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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 "memory.h"
#include "plist.h"
#include "workqueue.h"
#include "queue.h"
#include "filter.h"
#include "command.h"
#include "lib/json.h"
#include "bgpd/bgpd.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_debug.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"
DEFINE_HOOK(peer_backward_transition, (struct peer * peer), (peer))
DEFINE_HOOK(peer_established, (struct peer * peer), (peer))
/* Definition of display strings corresponding to FSM events. This should be
* kept consistent with the events defined in bgpd.h
*/
static const char *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 *);
static int bgp_keepalive_timer(struct thread *);
/* BGP FSM functions. */
static int bgp_start(struct peer *);
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;
int status, pstatus;
unsigned char 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;
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_WRITE_OFF(peer->t_write);
BGP_READ_OFF(peer->t_read);
BGP_WRITE_OFF(from_peer->t_write);
BGP_READ_OFF(from_peer->t_read);
BGP_TIMER_OFF(peer->t_routeadv);
BGP_TIMER_OFF(from_peer->t_routeadv);
fd = peer->fd;
peer->fd = from_peer->fd;
from_peer->fd = fd;
stream_reset(peer->ibuf);
stream_fifo_clean(peer->obuf);
stream_fifo_clean(from_peer->obuf);
peer->as = from_peer->as;
peer->v_holdtime = from_peer->v_holdtime;
peer->v_keepalive = from_peer->v_keepalive;
peer->routeadv = from_peer->routeadv;
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;
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;
}
for (afi = AFI_IP; afi < AFI_MAX; afi++)
for (safi = SAFI_UNICAST; safi < SAFI_MAX; 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) {
zlog_err(
"%%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) {
zlog_err(
"%%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;
}
}
BGP_READ_ON(peer->t_read, bgp_read, peer->fd);
BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
if (from_peer)
peer_xfer_stats(peer, from_peer);
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)) {
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_TIMER_OFF(peer->t_keepalive);
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_TIMER_OFF(peer->t_keepalive);
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_TIMER_OFF(peer->t_keepalive);
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_TIMER_OFF(peer->t_keepalive);
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_TIMER_OFF(peer->t_keepalive);
} else {
BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
peer->v_holdtime);
BGP_TIMER_ON(peer->t_keepalive, bgp_keepalive_timer,
peer->v_keepalive);
}
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_TIMER_OFF(peer->t_keepalive);
} else {
BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
peer->v_holdtime);
BGP_TIMER_ON(peer->t_keepalive, bgp_keepalive_timer,
peer->v_keepalive);
}
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_TIMER_OFF(peer->t_keepalive);
BGP_TIMER_OFF(peer->t_routeadv);
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);
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)
{
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);
THREAD_VAL(thread) = Hold_Timer_expired;
bgp_event(thread); /* bgp_event unlocks peer */
return 0;
}
/* BGP keepalive fire ! */
static int bgp_keepalive_timer(struct thread *thread)
{
struct peer *peer;
peer = THREAD_ARG(thread);
peer->t_keepalive = NULL;
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s [FSM] Timer (keepalive timer expire)",
peer->host);
THREAD_VAL(thread) = KeepAlive_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();
BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
/* MRAI timer will be started again when FIFO is built, no need to
* do it here.
*/
return 0;
}
/* BGP Peer Down Cause */
const char *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"};
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_RESERVED_4; 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_RESERVED_4; safi++)
if (peer->nsf[afi][safi])
bgp_clear_stale_route(peer, afi, safi);
return 0;
}
static int 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 1;
return 0;
}
int bgp_update_delay_active(struct bgp *bgp)
{
if (bgp->t_update_delay)
return 1;
return 0;
}
int bgp_update_delay_configured(struct bgp *bgp)
{
if (bgp->v_update_delay)
return 1;
return 0;
}
/* 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();
BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
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 int bgp_maxmed_onstartup_applicable(struct bgp *bgp)
{
if (!bgp->maxmed_onstartup_over)
return 1;
return 0;
}
int bgp_maxmed_onstartup_configured(struct bgp *bgp)
{
if (bgp->v_maxmed_onstartup != BGP_MAXMED_ONSTARTUP_UNCONFIGURED)
return 1;
return 0;
}
int bgp_maxmed_onstartup_active(struct bgp *bgp)
{
if (bgp->t_maxmed_onstartup)
return 1;
return 0;
}
void bgp_maxmed_update(struct bgp *bgp)
{
u_char maxmed_active;
u_int32_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);
}
}
/* 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
- stop the queue processing
- start the timer */
static void bgp_update_delay_begin(struct bgp *bgp)
{
struct listnode *node, *nnode;
struct peer *peer;
/* Stop the processing of queued work. Enqueue shall continue */
work_queue_plug(bm->process_main_queue);
for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer))
peer->update_delay_over = 0;
/* Start the update-delay timer */
thread_add_timer(bm->master, bgp_update_delay_timer, bgp,
bgp->v_update_delay, &bgp->t_update_delay);
if (bgp->v_establish_wait != bgp->v_update_delay)
thread_add_timer(bm->master, bgp_establish_wait_timer, bgp,
bgp->v_establish_wait, &bgp->t_establish_wait);
quagga_timestamp(3, bgp->update_delay_begin_time,
sizeof(bgp->update_delay_begin_time));
}
static void bgp_update_delay_process_status_change(struct peer *peer)
{
if (peer->status == Established) {
if (!peer->bgp->established++) {
bgp_update_delay_begin(peer->bgp);
zlog_info(
"Begin read-only mode - update-delay timer %d seconds",
peer->bgp->v_update_delay);
}
if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_BIT_RCV))
bgp_update_restarted_peers(peer);
}
if (peer->ostatus == Established
&& bgp_update_delay_active(peer->bgp)) {
/* Adjust the update-delay state to account for this flap.
NOTE: Intentionally skipping adjusting implicit_eors or
explicit_eors
counters. Extra sanity check in bgp_check_update_delay()
should
be enough to take care of any additive discrepancy in bgp eor
counters */
peer->bgp->established--;
peer->update_delay_over = 0;
}
}
/* Called after event occured, this function change status and reset
read/write and timer thread. */
void bgp_fsm_change_status(struct peer *peer, int status)
{
bgp_dump_state(peer, peer->status, status);
/* Transition into Clearing or Deleted must /always/ clear all routes..
* (and must do so before actually changing into Deleted..
*/
if (status >= Clearing) {
bgp_clear_route_all(peer);
/* If no route was queued for the clear-node processing,
* generate the
* completion event here. This is needed because if there are no
* routes
* to trigger the background clear-node thread, the event won't
* get
* generated and the peer would be stuck in Clearing. Note that
* this
* event is for the peer and helps the peer transition out of
* Clearing
* state; it should not be generated per (AFI,SAFI). The event
* is
* directly posted here without calling clear_node_complete() as
* we
* shouldn't do an extra unlock. This event will get processed
* after
* the state change that happens below, so peer will be in
* Clearing
* (or Deleted).
*/
if (!work_queue_is_scheduled(peer->clear_node_queue))
BGP_EVENT_ADD(peer, Clearing_Completed);
}
/* Preserve old status and change into new status. */
peer->ostatus = peer->status;
peer->status = status;
/* Save event that caused status change. */
peer->last_major_event = peer->cur_event;
if (status == Established)
UNSET_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER);
/* If max-med processing is applicable, do the necessary. */
if (status == Established) {
if (bgp_maxmed_onstartup_configured(peer->bgp)
&& bgp_maxmed_onstartup_applicable(peer->bgp))
bgp_maxmed_onstartup_process_status_change(peer);
else
peer->bgp->maxmed_onstartup_over = 1;
}
/* If update-delay processing is applicable, do the necessary. */
if (bgp_update_delay_configured(peer->bgp)
&& bgp_update_delay_applicable(peer->bgp))
bgp_update_delay_process_status_change(peer);
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s went from %s to %s", peer->host,
lookup_msg(bgp_status_msg, peer->ostatus, NULL),
lookup_msg(bgp_status_msg, peer->status, NULL));
}
/* Flush the event queue and ensure the peer is shut down */
static int bgp_clearing_completed(struct peer *peer)
{
int rc = bgp_stop(peer);
if (rc >= 0)
BGP_EVENT_FLUSH(peer);
return rc;
}
/* Administrative BGP peer stop event. */
/* May be called multiple times for the same peer */
int bgp_stop(struct peer *peer)
{
afi_t afi;
safi_t safi;
char orf_name[BUFSIZ];
int ret = 0;
if (peer_dynamic_neighbor(peer)
&& !(CHECK_FLAG(peer->flags, PEER_FLAG_DELETE))) {
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s (dynamic neighbor) deleted", peer->host);
peer_delete(peer);
return -1;
}
/* Can't do this in Clearing; events are used for state transitions */
if (peer->status != Clearing) {
/* Delete all existing events of the peer */
BGP_EVENT_FLUSH(peer);
}
/* Increment Dropped count. */
if (peer->status == Established) {
peer->dropped++;
/* bgp log-neighbor-changes of neighbor Down */
if (bgp_flag_check(peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES)) {
struct vrf *vrf = vrf_lookup_by_id(peer->bgp->vrf_id);
zlog_info(
"%%ADJCHANGE: neighbor %s(%s) in vrf %s Down %s",
peer->host,
(peer->hostname) ? peer->hostname : "Unknown",
vrf ? ((vrf->vrf_id != VRF_DEFAULT) ? vrf->name
: "Default")
: "",
peer_down_str[(int)peer->last_reset]);
}
/* graceful restart */
if (peer->t_gr_stale) {
BGP_TIMER_OFF(peer->t_gr_stale);
if (bgp_debug_neighbor_events(peer))