[bgpd] Fix 0.99 shutdown regression, introduce Clearing and Deleted states
2006-09-14 Paul Jakma <paul.jakma@sun.com>
* (general) Fix some niggly issues around 'shutdown' and clearing
by adding a Clearing FSM wait-state and a hidden 'Deleted'
FSM state, to allow deleted peers to 'cool off' and hit 0
references. This introduces a slow memory leak of struct peer,
however that's more a testament to the fragility of the
reference counting than a bug in this patch, cleanup of
reference counting to fix this is to follow.
* bgpd.h: Add Clearing, Deleted states and Clearing_Completed
and event.
* bgp_debug.c: (bgp_status_msg[]) Add strings for Clearing and
Deleted.
* bgp_fsm.h: Don't allow timer/event threads to set anything
for Deleted peers.
* bgp_fsm.c: (bgp_timer_set) Add Clearing and Deleted. Deleted
needs to stop everything.
(bgp_stop) Remove explicit fsm_change_status call, the
general framework handles the transition.
(bgp_start) Log a warning if a start is attempted on a peer
that should stay down, trying to start a peer.
(struct .. FSM) Add Clearing_Completed
events, has little influence except when in state
Clearing to signal wait-state can end.
Add Clearing and Deleted states, former is a wait-state,
latter is a placeholder state to allow peers to disappear
quietly once refcounts settle.
(bgp_event) Try reduce verbosity of FSM state-change debug,
changes to same state are not interesting (Established->Established)
Allow NULL action functions in FSM.
* bgp_packet.c: (bgp_write) Use FSM events, rather than trying
to twiddle directly with FSM state behind the back of FSM.
(bgp_write_notify) ditto.
(bgp_read) Remove the vague ACCEPT_PEER peer_unlock, or else
this patch crashes, now it leaks instead.
* bgp_route.c: (bgp_clear_node_complete) Clearing_Completed
event, to end clearing.
(bgp_clear_route) See extensive comments.
* bgpd.c: (peer_free) should only be called while in Deleted,
peer refcounting controls when peer_free is called.
bgp_sync_delete should be here, not in peer_delete.
(peer_delete) Initiate delete.
Transition to Deleted state manually.
When removing peer from indices that provide visibility of it,
take great care to be idempotent wrt the reference counting
of struct peer through those indices.
Use bgp_timer_set, rather than replicating.
Call to bgp_sync_delete isn't appropriate here, sync can be
referenced while shutting down and finishing deletion.
(peer_group_bind) Take care to be idempotent wrt list references
indexing peers.
diff --git a/bgpd/ChangeLog b/bgpd/ChangeLog
index 482beed..02aaf3a 100644
--- a/bgpd/ChangeLog
+++ b/bgpd/ChangeLog
@@ -1,3 +1,55 @@
+2006-09-14 Paul Jakma <paul.jakma@sun.com>
+
+ * (general) Fix some niggly issues around 'shutdown' and clearing
+ by adding a Clearing FSM wait-state and a hidden 'Deleted'
+ FSM state, to allow deleted peers to 'cool off' and hit 0
+ references. This introduces a slow memory leak of struct peer,
+ however that's more a testament to the fragility of the
+ reference counting than a bug in this patch, cleanup of
+ reference counting to fix this is to follow.
+ * bgpd.h: Add Clearing, Deleted states and Clearing_Completed
+ and event.
+ * bgp_debug.c: (bgp_status_msg[]) Add strings for Clearing and
+ Deleted.
+ * bgp_fsm.h: Don't allow timer/event threads to set anything
+ for Deleted peers.
+ * bgp_fsm.c: (bgp_timer_set) Add Clearing and Deleted. Deleted
+ needs to stop everything.
+ (bgp_stop) Remove explicit fsm_change_status call, the
+ general framework handles the transition.
+ (bgp_start) Log a warning if a start is attempted on a peer
+ that should stay down, trying to start a peer.
+ (struct .. FSM) Add Clearing_Completed
+ events, has little influence except when in state
+ Clearing to signal wait-state can end.
+ Add Clearing and Deleted states, former is a wait-state,
+ latter is a placeholder state to allow peers to disappear
+ quietly once refcounts settle.
+ (bgp_event) Try reduce verbosity of FSM state-change debug,
+ changes to same state are not interesting (Established->Established)
+ Allow NULL action functions in FSM.
+ * bgp_packet.c: (bgp_write) Use FSM events, rather than trying
+ to twiddle directly with FSM state behind the back of FSM.
+ (bgp_write_notify) ditto.
+ (bgp_read) Remove the vague ACCEPT_PEER peer_unlock, or else
+ this patch crashes, now it leaks instead.
+ * bgp_route.c: (bgp_clear_node_complete) Clearing_Completed
+ event, to end clearing.
+ (bgp_clear_route) See extensive comments.
+ * bgpd.c: (peer_free) should only be called while in Deleted,
+ peer refcounting controls when peer_free is called.
+ bgp_sync_delete should be here, not in peer_delete.
+ (peer_delete) Initiate delete.
+ Transition to Deleted state manually.
+ When removing peer from indices that provide visibility of it,
+ take great care to be idempotent wrt the reference counting
+ of struct peer through those indices.
+ Use bgp_timer_set, rather than replicating.
+ Call to bgp_sync_delete isn't appropriate here, sync can be
+ referenced while shutting down and finishing deletion.
+ (peer_group_bind) Take care to be idempotent wrt list references
+ indexing peers.
+
2006-09-13 Paul Jakma <paul.jakma@sun.com>
* bgp_aspath.c: (aspath_highest) new, return highest ASN in an
diff --git a/bgpd/bgp_debug.c b/bgpd/bgp_debug.c
index 1b398ee..1e0fcd1 100644
--- a/bgpd/bgp_debug.c
+++ b/bgpd/bgp_debug.c
@@ -62,6 +62,8 @@
{ OpenSent, "OpenSent" },
{ OpenConfirm, "OpenConfirm" },
{ Established, "Established" },
+ { Clearing, "Clearing" },
+ { Deleted, "Deleted" },
};
int bgp_status_msg_max = BGP_STATUS_MAX;
diff --git a/bgpd/bgp_fsm.c b/bgpd/bgp_fsm.c
index 770a791..bdb6517 100644
--- a/bgpd/bgp_fsm.c
+++ b/bgpd/bgp_fsm.c
@@ -68,6 +68,11 @@
return ((rand () % (time + 1)) - (time / 2));
}
+/* Check if suppress start/restart of sessions to peer. */
+#define BGP_PEER_START_SUPPRESSED(P) \
+ (CHECK_FLAG ((P)->flags, PEER_FLAG_SHUTDOWN) \
+ || CHECK_FLAG ((P)->sflags, PEER_STATUS_PREFIX_OVERFLOW))
+
/* Hook function called after bgp event is occered. And vty's
neighbor command invoke this function after making neighbor
structure. */
@@ -82,10 +87,7 @@
/* 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 (CHECK_FLAG (peer->flags, PEER_FLAG_SHUTDOWN)
- || CHECK_FLAG (peer->sflags, PEER_STATUS_PREFIX_OVERFLOW)
- || CHECK_FLAG (peer->sflags, PEER_STATUS_CLEARING)
- || ! peer_active (peer))
+ if (BGP_PEER_START_SUPPRESSED (peer) || ! peer_active (peer))
{
BGP_TIMER_OFF (peer->t_start);
}
@@ -197,6 +199,17 @@
}
BGP_TIMER_OFF (peer->t_asorig);
break;
+ case Deleted:
+ BGP_TIMER_OFF (peer->t_gr_restart);
+ BGP_TIMER_OFF (peer->t_gr_stale);
+ BGP_TIMER_OFF (peer->t_pmax_restart);
+ 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_asorig);
+ BGP_TIMER_OFF (peer->t_routeadv);
}
}
@@ -420,7 +433,6 @@
if (peer->status == Established)
{
peer->dropped++;
- bgp_fsm_change_status (peer, Idle);
/* bgp log-neighbor-changes of neighbor Down */
if (bgp_flag_check (peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES))
@@ -625,6 +637,14 @@
{
int status;
+ if (BGP_PEER_START_SUPPRESSED (peer))
+ {
+ if (BGP_DEBUG (fsm, FSM))
+ plog_err (peer->log, "%s [FSM] Trying to start suppressed peer"
+ " - this is never supposed to happen!", peer->host);
+ return -1;
+ }
+
/* Scrub some information that might be left over from a previous,
* session
*/
@@ -903,6 +923,7 @@
{bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
{bgp_ignore, Idle}, /* Receive_UPDATE_message */
{bgp_ignore, Idle}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Idle}, /* Clearing_Completed */
},
{
/* Connect */
@@ -919,6 +940,7 @@
{bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
{bgp_ignore, Idle}, /* Receive_UPDATE_message */
{bgp_stop, Idle}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Idle}, /* Clearing_Completed */
},
{
/* Active, */
@@ -935,6 +957,7 @@
{bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
{bgp_ignore, Idle}, /* Receive_UPDATE_message */
{bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Idle}, /* Clearing_Completed */
},
{
/* OpenSent, */
@@ -951,6 +974,7 @@
{bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
{bgp_ignore, Idle}, /* Receive_UPDATE_message */
{bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Idle}, /* Clearing_Completed */
},
{
/* OpenConfirm, */
@@ -967,22 +991,58 @@
{bgp_establish, Established}, /* Receive_KEEPALIVE_message */
{bgp_ignore, Idle}, /* Receive_UPDATE_message */
{bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Idle}, /* Clearing_Completed */
},
{
/* Established, */
- {bgp_ignore, Established}, /* BGP_Start */
- {bgp_stop, Idle}, /* BGP_Stop */
- {bgp_stop, Idle}, /* TCP_connection_open */
- {bgp_stop, Idle}, /* TCP_connection_closed */
- {bgp_ignore, Idle}, /* TCP_connection_open_failed */
- {bgp_stop, Idle}, /* TCP_fatal_error */
- {bgp_ignore, Idle}, /* ConnectRetry_timer_expired */
- {bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
+ {bgp_ignore, Established}, /* BGP_Start */
+ {bgp_stop, Clearing}, /* BGP_Stop */
+ {bgp_stop, Clearing}, /* TCP_connection_open */
+ {bgp_stop, Clearing}, /* TCP_connection_closed */
+ {bgp_ignore, Clearing}, /* TCP_connection_open_failed */
+ {bgp_stop, Clearing}, /* TCP_fatal_error */
+ {bgp_ignore, Clearing}, /* ConnectRetry_timer_expired */
+ {bgp_fsm_holdtime_expire, Clearing}, /* Hold_Timer_expired */
{bgp_fsm_keepalive_expire, Established}, /* KeepAlive_timer_expired */
- {bgp_stop, Idle}, /* Receive_OPEN_message */
- {bgp_fsm_keepalive, Established}, /* Receive_KEEPALIVE_message */
- {bgp_fsm_update, Established}, /* Receive_UPDATE_message */
- {bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
+ {bgp_stop, Clearing}, /* Receive_OPEN_message */
+ {bgp_fsm_keepalive, Established}, /* Receive_KEEPALIVE_message */
+ {bgp_fsm_update, Established}, /* Receive_UPDATE_message */
+ {bgp_stop_with_error, Clearing}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Idle}, /* Clearing_Completed */
+ },
+ {
+ /* Clearing, */
+ {bgp_ignore, Clearing}, /* BGP_Start */
+ {bgp_ignore, Clearing}, /* BGP_Stop */
+ {bgp_ignore, Clearing}, /* TCP_connection_open */
+ {bgp_ignore, Clearing}, /* TCP_connection_closed */
+ {bgp_ignore, Clearing}, /* TCP_connection_open_failed */
+ {bgp_ignore, Clearing}, /* TCP_fatal_error */
+ {bgp_ignore, Clearing}, /* ConnectRetry_timer_expired */
+ {bgp_ignore, Clearing}, /* Hold_Timer_expired */
+ {bgp_ignore, Clearing}, /* KeepAlive_timer_expired */
+ {bgp_ignore, Clearing}, /* Receive_OPEN_message */
+ {bgp_ignore, Clearing}, /* Receive_KEEPALIVE_message */
+ {bgp_ignore, Clearing}, /* Receive_UPDATE_message */
+ {bgp_ignore, Clearing}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Idle }, /* Clearing_Completed */
+ },
+ {
+ /* Deleted, */
+ {bgp_ignore, Deleted}, /* BGP_Start */
+ {bgp_ignore, Deleted}, /* BGP_Stop */
+ {bgp_ignore, Deleted}, /* TCP_connection_open */
+ {bgp_ignore, Deleted}, /* TCP_connection_closed */
+ {bgp_ignore, Deleted}, /* TCP_connection_open_failed */
+ {bgp_ignore, Deleted}, /* TCP_fatal_error */
+ {bgp_ignore, Deleted}, /* ConnectRetry_timer_expired */
+ {bgp_ignore, Deleted}, /* Hold_Timer_expired */
+ {bgp_ignore, Deleted}, /* KeepAlive_timer_expired */
+ {bgp_ignore, Deleted}, /* Receive_OPEN_message */
+ {bgp_ignore, Deleted}, /* Receive_KEEPALIVE_message */
+ {bgp_ignore, Deleted}, /* Receive_UPDATE_message */
+ {bgp_ignore, Deleted}, /* Receive_NOTIFICATION_message */
+ {bgp_ignore, Deleted}, /* Clearing_Completed */
},
};
@@ -1001,14 +1061,15 @@
"Receive_OPEN_message",
"Receive_KEEPALIVE_message",
"Receive_UPDATE_message",
- "Receive_NOTIFICATION_message"
+ "Receive_NOTIFICATION_message",
+ "Clearing_Completed",
};
/* Execute event process. */
int
bgp_event (struct thread *thread)
{
- int ret;
+ int ret = 0;
int event;
int next;
struct peer *peer;
@@ -1019,14 +1080,15 @@
/* Logging this event. */
next = FSM [peer->status -1][event - 1].next_state;
- if (BGP_DEBUG (fsm, FSM))
+ if (BGP_DEBUG (fsm, FSM) && peer->status != next)
plog_debug (peer->log, "%s [FSM] %s (%s->%s)", peer->host,
bgp_event_str[event],
LOOKUP (bgp_status_msg, peer->status),
LOOKUP (bgp_status_msg, next));
/* Call function. */
- ret = (*(FSM [peer->status - 1][event - 1].func))(peer);
+ if (FSM [peer->status -1][event - 1].func)
+ ret = (*(FSM [peer->status - 1][event - 1].func))(peer);
/* When function do not want proceed next job return -1. */
if (ret >= 0)
diff --git a/bgpd/bgp_fsm.h b/bgpd/bgp_fsm.h
index e90f3b4..0a5d371 100644
--- a/bgpd/bgp_fsm.h
+++ b/bgpd/bgp_fsm.h
@@ -43,7 +43,7 @@
#define BGP_WRITE_ON(T,F,V) \
do { \
- if (!T) \
+ if (!(T) && (peer->status != Deleted)) \
{ \
peer_lock (peer); \
THREAD_WRITE_ON(master,(T),(F),peer,(V)); \
@@ -61,7 +61,7 @@
#define BGP_TIMER_ON(T,F,V) \
do { \
- if (!T) \
+ if (!(T) && (peer->status != Deleted)) \
{ \
peer_lock (peer); \
THREAD_TIMER_ON(master,(T),(F),peer,(V)); \
@@ -79,8 +79,11 @@
#define BGP_EVENT_ADD(P,E) \
do { \
- peer_lock (peer); /* bgp event reference */ \
- thread_add_event (master, bgp_event, (P), (E)); \
+ if ((P)->status != Deleted) \
+ { \
+ peer_lock (peer); /* bgp event reference */ \
+ thread_add_event (master, bgp_event, (P), (E)); \
+ } \
} while (0)
#define BGP_EVENT_DELETE(P) \
@@ -90,6 +93,12 @@
thread_cancel_event (master, (P)); \
} while (0)
+#define BGP_EVENT_FLUSH_ADD(P,E) \
+ do { \
+ BGP_EVENT_DELETE(P); \
+ BGP_EVENT_ADD(P,E); \
+ } while (0)
+
/* Prototypes. */
extern int bgp_event (struct thread *);
extern int bgp_stop (struct peer *peer);
diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c
index 8b024a1..da59d32 100644
--- a/bgpd/bgp_packet.c
+++ b/bgpd/bgp_packet.c
@@ -637,9 +637,7 @@
if (write_errno == EWOULDBLOCK || write_errno == EAGAIN)
break;
- BGP_EVENT_ADD (peer, BGP_Stop);
- peer->status = Idle;
- bgp_timer_set (peer);
+ BGP_EVENT_FLUSH_ADD (peer, TCP_fatal_error);
return 0;
}
if (num != writenum)
@@ -673,10 +671,8 @@
if (peer->v_start >= (60 * 2))
peer->v_start = (60 * 2);
- BGP_EVENT_ADD (peer, BGP_Stop);
- /*bgp_stop (peer);*/
- peer->status = Idle;
- bgp_timer_set (peer);
+ /* Flush any existing events */
+ BGP_EVENT_FLUSH_ADD (peer, BGP_Stop);
return 0;
case BGP_MSG_KEEPALIVE:
peer->keepalive_out++;
@@ -721,9 +717,7 @@
ret = writen (peer->fd, STREAM_DATA (s), stream_get_endp (s));
if (ret <= 0)
{
- BGP_EVENT_ADD (peer, BGP_Stop);
- peer->status = Idle;
- bgp_timer_set (peer);
+ BGP_EVENT_FLUSH_ADD (peer, TCP_fatal_error);
return 0;
}
@@ -743,10 +737,7 @@
if (peer->v_start >= (60 * 2))
peer->v_start = (60 * 2);
- /* We don't call event manager at here for avoiding other events. */
- bgp_stop (peer);
- peer->status = Idle;
- bgp_timer_set (peer);
+ BGP_EVENT_FLUSH_ADD (peer, BGP_Stop);
return 0;
}
@@ -2375,14 +2366,6 @@
if (BGP_DEBUG (events, EVENTS))
zlog_debug ("%s [Event] Accepting BGP peer delete", peer->host);
peer_delete (peer);
- /* we've lost track of a reference to ACCEPT_PEER somehow. It doesnt
- * _seem_ to be the 'update realpeer with accept peer' hack, yet it
- * *must* be.. Very very odd, but I give up trying to
- * root cause this - ACCEPT_PEER is a dirty hack, it should be fixed
- * instead, which would make root-causing this a moot point..
- * A hack because of a hack, appropriate.
- */
- peer_unlock (peer); /* god knows what reference... ACCEPT_PEER sucks */
}
return 0;
}
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 2ce2ef4..5dde41d 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -2527,11 +2527,10 @@
{
struct peer *peer = wq->spec.data;
- UNSET_FLAG (peer->sflags, PEER_STATUS_CLEARING);
peer_unlock (peer); /* bgp_clear_node_complete */
/* Tickle FSM to start moving again */
- BGP_EVENT_ADD (peer, BGP_Start);
+ BGP_EVENT_ADD (peer, Clearing_Completed);
}
static void
@@ -2593,9 +2592,10 @@
if (peer->clear_node_queue == NULL)
bgp_clear_node_queue_init (peer);
- /* bgp_fsm.c will not bring CLEARING sessions out of Idle this
- * protects against peers which flap faster than we can we clear,
- * which could lead to:
+ /* bgp_fsm.c keeps sessions in state Clearing, not transitioning to
+ * Idle until it receives a Clearing_Completed event. This protects
+ * against peers which flap faster than we can we clear, which could
+ * lead to:
*
* a) race with routes from the new session being installed before
* clear_route_node visits the node (to delete the route of that
@@ -2604,11 +2604,8 @@
* on the process_main queue. Fast-flapping could cause that queue
* to grow and grow.
*/
- if (!CHECK_FLAG (peer->sflags, PEER_STATUS_CLEARING))
- {
- SET_FLAG (peer->sflags, PEER_STATUS_CLEARING);
- peer_lock (peer); /* bgp_clear_node_complete */
- }
+ if (!peer->clear_node_queue->thread)
+ peer_lock (peer); /* bgp_clear_node_complete */
if (safi != SAFI_MPLS_VPN)
bgp_clear_route_table (peer, afi, safi, NULL, NULL);
@@ -2624,11 +2621,37 @@
bgp_clear_route_table (peer, afi, safi, NULL, rsclient);
}
- /* If no routes were cleared, nothing was added to workqueue, run the
- * completion function now.
+ /* If no routes were cleared, nothing was added to workqueue, the
+ * completion function won't be run by workqueue code - call it here.
+ *
+ * Additionally, there is a presumption in FSM that clearing is only
+ * needed if peer state is Established - peers in pre-Established states
+ * shouldn't have any route-update state associated with them (in or out).
+ *
+ * We still get here from FSM through bgp_stop->clear_route_all in
+ * pre-Established though, so this is a useful sanity check to ensure
+ * the assumption above holds.
+ *
+ * At some future point, this check could be move to the top of the
+ * function, and do a quick early-return when state is
+ * pre-Established, avoiding above list and table scans. Once we're
+ * sure it is safe..
*/
if (!peer->clear_node_queue->thread)
bgp_clear_node_complete (peer->clear_node_queue);
+ else
+ {
+ /* clearing queue scheduled. Normal if in Established state
+ * (and about to transition out of it), but otherwise...
+ */
+ if (peer->status != Established)
+ {
+ plog_err (peer->log, "%s [Error] State %s is not Established,"
+ " but routes were cleared - bug!",
+ peer->host, LOOKUP (bgp_status_msg, peer->status));
+ assert (peer->status == Established);
+ }
+ }
}
void
diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index ec4b6c2..b108164 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -6693,8 +6693,6 @@
vty_out (vty, " Idle (Admin)");
else if (CHECK_FLAG (peer->sflags, PEER_STATUS_PREFIX_OVERFLOW))
vty_out (vty, " Idle (PfxCt)");
- else if (CHECK_FLAG (peer->sflags, PEER_STATUS_CLEARING))
- vty_out (vty, " Idle (Clrng)");
else
vty_out (vty, " %-11s", LOOKUP(bgp_status_msg, peer->status));
}
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 8ed598d..733b33a 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -687,6 +687,15 @@
static inline void
peer_free (struct peer *peer)
{
+ assert (peer->status == Deleted);
+
+ /* this /ought/ to have been done already through bgp_stop earlier,
+ * but just to be sure..
+ */
+ bgp_timer_set (peer);
+ BGP_READ_OFF (peer->t_read);
+ BGP_WRITE_OFF (peer->t_write);
+
if (peer->desc)
XFREE (MTYPE_PEER_DESC, peer->desc);
@@ -704,6 +713,7 @@
if (peer->clear_node_queue)
work_queue_free (peer->clear_node_queue);
+ bgp_sync_delete (peer);
memset (peer, 0, sizeof (struct peer));
XFREE (MTYPE_BGP_PEER, peer);
@@ -714,7 +724,8 @@
peer_lock (struct peer *peer)
{
assert (peer && (peer->lock >= 0));
-
+ assert (peer->status != Deleted);
+
peer->lock++;
return peer;
@@ -761,18 +772,17 @@
struct servent *sp;
/* Allocate new peer. */
- peer = XMALLOC (MTYPE_BGP_PEER, sizeof (struct peer));
- memset (peer, 0, sizeof (struct peer));
+ peer = XCALLOC (MTYPE_BGP_PEER, sizeof (struct peer));
/* Set default value. */
peer->fd = -1;
- peer->lock = 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->weight = 0;
+ peer = peer_lock (peer); /* initial reference */
/* Set default flags. */
for (afi = AFI_IP; afi < AFI_MAX; afi++)
@@ -1139,7 +1149,17 @@
bgp_clear_route_all (peer);
}
-/* Delete peer from confguration. */
+/* Delete peer from confguration.
+ *
+ * The peer is moved to a dead-end "Deleted" neighbour-state, to allow
+ * it to "cool off" and refcounts to hit 0, at which state it is freed.
+ *
+ * This function /should/ take care to be idempotent, to guard against
+ * it being called multiple times through stray events that come in
+ * that happen to result in this function being called again. That
+ * said, getting here for a "Deleted" peer is a bug in the neighbour
+ * FSM.
+ */
int
peer_delete (struct peer *peer)
{
@@ -1149,6 +1169,8 @@
struct bgp *bgp;
struct bgp_filter *filter;
+ assert (peer->status != Deleted);
+
bgp = peer->bgp;
if (CHECK_FLAG (peer->sflags, PEER_STATUS_NSF_WAIT))
@@ -1158,8 +1180,13 @@
relationship. */
if (peer->group)
{
- peer = peer_unlock (peer); /* peer-group reference */
- listnode_delete (peer->group->peer, peer);
+ struct listnode *pn;
+
+ if ((pn = listnode_lookup (peer->group->peer, peer)))
+ {
+ peer = peer_unlock (peer); /* group->peer list reference */
+ list_delete_node (peer->group->peer, pn);
+ }
peer->group = NULL;
}
@@ -1169,29 +1196,25 @@
*/
peer->last_reset = PEER_DOWN_NEIGHBOR_DELETE;
bgp_stop (peer);
- bgp_fsm_change_status (peer, Idle); /* stops all timers */
+ bgp_fsm_change_status (peer, Deleted);
+ bgp_timer_set (peer); /* stops all timers for Deleted */
- /* Stop all timers - should already have been done in bgp_stop */
- 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);
- BGP_TIMER_OFF (peer->t_pmax_restart);
- BGP_TIMER_OFF (peer->t_gr_restart);
- BGP_TIMER_OFF (peer->t_gr_stale);
-
/* Delete from all peer list. */
if (! CHECK_FLAG (peer->sflags, PEER_STATUS_GROUP))
{
- peer_unlock (peer); /* bgp peer list reference */
- listnode_delete (bgp->peer, peer);
+ struct listnode *pn;
- if (peer_rsclient_active (peer))
+ if ((pn = listnode_lookup (bgp->peer, peer)))
+ {
+ peer_unlock (peer); /* bgp peer list reference */
+ list_delete_node (bgp->peer, pn);
+ }
+
+ if (peer_rsclient_active (peer)
+ && (pn = listnode_lookup (bgp->rsclient, peer)))
{
peer_unlock (peer); /* rsclient list reference */
- listnode_delete (bgp->rsclient, peer);
+ list_delete_node (bgp->rsclient, pn);
}
}
@@ -1219,8 +1242,6 @@
sockunion_free (peer->su_remote);
peer->su_local = peer->su_remote = NULL;
- bgp_sync_delete (peer);
-
/* Free filter related memory. */
for (afi = AFI_IP; afi < AFI_MAX; afi++)
for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++)
@@ -1692,7 +1713,7 @@
peer->group = group;
peer->af_group[afi][safi] = 1;
- peer = peer_lock (peer); /* peer-group group->peer reference */
+ peer = peer_lock (peer); /* group->peer list reference */
listnode_add (group->peer, peer);
peer_group2peer_config_copy (group, peer, afi, safi);
@@ -1733,9 +1754,11 @@
{
peer->group = group;
- peer = peer_lock (peer); /* peer-group group->peer reference */
+ peer = peer_lock (peer); /* group->peer list reference */
listnode_add (group->peer, peer);
}
+ else
+ assert (group && peer->group == group);
if (first_member)
{
@@ -1759,13 +1782,16 @@
if (CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_RSERVER_CLIENT))
{
+ struct listnode *pn;
+
/* If it's not configured as RSERVER_CLIENT in any other address
family, without being member of a peer_group, remove it from
list bgp->rsclient.*/
- if (! peer_rsclient_active (peer))
+ if (! peer_rsclient_active (peer)
+ && (pn = listnode_lookup (bgp->rsclient, peer)))
{
peer_unlock (peer); /* peer rsclient reference */
- listnode_delete (bgp->rsclient, peer);
+ list_delete_node (bgp->rsclient, pn);
}
bgp_table_finish (peer->rib[afi][safi]);
@@ -1821,6 +1847,7 @@
if (! peer_group_active (peer))
{
+ assert (listnode_lookup (group->peer, peer));
peer_unlock (peer); /* peer group list reference */
listnode_delete (group->peer, peer);
peer->group = NULL;
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index b8ae30a..8b180a4 100644
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -386,7 +386,6 @@
#define PEER_STATUS_GROUP (1 << 4) /* peer-group conf */
#define PEER_STATUS_NSF_MODE (1 << 5) /* NSF aware peer */
#define PEER_STATUS_NSF_WAIT (1 << 6) /* wait comeback peer */
-#define PEER_STATUS_CLEARING (1 << 7) /* peers table being cleared */
/* Peer status af flags (reset in bgp_stop) */
u_int16_t af_sflags[AFI_MAX][SAFI_MAX];
@@ -662,7 +661,9 @@
#define OpenSent 4
#define OpenConfirm 5
#define Established 6
-#define BGP_STATUS_MAX 7
+#define Clearing 7
+#define Deleted 8
+#define BGP_STATUS_MAX 9
/* BGP finite state machine events. */
#define BGP_Start 1
@@ -678,7 +679,8 @@
#define Receive_KEEPALIVE_message 11
#define Receive_UPDATE_message 12
#define Receive_NOTIFICATION_message 13
-#define BGP_EVENTS_MAX 14
+#define Clearing_Completed 14
+#define BGP_EVENTS_MAX 15
/* BGP timers default value. */
#define BGP_INIT_START_TIMER 5