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bgp_fsm.c
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/* BGP-4 Finite State Machine
* From RFC1771 [A Border Gateway Protocol 4 (BGP-4)]
* Copyright (C) 1996, 97, 98 Kunihiro Ishiguro
*
* 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 this program; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include "linklist.h"
#include "prefix.h"
#include "sockunion.h"
#include "thread.h"
#include "log.h"
#include "stream.h"
#include "ringbuf.h"
#include "memory.h"
#include "plist.h"
#include "workqueue.h"
#include "queue.h"
#include "filter.h"
#include "command.h"
#include "lib_errors.h"
#include "zclient.h"
#include "lib/json.h"
#include "bgpd/bgpd.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_debug.h"
#include "bgpd/bgp_errors.h"
#include "bgpd/bgp_fsm.h"
#include "bgpd/bgp_packet.h"
#include "bgpd/bgp_network.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_dump.h"
#include "bgpd/bgp_open.h"
#include "bgpd/bgp_advertise.h"
#include "bgpd/bgp_updgrp.h"
#include "bgpd/bgp_nht.h"
#include "bgpd/bgp_bfd.h"
#include "bgpd/bgp_memory.h"
#include "bgpd/bgp_keepalives.h"
#include "bgpd/bgp_io.h"
#include "bgpd/bgp_zebra.h"
DEFINE_HOOK(peer_backward_transition, (struct peer * peer), (peer))
DEFINE_HOOK(peer_status_changed, (struct peer * peer), (peer))
extern const char *get_afi_safi_str(afi_t afi, safi_t safi, bool for_json);
/* Definition of display strings corresponding to FSM events. This should be
* kept consistent with the events defined in bgpd.h
*/
static const char *const bgp_event_str[] = {
NULL,
"BGP_Start",
"BGP_Stop",
"TCP_connection_open",
"TCP_connection_closed",
"TCP_connection_open_failed",
"TCP_fatal_error",
"ConnectRetry_timer_expired",
"Hold_Timer_expired",
"KeepAlive_timer_expired",
"Receive_OPEN_message",
"Receive_KEEPALIVE_message",
"Receive_UPDATE_message",
"Receive_NOTIFICATION_message",
"Clearing_Completed",
};
/* BGP FSM (finite state machine) has three types of functions. Type
one is thread functions. Type two is event functions. Type three
is FSM functions. Timer functions are set by bgp_timer_set
function. */
/* BGP event function. */
int bgp_event(struct thread *);
/* BGP thread functions. */
static int bgp_start_timer(struct thread *);
static int bgp_connect_timer(struct thread *);
static int bgp_holdtime_timer(struct thread *);
/* BGP FSM functions. */
static int bgp_start(struct peer *);
/* Register peer with NHT */
static int bgp_peer_reg_with_nht(struct peer *peer)
{
int connected = 0;
if (peer->sort == BGP_PEER_EBGP && peer->ttl == BGP_DEFAULT_TTL
&& !CHECK_FLAG(peer->flags, PEER_FLAG_DISABLE_CONNECTED_CHECK)
&& !CHECK_FLAG(peer->bgp->flags, BGP_FLAG_DISABLE_NH_CONNECTED_CHK))
connected = 1;
return bgp_find_or_add_nexthop(
peer->bgp, peer->bgp, family2afi(peer->su.sa.sa_family),
NULL, peer, connected);
}
static void peer_xfer_stats(struct peer *peer_dst, struct peer *peer_src)
{
/* Copy stats over. These are only the pre-established state stats */
peer_dst->open_in += peer_src->open_in;
peer_dst->open_out += peer_src->open_out;
peer_dst->keepalive_in += peer_src->keepalive_in;
peer_dst->keepalive_out += peer_src->keepalive_out;
peer_dst->notify_in += peer_src->notify_in;
peer_dst->notify_out += peer_src->notify_out;
peer_dst->dynamic_cap_in += peer_src->dynamic_cap_in;
peer_dst->dynamic_cap_out += peer_src->dynamic_cap_out;
}
static struct peer *peer_xfer_conn(struct peer *from_peer)
{
struct peer *peer;
afi_t afi;
safi_t safi;
int fd;
enum bgp_fsm_status status, pstatus;
enum bgp_fsm_events last_evt, last_maj_evt;
assert(from_peer != NULL);
peer = from_peer->doppelganger;
if (!peer || !CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE))
return from_peer;
/*
* Let's check that we are not going to loose known configuration
* state based upon doppelganger rules.
*/
FOREACH_AFI_SAFI (afi, safi) {
if (from_peer->afc[afi][safi] != peer->afc[afi][safi]) {
flog_err(
EC_BGP_DOPPELGANGER_CONFIG,
"from_peer->afc[%d][%d] is not the same as what we are overwriting",
afi, safi);
return NULL;
}
}
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s: peer transfer %p fd %d -> %p fd %d)",
from_peer->host, from_peer, from_peer->fd, peer,
peer->fd);
bgp_writes_off(peer);
bgp_reads_off(peer);
bgp_writes_off(from_peer);
bgp_reads_off(from_peer);
/*
* Before exchanging FD remove doppelganger from
* keepalive peer hash. It could be possible conf peer
* fd is set to -1. If blocked on lock then keepalive
* thread can access peer pointer with fd -1.
*/
bgp_keepalives_off(from_peer);
BGP_TIMER_OFF(peer->t_routeadv);
BGP_TIMER_OFF(peer->t_connect);
BGP_TIMER_OFF(peer->t_connect_check_r);
BGP_TIMER_OFF(peer->t_connect_check_w);
BGP_TIMER_OFF(from_peer->t_routeadv);
BGP_TIMER_OFF(from_peer->t_connect);
BGP_TIMER_OFF(from_peer->t_connect_check_r);
BGP_TIMER_OFF(from_peer->t_connect_check_w);
BGP_TIMER_OFF(from_peer->t_process_packet);
/*
* At this point in time, it is possible that there are packets pending
* on various buffers. Those need to be transferred or dropped,
* otherwise we'll get spurious failures during session establishment.
*/
frr_with_mutex(&peer->io_mtx, &from_peer->io_mtx) {
fd = peer->fd;
peer->fd = from_peer->fd;
from_peer->fd = fd;
stream_fifo_clean(peer->ibuf);
stream_fifo_clean(peer->obuf);
/*
* this should never happen, since bgp_process_packet() is the
* only task that sets and unsets the current packet and it
* runs in our pthread.
*/
if (peer->curr) {
flog_err(
EC_BGP_PKT_PROCESS,
"[%s] Dropping pending packet on connection transfer:",
peer->host);
/* there used to be a bgp_packet_dump call here, but
* that's extremely confusing since there's no way to
* identify the packet in MRT dumps or BMP as dropped
* due to connection transfer.
*/
stream_free(peer->curr);
peer->curr = NULL;
}
// copy each packet from old peer's output queue to new peer
while (from_peer->obuf->head)
stream_fifo_push(peer->obuf,
stream_fifo_pop(from_peer->obuf));
// copy each packet from old peer's input queue to new peer
while (from_peer->ibuf->head)
stream_fifo_push(peer->ibuf,
stream_fifo_pop(from_peer->ibuf));
ringbuf_wipe(peer->ibuf_work);
ringbuf_copy(peer->ibuf_work, from_peer->ibuf_work,
ringbuf_remain(from_peer->ibuf_work));
}
peer->as = from_peer->as;
peer->v_holdtime = from_peer->v_holdtime;
peer->v_keepalive = from_peer->v_keepalive;
peer->v_routeadv = from_peer->v_routeadv;
peer->v_gr_restart = from_peer->v_gr_restart;
peer->cap = from_peer->cap;
status = peer->status;
pstatus = peer->ostatus;
last_evt = peer->last_event;
last_maj_evt = peer->last_major_event;
peer->status = from_peer->status;
peer->ostatus = from_peer->ostatus;
peer->last_event = from_peer->last_event;
peer->last_major_event = from_peer->last_major_event;
from_peer->status = status;
from_peer->ostatus = pstatus;
from_peer->last_event = last_evt;
from_peer->last_major_event = last_maj_evt;
peer->remote_id = from_peer->remote_id;
peer->last_reset = from_peer->last_reset;
peer->peer_gr_present_state = from_peer->peer_gr_present_state;
peer->peer_gr_new_status_flag = from_peer->peer_gr_new_status_flag;
bgp_peer_gr_flags_update(peer);
BGP_GR_ROUTER_DETECT_AND_SEND_CAPABILITY_TO_ZEBRA(peer->bgp,
peer->bgp->peer);
if (bgp_peer_gr_mode_get(peer) == PEER_DISABLE) {
UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
peer_nsf_stop(peer);
}
}
if (from_peer->hostname != NULL) {
if (peer->hostname) {
XFREE(MTYPE_BGP_PEER_HOST, peer->hostname);
peer->hostname = NULL;
}
peer->hostname = from_peer->hostname;
from_peer->hostname = NULL;
}
if (from_peer->domainname != NULL) {
if (peer->domainname) {
XFREE(MTYPE_BGP_PEER_HOST, peer->domainname);
peer->domainname = NULL;
}
peer->domainname = from_peer->domainname;
from_peer->domainname = NULL;
}
FOREACH_AFI_SAFI (afi, safi) {
peer->af_flags[afi][safi] = from_peer->af_flags[afi][safi];
peer->af_sflags[afi][safi] = from_peer->af_sflags[afi][safi];
peer->af_cap[afi][safi] = from_peer->af_cap[afi][safi];
peer->afc_nego[afi][safi] = from_peer->afc_nego[afi][safi];
peer->afc_adv[afi][safi] = from_peer->afc_adv[afi][safi];
peer->afc_recv[afi][safi] = from_peer->afc_recv[afi][safi];
peer->orf_plist[afi][safi] = from_peer->orf_plist[afi][safi];
}
if (bgp_getsockname(peer) < 0) {
flog_err(
EC_LIB_SOCKET,
"%%bgp_getsockname() failed for %s peer %s fd %d (from_peer fd %d)",
(CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)
? "accept"
: ""),
peer->host, peer->fd, from_peer->fd);
bgp_stop(peer);
bgp_stop(from_peer);
return NULL;
}
if (from_peer->status > Active) {
if (bgp_getsockname(from_peer) < 0) {
flog_err(
EC_LIB_SOCKET,
"%%bgp_getsockname() failed for %s from_peer %s fd %d (peer fd %d)",
(CHECK_FLAG(from_peer->sflags,
PEER_STATUS_ACCEPT_PEER)
? "accept"
: ""),
from_peer->host, from_peer->fd, peer->fd);
bgp_stop(from_peer);
from_peer = NULL;
}
}
// Note: peer_xfer_stats() must be called with I/O turned OFF
if (from_peer)
peer_xfer_stats(peer, from_peer);
/* Register peer for NHT. This is to allow RAs to be enabled when
* needed, even on a passive connection.
*/
bgp_peer_reg_with_nht(peer);
bgp_reads_on(peer);
bgp_writes_on(peer);
thread_add_timer_msec(bm->master, bgp_process_packet, peer, 0,
&peer->t_process_packet);
return (peer);
}
/* Hook function called after bgp event is occered. And vty's
neighbor command invoke this function after making neighbor
structure. */
void bgp_timer_set(struct peer *peer)
{
switch (peer->status) {
case Idle:
/* First entry point of peer's finite state machine. In Idle
status start timer is on unless peer is shutdown or peer is
inactive. All other timer must be turned off */
if (BGP_PEER_START_SUPPRESSED(peer) || !peer_active(peer)
|| (peer->bgp->inst_type != BGP_INSTANCE_TYPE_VIEW &&
peer->bgp->vrf_id == VRF_UNKNOWN)) {
BGP_TIMER_OFF(peer->t_start);
} else {
BGP_TIMER_ON(peer->t_start, bgp_start_timer,
peer->v_start);
}
BGP_TIMER_OFF(peer->t_connect);
BGP_TIMER_OFF(peer->t_holdtime);
bgp_keepalives_off(peer);
BGP_TIMER_OFF(peer->t_routeadv);
break;
case Connect:
/* After start timer is expired, the peer moves to Connect
status. Make sure start timer is off and connect timer is
on. */
BGP_TIMER_OFF(peer->t_start);
BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
peer->v_connect);
BGP_TIMER_OFF(peer->t_holdtime);
bgp_keepalives_off(peer);
BGP_TIMER_OFF(peer->t_routeadv);
break;
case Active:
/* Active is waiting connection from remote peer. And if
connect timer is expired, change status to Connect. */
BGP_TIMER_OFF(peer->t_start);
/* If peer is passive mode, do not set connect timer. */
if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)
|| CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
BGP_TIMER_OFF(peer->t_connect);
} else {
BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
peer->v_connect);
}
BGP_TIMER_OFF(peer->t_holdtime);
bgp_keepalives_off(peer);
BGP_TIMER_OFF(peer->t_routeadv);
break;
case OpenSent:
/* OpenSent status. */
BGP_TIMER_OFF(peer->t_start);
BGP_TIMER_OFF(peer->t_connect);
if (peer->v_holdtime != 0) {
BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
peer->v_holdtime);
} else {
BGP_TIMER_OFF(peer->t_holdtime);
}
bgp_keepalives_off(peer);
BGP_TIMER_OFF(peer->t_routeadv);
break;
case OpenConfirm:
/* OpenConfirm status. */
BGP_TIMER_OFF(peer->t_start);
BGP_TIMER_OFF(peer->t_connect);
/* If the negotiated Hold Time value is zero, then the Hold Time
timer and KeepAlive timers are not started. */
if (peer->v_holdtime == 0) {
BGP_TIMER_OFF(peer->t_holdtime);
bgp_keepalives_off(peer);
} else {
BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
peer->v_holdtime);
bgp_keepalives_on(peer);
}
BGP_TIMER_OFF(peer->t_routeadv);
break;
case Established:
/* In Established status start and connect timer is turned
off. */
BGP_TIMER_OFF(peer->t_start);
BGP_TIMER_OFF(peer->t_connect);
/* Same as OpenConfirm, if holdtime is zero then both holdtime
and keepalive must be turned off. */
if (peer->v_holdtime == 0) {
BGP_TIMER_OFF(peer->t_holdtime);
bgp_keepalives_off(peer);
} else {
BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
peer->v_holdtime);
bgp_keepalives_on(peer);
}
break;
case Deleted:
BGP_TIMER_OFF(peer->t_gr_restart);
BGP_TIMER_OFF(peer->t_gr_stale);
BGP_TIMER_OFF(peer->t_pmax_restart);
/* fallthru */
case Clearing:
BGP_TIMER_OFF(peer->t_start);
BGP_TIMER_OFF(peer->t_connect);
BGP_TIMER_OFF(peer->t_holdtime);
bgp_keepalives_off(peer);
BGP_TIMER_OFF(peer->t_routeadv);
break;
case BGP_STATUS_MAX:
flog_err(EC_LIB_DEVELOPMENT,
"BGP_STATUS_MAX while a legal state is not valid state for the FSM");
break;
}
}
/* BGP start timer. This function set BGP_Start event to thread value
and process event. */
static int bgp_start_timer(struct thread *thread)
{
struct peer *peer;
peer = THREAD_ARG(thread);
peer->t_start = NULL;
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s [FSM] Timer (start timer expire).", peer->host);
THREAD_VAL(thread) = BGP_Start;
bgp_event(thread); /* bgp_event unlocks peer */
return 0;
}
/* BGP connect retry timer. */
static int bgp_connect_timer(struct thread *thread)
{
struct peer *peer;
int ret;
peer = THREAD_ARG(thread);
assert(!peer->t_write);
assert(!peer->t_read);
peer->t_connect = NULL;
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s [FSM] Timer (connect timer expire)", peer->host);
if (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) {
bgp_stop(peer);
ret = -1;
} else {
THREAD_VAL(thread) = ConnectRetry_timer_expired;
bgp_event(thread); /* bgp_event unlocks peer */
ret = 0;
}
return ret;
}
/* BGP holdtime timer. */
static int bgp_holdtime_timer(struct thread *thread)
{
atomic_size_t inq_count;
struct peer *peer;
peer = THREAD_ARG(thread);
peer->t_holdtime = NULL;
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s [FSM] Timer (holdtime timer expire)",
peer->host);
/*
* Given that we do not have any expectation of ordering
* for handling packets from a peer -vs- handling
* the hold timer for a peer as that they are both
* events on the peer. If we have incoming
* data on the peers inq, let's give the system a chance
* to handle that data. This can be especially true
* for systems where we are heavily loaded for one
* reason or another.
*/
inq_count = atomic_load_explicit(&peer->ibuf->count,
memory_order_relaxed);
if (inq_count) {
BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
peer->v_holdtime);
return 0;
}
THREAD_VAL(thread) = Hold_Timer_expired;
bgp_event(thread); /* bgp_event unlocks peer */
return 0;
}
int bgp_routeadv_timer(struct thread *thread)
{
struct peer *peer;
peer = THREAD_ARG(thread);
peer->t_routeadv = NULL;
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s [FSM] Timer (routeadv timer expire)",
peer->host);
peer->synctime = bgp_clock();
thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets, peer, 0,
&peer->t_generate_updgrp_packets);
/* MRAI timer will be started again when FIFO is built, no need to
* do it here.
*/
return 0;
}
/* BGP Peer Down Cause */
const char *const peer_down_str[] = {"",
"Router ID changed",
"Remote AS changed",
"Local AS change",
"Cluster ID changed",
"Confederation identifier changed",
"Confederation peer changed",
"RR client config change",
"RS client config change",
"Update source change",
"Address family activated",
"Admin. shutdown",
"User reset",
"BGP Notification received",
"BGP Notification send",
"Peer closed the session",
"Neighbor deleted",
"Peer-group add member",
"Peer-group delete member",
"Capability changed",
"Passive config change",
"Multihop config change",
"NSF peer closed the session",
"Intf peering v6only config change",
"BFD down received",
"Interface down",
"Neighbor address lost",
"Waiting for NHT",
"Waiting for Peer IPv6 LLA",
"Waiting for VRF to be initialized",
"No AFI/SAFI activated for peer",
"AS Set config change",
"Waiting for peer OPEN",
"Reached received prefix count"};
static int bgp_graceful_restart_timer_expire(struct thread *thread)
{
struct peer *peer;
afi_t afi;
safi_t safi;
peer = THREAD_ARG(thread);
peer->t_gr_restart = NULL;
/* NSF delete stale route */
for (afi = AFI_IP; afi < AFI_MAX; afi++)
for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
if (peer->nsf[afi][safi])
bgp_clear_stale_route(peer, afi, safi);
UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
BGP_TIMER_OFF(peer->t_gr_stale);
if (bgp_debug_neighbor_events(peer)) {
zlog_debug("%s graceful restart timer expired", peer->host);
zlog_debug("%s graceful restart stalepath timer stopped",
peer->host);
}
bgp_timer_set(peer);
return 0;
}
static int bgp_graceful_stale_timer_expire(struct thread *thread)
{
struct peer *peer;
afi_t afi;
safi_t safi;
peer = THREAD_ARG(thread);
peer->t_gr_stale = NULL;
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s graceful restart stalepath timer expired",
peer->host);
/* NSF delete stale route */
for (afi = AFI_IP; afi < AFI_MAX; afi++)
for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
if (peer->nsf[afi][safi])
bgp_clear_stale_route(peer, afi, safi);
return 0;
}
/* Selection deferral timer processing function */
static int bgp_graceful_deferral_timer_expire(struct thread *thread)
{
struct afi_safi_info *info;
afi_t afi;
safi_t safi;
struct bgp *bgp;
info = THREAD_ARG(thread);
afi = info->afi;
safi = info->safi;
bgp = info->bgp;
if (BGP_DEBUG(update, UPDATE_OUT))
zlog_debug(
"afi %d, safi %d : graceful restart deferral timer expired",
afi, safi);
bgp->gr_info[afi][safi].t_select_deferral = NULL;
bgp->gr_info[afi][safi].eor_required = 0;
bgp->gr_info[afi][safi].eor_received = 0;
XFREE(MTYPE_TMP, info);
/* Best path selection */
return bgp_best_path_select_defer(bgp, afi, safi);
}
static bool bgp_update_delay_applicable(struct bgp *bgp)
{
/* update_delay_over flag should be reset (set to 0) for any new
applicability of the update-delay during BGP process lifetime.
And it should be set after an occurence of the update-delay is
over)*/
if (!bgp->update_delay_over)
return true;
return false;
}
bool bgp_update_delay_active(struct bgp *bgp)
{
if (bgp->t_update_delay)
return true;
return false;
}
bool bgp_update_delay_configured(struct bgp *bgp)
{
if (bgp->v_update_delay)
return true;
return false;
}
/* Do the post-processing needed when bgp comes out of the read-only mode
on ending the update delay. */
void bgp_update_delay_end(struct bgp *bgp)
{
THREAD_TIMER_OFF(bgp->t_update_delay);
THREAD_TIMER_OFF(bgp->t_establish_wait);
/* Reset update-delay related state */
bgp->update_delay_over = 1;
bgp->established = 0;
bgp->restarted_peers = 0;
bgp->implicit_eors = 0;
bgp->explicit_eors = 0;
quagga_timestamp(3, bgp->update_delay_end_time,
sizeof(bgp->update_delay_end_time));
/*
* Add an end-of-initial-update marker to the main process queues so
* that
* the route advertisement timer for the peers can be started. Also set
* the zebra and peer update hold flags. These flags are used to achieve
* three stages in the update-delay post processing:
* 1. Finish best-path selection for all the prefixes held on the
* queues.
* (routes in BGP are updated, and peers sync queues are populated
* too)
* 2. As the eoiu mark is reached in the bgp process routine, ship all
* the
* routes to zebra. With that zebra should see updates from BGP
* close
* to each other.
* 3. Unblock the peer update writes. With that peer update packing
* with
* the prefixes should be at its maximum.
*/
bgp_add_eoiu_mark(bgp);
bgp->main_zebra_update_hold = 1;
bgp->main_peers_update_hold = 1;
/* Resume the queue processing. This should trigger the event that would
take
care of processing any work that was queued during the read-only
mode. */
work_queue_unplug(bm->process_main_queue);
}
/**
* see bgp_fsm.h
*/
void bgp_start_routeadv(struct bgp *bgp)
{
struct listnode *node, *nnode;
struct peer *peer;
zlog_info("bgp_start_routeadv(), update hold status %d",
bgp->main_peers_update_hold);
if (bgp->main_peers_update_hold)
return;
quagga_timestamp(3, bgp->update_delay_peers_resume_time,
sizeof(bgp->update_delay_peers_resume_time));
for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
if (peer->status != Established)
continue;
BGP_TIMER_OFF(peer->t_routeadv);
BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
}
}
/**
* see bgp_fsm.h
*/
void bgp_adjust_routeadv(struct peer *peer)
{
time_t nowtime = bgp_clock();
double diff;
unsigned long remain;
/* Bypass checks for special case of MRAI being 0 */
if (peer->v_routeadv == 0) {
/* Stop existing timer, just in case it is running for a
* different
* duration and schedule write thread immediately.
*/
if (peer->t_routeadv)
BGP_TIMER_OFF(peer->t_routeadv);
peer->synctime = bgp_clock();
thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets,
peer, 0,
&peer->t_generate_updgrp_packets);
return;
}
/*
* CASE I:
* If the last update was written more than MRAI back, expire the timer
* instantly so that we can send the update out sooner.
*
* <------- MRAI --------->
* |-----------------|-----------------------|
* <------------- m ------------>
* ^ ^ ^
* | | |
* | | current time
* | timer start
* last write
*
* m > MRAI
*/
diff = difftime(nowtime, peer->last_update);
if (diff > (double)peer->v_routeadv) {
BGP_TIMER_OFF(peer->t_routeadv);
BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
return;
}
/*
* CASE II:
* - Find when to expire the MRAI timer.
* If MRAI timer is not active, assume we can start it now.
*
* <------- MRAI --------->
* |------------|-----------------------|
* <-------- m ----------><----- r ----->
* ^ ^ ^
* | | |
* | | current time
* | timer start
* last write
*
* (MRAI - m) < r
*/
if (peer->t_routeadv)
remain = thread_timer_remain_second(peer->t_routeadv);
else
remain = peer->v_routeadv;
diff = peer->v_routeadv - diff;
if (diff <= (double)remain) {
BGP_TIMER_OFF(peer->t_routeadv);
BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, diff);
}
}
static bool bgp_maxmed_onstartup_applicable(struct bgp *bgp)
{
if (!bgp->maxmed_onstartup_over)
return true;
return false;
}
bool bgp_maxmed_onstartup_configured(struct bgp *bgp)
{
if (bgp->v_maxmed_onstartup != BGP_MAXMED_ONSTARTUP_UNCONFIGURED)
return true;
return false;
}
bool bgp_maxmed_onstartup_active(struct bgp *bgp)
{
if (bgp->t_maxmed_onstartup)
return true;
return false;
}
void bgp_maxmed_update(struct bgp *bgp)
{
uint8_t maxmed_active;
uint32_t maxmed_value;
if (bgp->v_maxmed_admin) {
maxmed_active = 1;
maxmed_value = bgp->maxmed_admin_value;
} else if (bgp->t_maxmed_onstartup) {
maxmed_active = 1;
maxmed_value = bgp->maxmed_onstartup_value;
} else {
maxmed_active = 0;
maxmed_value = BGP_MAXMED_VALUE_DEFAULT;
}
if (bgp->maxmed_active != maxmed_active
|| bgp->maxmed_value != maxmed_value) {
bgp->maxmed_active = maxmed_active;
bgp->maxmed_value = maxmed_value;
update_group_announce(bgp);
}
}
int bgp_fsm_error_subcode(int status)
{
int fsm_err_subcode = BGP_NOTIFY_FSM_ERR_SUBCODE_UNSPECIFIC;
switch (status) {
case OpenSent:
fsm_err_subcode = BGP_NOTIFY_FSM_ERR_SUBCODE_OPENSENT;
break;
case OpenConfirm:
fsm_err_subcode = BGP_NOTIFY_FSM_ERR_SUBCODE_OPENCONFIRM;
break;
case Established:
fsm_err_subcode = BGP_NOTIFY_FSM_ERR_SUBCODE_ESTABLISHED;
break;
default:
break;
}
return fsm_err_subcode;
}
/* The maxmed onstartup timer expiry callback. */
static int bgp_maxmed_onstartup_timer(struct thread *thread)
{
struct bgp *bgp;
zlog_info("Max med on startup ended - timer expired.");
bgp = THREAD_ARG(thread);
THREAD_TIMER_OFF(bgp->t_maxmed_onstartup);
bgp->maxmed_onstartup_over = 1;
bgp_maxmed_update(bgp);
return 0;
}
static void bgp_maxmed_onstartup_begin(struct bgp *bgp)
{
/* Applicable only once in the process lifetime on the startup */
if (bgp->maxmed_onstartup_over)
return;
zlog_info("Begin maxmed onstartup mode - timer %d seconds",
bgp->v_maxmed_onstartup);
thread_add_timer(bm->master, bgp_maxmed_onstartup_timer, bgp,
bgp->v_maxmed_onstartup, &bgp->t_maxmed_onstartup);
if (!bgp->v_maxmed_admin) {
bgp->maxmed_active = 1;
bgp->maxmed_value = bgp->maxmed_onstartup_value;
}
/* Route announce to all peers should happen after this in
* bgp_establish() */
}
static void bgp_maxmed_onstartup_process_status_change(struct peer *peer)
{
if (peer->status == Established && !peer->bgp->established) {
bgp_maxmed_onstartup_begin(peer->bgp);
}
}
/* The update delay timer expiry callback. */
static int bgp_update_delay_timer(struct thread *thread)
{
struct bgp *bgp;
zlog_info("Update delay ended - timer expired.");
bgp = THREAD_ARG(thread);
THREAD_TIMER_OFF(bgp->t_update_delay);
bgp_update_delay_end(bgp);
return 0;
}
/* The establish wait timer expiry callback. */
static int bgp_establish_wait_timer(struct thread *thread)
{
struct bgp *bgp;
zlog_info("Establish wait - timer expired.");
bgp = THREAD_ARG(thread);
THREAD_TIMER_OFF(bgp->t_establish_wait);
bgp_check_update_delay(bgp);
return 0;
}
/* Steps to begin the update delay:
- initialize queues if needed