/* A route becomes unreachable (RFC2439 Section 4.8.2). */
int
bgp_damp_withdraw (struct bgp_info *binfo, struct bgp_node *rn,
afi_t afi, safi_t safi, int attr_change)
{
time_t t_now;
struct bgp_damp_info *bdi = NULL;
double last_penalty = 0;
t_now = bgp_clock ();
/* Processing Unreachable Messages. */
if (binfo->extra)
bdi = binfo->extra->damp_info;
if (bdi == NULL)
{
/* If there is no previous stability history. */
/* RFC2439 said:
1. allocate a damping structure.
2. set figure-of-merit = 1.
3. withdraw the route. */
bdi = XCALLOC (MTYPE_BGP_DAMP_INFO, sizeof (struct bgp_damp_info));
bdi->binfo = binfo;
bdi->rn = rn;
bdi->penalty = (attr_change ? DEFAULT_PENALTY / 2 : DEFAULT_PENALTY);
bdi->flap = 1;
bdi->start_time = t_now;
bdi->suppress_time = 0;
bdi->index = -1;
bdi->afi = afi;
bdi->safi = safi;
(bgp_info_extra_get (binfo))->damp_info = bdi;
BGP_DAMP_LIST_ADD (damp, bdi);
}
else
{
last_penalty = bdi->penalty;
/* 1. Set t-diff = t-now - t-updated. */
bdi->penalty =
(bgp_damp_decay (t_now - bdi->t_updated, bdi->penalty)
+ (attr_change ? DEFAULT_PENALTY / 2 : DEFAULT_PENALTY));
if (bdi->penalty > damp->ceiling)
bdi->penalty = damp->ceiling;
bdi->flap++;
}
assert ((rn == bdi->rn) && (binfo == bdi->binfo));
bdi->lastrecord = BGP_RECORD_WITHDRAW;
bdi->t_updated = t_now;
/* Make this route as historical status. */
bgp_info_set_flag (rn, binfo, BGP_INFO_HISTORY);
/* Remove the route from a reuse list if it is on one. */
if (CHECK_FLAG (bdi->binfo->flags, BGP_INFO_DAMPED))
{
/* If decay rate isn't equal to 0, reinsert brn. */
if (bdi->penalty != last_penalty)
{
bgp_reuse_list_delete (bdi);
bgp_reuse_list_add (bdi);
}
return BGP_DAMP_SUPPRESSED;
}
/* If not suppressed before, do annonunce this withdraw and
insert into reuse_list. */
if (bdi->penalty >= damp->suppress_value)
{
bgp_info_set_flag (rn, binfo, BGP_INFO_DAMPED);
bdi->suppress_time = t_now;
BGP_DAMP_LIST_DEL (damp, bdi);
bgp_reuse_list_add (bdi);
}
return BGP_DAMP_USED;
}
static void
bgp_scan (afi_t afi, safi_t safi)
{
struct bgp_node *rn;
struct bgp *bgp;
struct bgp_info *bi;
struct bgp_info *next;
struct peer *peer;
struct listnode *node, *nnode;
int valid;
int current;
int changed;
int metricchanged;
/* Change cache. */
if (bgp_nexthop_cache_table[afi] == cache1_table[afi])
bgp_nexthop_cache_table[afi] = cache2_table[afi];
else
bgp_nexthop_cache_table[afi] = cache1_table[afi];
/* Get default bgp. */
bgp = bgp_get_default ();
if (bgp == NULL)
return;
/* Maximum prefix check */
for (ALL_LIST_ELEMENTS (bgp->peer, node, nnode, peer))
{
if (peer->status != Established)
continue;
if (peer->afc[afi][SAFI_UNICAST])
bgp_maximum_prefix_overflow (peer, afi, SAFI_UNICAST, 1);
if (peer->afc[afi][SAFI_MULTICAST])
bgp_maximum_prefix_overflow (peer, afi, SAFI_MULTICAST, 1);
if (peer->afc[afi][SAFI_MPLS_VPN])
bgp_maximum_prefix_overflow (peer, afi, SAFI_MPLS_VPN, 1);
}
for (rn = bgp_table_top (bgp->rib[afi][SAFI_UNICAST]); rn;
rn = bgp_route_next (rn))
{
for (bi = rn->info; bi; bi = next)
{
next = bi->next;
if (bi->type == ZEBRA_ROUTE_BGP && bi->sub_type == BGP_ROUTE_NORMAL)
{
changed = 0;
metricchanged = 0;
if (bi->peer->sort == BGP_PEER_EBGP && bi->peer->ttl == 1)
valid = bgp_nexthop_onlink (afi, bi->attr);
else
valid = bgp_nexthop_lookup (afi, bi->peer, bi,
&changed, &metricchanged);
current = CHECK_FLAG (bi->flags, BGP_INFO_VALID) ? 1 : 0;
if (changed)
SET_FLAG (bi->flags, BGP_INFO_IGP_CHANGED);
else
UNSET_FLAG (bi->flags, BGP_INFO_IGP_CHANGED);
if (valid != current)
{
if (CHECK_FLAG (bi->flags, BGP_INFO_VALID))
{
bgp_aggregate_decrement (bgp, &rn->p, bi,
afi, SAFI_UNICAST);
bgp_info_unset_flag (rn, bi, BGP_INFO_VALID);
}
else
{
bgp_info_set_flag (rn, bi, BGP_INFO_VALID);
bgp_aggregate_increment (bgp, &rn->p, bi,
afi, SAFI_UNICAST);
}
}
if (CHECK_FLAG (bgp->af_flags[afi][SAFI_UNICAST],
BGP_CONFIG_DAMPENING)
&& bi->extra && bi->extra->damp_info )
if (bgp_damp_scan (bi, afi, SAFI_UNICAST))
bgp_aggregate_increment (bgp, &rn->p, bi,
afi, SAFI_UNICAST);
}
}
bgp_process (bgp, rn, afi, SAFI_UNICAST);
}
/* Flash old cache. */
if (bgp_nexthop_cache_table[afi] == cache1_table[afi])
bgp_nexthop_cache_reset (cache2_table[afi]);
else
bgp_nexthop_cache_reset (cache1_table[afi]);
if (BGP_DEBUG (events, EVENTS))
{
if (afi == AFI_IP)
zlog_debug ("scanning IPv4 Unicast routing tables");
else if (afi == AFI_IP6)
zlog_debug ("scanning IPv6 Unicast routing tables");
}
/* Reevaluate default-originate route-maps and announce/withdraw
* default route if neccesary. */
for (ALL_LIST_ELEMENTS (bgp->peer, node, nnode, peer))
{
if (peer->status == Established
&& CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_DEFAULT_ORIGINATE)
&& peer->default_rmap[afi][safi].name)
bgp_default_originate (peer, afi, safi, 0);
}
}
