */
  bgp_static_delete (bgp);

  /* Unset redistribution. */
  for (afi = AFI_IP; afi < AFI_MAX; afi++)
    for (i = 0; i < ZEBRA_ROUTE_MAX; i++) 
      if (i != ZEBRA_ROUTE_BGP)
	bgp_redistribute_unset (bgp, afi, i);

  bgp->group->del = (void (*)(void *)) peer_group_delete;
  list_delete (bgp->group);

  for (nn = bgp->peer->head; nn; nn = next)
    {
      peer = nn->data;
      next = nn->next;
      peer_delete (peer);
    }

  listnode_delete (bm->bgp, bgp);

  if (bgp->name)
    free (bgp->name);
  
  for (afi = AFI_IP; afi < AFI_MAX; afi++)
    for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++)
      {
	if (bgp->route[afi][safi])
	  XFREE (MTYPE_ROUTE_TABLE, bgp->route[afi][safi]);
	if (bgp->aggregate[afi][safi])
	  XFREE (MTYPE_ROUTE_TABLE,bgp->aggregate[afi][safi]) ;
	if (bgp->rib[afi][safi])
	  XFREE (MTYPE_ROUTE_TABLE,bgp->rib[afi][safi]);
      }
  XFREE (MTYPE_BGP, bgp);

  return 0;
}

struct peer *
peer_lookup (struct bgp *bgp, union sockunion *su)
{
  struct peer *peer;
  struct listnode *nn;

  if (! bgp)
    bgp = bgp_get_default ();

  if (! bgp)
    return NULL;
  
  LIST_LOOP (bgp->peer, peer, nn)
    {
      if (sockunion_same (&peer->su, su)
	  && ! CHECK_FLAG (peer->sflags, PEER_STATUS_ACCEPT_PEER))
	return peer;
    }
  return NULL;
}

struct peer *
peer_lookup_with_open (union sockunion *su, as_t remote_as,
		       struct in_addr *remote_id, int *as)
{
  struct peer *peer;
  struct listnode *nn;
  struct bgp *bgp;

  bgp = bgp_get_default ();
  if (! bgp)
    return NULL;

  LIST_LOOP (bgp->peer, peer, nn)
    {
      if (sockunion_same (&peer->su, su)
	  && ! CHECK_FLAG (peer->sflags, PEER_STATUS_ACCEPT_PEER))
	{
	  if (peer->as == remote_as
	      && peer->remote_id.s_addr == remote_id->s_addr)
	    return peer;
	  if (peer->as == remote_as)
	    *as = 1;
	}
    }
  LIST_LOOP (bgp->peer, peer, nn)
    {
      if (sockunion_same (&peer->su, su)
	  &&  ! CHECK_FLAG (peer->sflags, PEER_STATUS_ACCEPT_PEER))
	{
	  if (peer->as == remote_as
	      && peer->remote_id.s_addr == 0)
	    return peer;
	  if (peer->as == remote_as)
	    *as = 1;
	}
    }
  return NULL;
}

/* If peer is configured at least one address family return 1. */
int
peer_active (struct peer *peer)
{
  if (peer->afc[AFI_IP][SAFI_UNICAST]
      || peer->afc[AFI_IP][SAFI_MULTICAST]
      || peer->afc[AFI_IP][SAFI_MPLS_VPN]
      || peer->afc[AFI_IP6][SAFI_UNICAST]
      || peer->afc[AFI_IP6][SAFI_MULTICAST])
    return 1;
  return 0;
}

/* If peer is negotiated at least one address family return 1. */
int
peer_active_nego (struct peer *peer)
{
  if (peer->afc_nego[AFI_IP][SAFI_UNICAST]
      || peer->afc_nego[AFI_IP][SAFI_MULTICAST]
      || peer->afc_nego[AFI_IP][SAFI_MPLS_VPN]
      || peer->afc_nego[AFI_IP6][SAFI_UNICAST]
      || peer->afc_nego[AFI_IP6][SAFI_MULTICAST])
    return 1;
  return 0;
}

/* peer_flag_change_type. */
enum peer_change_type
{
  peer_change_none,
  peer_change_reset,
  peer_change_reset_in,
  peer_change_reset_out,
};

void
peer_change_action (struct peer *peer, afi_t afi, safi_t safi,
		    enum peer_change_type type)
{
  if (CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    return;

  if (type == peer_change_reset)
    bgp_notify_send (peer, BGP_NOTIFY_CEASE,
		     BGP_NOTIFY_CEASE_CONFIG_CHANGE);
  else if (type == peer_change_reset_in)
    {
      if (CHECK_FLAG (peer->cap, PEER_CAP_REFRESH_OLD_RCV)
	  || CHECK_FLAG (peer->cap, PEER_CAP_REFRESH_NEW_RCV))
	bgp_route_refresh_send (peer, afi, safi, 0, 0, 0);
      else
	bgp_notify_send (peer, BGP_NOTIFY_CEASE,
			 BGP_NOTIFY_CEASE_CONFIG_CHANGE);
    }
  else if (type == peer_change_reset_out)
    bgp_announce_route (peer, afi, safi);
}

struct peer_flag_action
{
  /* Peer's flag.  */
  u_int32_t flag;

  /* This flag can be set for peer-group member.  */
  u_char not_for_member;

  /* Action when the flag is changed.  */
  enum peer_change_type type;

  /* Peer down cause */
  u_char peer_down;
};

struct peer_flag_action peer_flag_action_list[] = 
  {
    { PEER_FLAG_PASSIVE,                  0, peer_change_reset },
    { PEER_FLAG_SHUTDOWN,                 0, peer_change_reset },
    { PEER_FLAG_DONT_CAPABILITY,          0, peer_change_none },
    { PEER_FLAG_OVERRIDE_CAPABILITY,      0, peer_change_none },
    { PEER_FLAG_STRICT_CAP_MATCH,         0, peer_change_none },
    { PEER_FLAG_NO_ROUTE_REFRESH_CAP,     0, peer_change_reset },
    { PEER_FLAG_DYNAMIC_CAPABILITY,       0, peer_change_reset },
    { PEER_FLAG_ENFORCE_MULTIHOP,         0, peer_change_reset },
    { 0, 0, 0 }
  };

struct peer_flag_action peer_af_flag_action_list[] = 
  {
    { PEER_FLAG_NEXTHOP_SELF,             1, peer_change_reset_out },
    { PEER_FLAG_SEND_COMMUNITY,           1, peer_change_reset_out },
    { PEER_FLAG_SEND_EXT_COMMUNITY,       1, peer_change_reset_out },
    { PEER_FLAG_SOFT_RECONFIG,            0, peer_change_reset_in },
    { PEER_FLAG_REFLECTOR_CLIENT,         1, peer_change_reset },
    { PEER_FLAG_RSERVER_CLIENT,           1, peer_change_reset },
    { PEER_FLAG_AS_PATH_UNCHANGED,        1, peer_change_reset_out },
    { PEER_FLAG_NEXTHOP_UNCHANGED,        1, peer_change_reset_out },
    { PEER_FLAG_MED_UNCHANGED,            1, peer_change_reset_out },
    { PEER_FLAG_REMOVE_PRIVATE_AS,        1, peer_change_reset_out },
    { PEER_FLAG_ALLOWAS_IN,               0, peer_change_reset_in },
    { PEER_FLAG_ORF_PREFIX_SM,            1, peer_change_reset },
    { PEER_FLAG_ORF_PREFIX_RM,            1, peer_change_reset },
    { 0, 0, 0 }
  };

/* Proper action set. */
int
peer_flag_action_set (struct peer_flag_action *action_list, int size,
		      struct peer_flag_action *action, u_int32_t flag)
{
  int i;
  int found = 0;
  int reset_in = 0;
  int reset_out = 0;
  struct peer_flag_action *match = NULL;

  /* Check peer's frag action.  */
  for (i = 0; i < size; i++)
    {
      match = &action_list[i];

      if (match->flag == 0)
	break;

      if (match->flag & flag)
	{
	  found = 1;

	  if (match->type == peer_change_reset_in)
	    reset_in = 1;
	  if (match->type == peer_change_reset_out)
	    reset_out = 1;
	  if (match->type == peer_change_reset)
	    {
	      reset_in = 1;
	      reset_out = 1;
	    }
	  if (match->not_for_member)
	    action->not_for_member = 1;
	}
    }

  /* Set peer clear type.  */
  if (reset_in && reset_out)
    action->type = peer_change_reset;
  else if (reset_in)
    action->type = peer_change_reset_in;
  else if (reset_out)
    action->type = peer_change_reset_out;
  else
    action->type = peer_change_none;

  return found;
}

void
peer_flag_modify_action (struct peer *peer, u_int32_t flag)
{
  if (flag == PEER_FLAG_SHUTDOWN)
    {
      if (CHECK_FLAG (peer->flags, flag))
	{
	  if (peer->status == Established)
	    bgp_notify_send (peer, BGP_NOTIFY_CEASE,
			     BGP_NOTIFY_CEASE_ADMIN_SHUTDOWN);
	  else
	    BGP_EVENT_ADD (peer, BGP_Stop);
	}
      else
	{
	  peer->v_start = BGP_INIT_START_TIMER;
	  BGP_EVENT_ADD (peer, BGP_Stop);
	}
    }
  else if (peer->status == Established)
    {
      if (flag == PEER_FLAG_NO_ROUTE_REFRESH_CAP
	  && CHECK_FLAG (peer->cap, PEER_CAP_DYNAMIC_RCV))
	{
	  if (CHECK_FLAG (peer->flags, flag))
	    UNSET_FLAG (peer->cap, PEER_CAP_REFRESH_ADV);
	  else
	    SET_FLAG (peer->cap, PEER_CAP_REFRESH_ADV);

	  bgp_capability_send (peer, AFI_IP, SAFI_UNICAST,
			       CAPABILITY_CODE_REFRESH,
			       CHECK_FLAG (peer->flags, flag) ?
			       CAPABILITY_ACTION_UNSET : CAPABILITY_ACTION_SET);
	}
      else
	{
	  if (flag == PEER_FLAG_NO_ROUTE_REFRESH_CAP)
	    peer->last_reset = PEER_DOWN_CAPABILITY_CHANGE;
	  else if (flag == PEER_FLAG_DYNAMIC_CAPABILITY)
	    peer->last_reset = PEER_DOWN_CAPABILITY_CHANGE;
	  else if (flag == PEER_FLAG_PASSIVE)
	    peer->last_reset = PEER_DOWN_PASSIVE_CHANGE;
	  else if (flag == PEER_FLAG_ENFORCE_MULTIHOP)
	    peer->last_reset = PEER_DOWN_MULTIHOP_CHANGE;

	  bgp_notify_send (peer, BGP_NOTIFY_CEASE,
			   BGP_NOTIFY_CEASE_CONFIG_CHANGE);
	}
    }
  else
    BGP_EVENT_ADD (peer, BGP_Stop);
}

/* Change specified peer flag. */
int
peer_flag_modify (struct peer *peer, u_int32_t flag, int set)
{
  int found;
  int size;
  struct peer_group *group;
  struct listnode *nn;
  struct peer_flag_action action;

  memset (&action, 0, sizeof (struct peer_flag_action));
  size = sizeof peer_flag_action_list / sizeof (struct peer_flag_action);

  found = peer_flag_action_set (peer_flag_action_list, size, &action, flag);

  /* No flag action is found.  */
  if (! found)
    return BGP_ERR_INVALID_FLAG;    

  /* Not for peer-group member.  */
  if (action.not_for_member && peer_group_active (peer))
    return BGP_ERR_INVALID_FOR_PEER_GROUP_MEMBER;

  /* When unset the peer-group member's flag we have to check
     peer-group configuration.  */
  if (! set && peer_group_active (peer))
    if (CHECK_FLAG (peer->group->conf->flags, flag))
      {
	if (flag == PEER_FLAG_SHUTDOWN)
	  return BGP_ERR_PEER_GROUP_SHUTDOWN;
	else
	  return BGP_ERR_PEER_GROUP_HAS_THE_FLAG;
      }

  /* Flag conflict check.  */
  if (set
      && CHECK_FLAG (peer->flags | flag, PEER_FLAG_STRICT_CAP_MATCH)
      && CHECK_FLAG (peer->flags | flag, PEER_FLAG_OVERRIDE_CAPABILITY))
    return BGP_ERR_PEER_FLAG_CONFLICT;

  if (! CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    {
      if (set && CHECK_FLAG (peer->flags, flag) == flag)
	return 0;
      if (! set && ! CHECK_FLAG (peer->flags, flag))
	return 0;
    }

  if (set)
    SET_FLAG (peer->flags, flag);
  else
    UNSET_FLAG (peer->flags, flag);
 
  if (! CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
    {
      if (action.type == peer_change_reset)
	peer_flag_modify_action (peer, flag);

      return 0;
    }

  /* peer-group member updates. */
  group = peer->group;

  LIST_LOOP (group->peer, peer, nn)
    {
      if (set && CHECK_FLAG (peer->flags, flag) == flag)
	continue;

      if (! set && ! CHECK_FLAG (peer->flags, flag))
	continue;

      if (set)
	SET_FLAG (peer->flags, flag);
      else
	UNSET_FLAG (peer->flags, flag);

      if (action.type == peer_change_reset)
	peer_flag_modify_action (peer, flag);