bgpd: stricter packet handling in OpenSent
Keepalives and updates are not expected in OpenSent, prior to receiving
the peer's open message. Terminate the session with the proper
notification.
From: Leonid Rosenboim <lrosenbo@wrs.com>
[split off FSM changes, some reordering & cleanup. read handling needs
to be separately addressed]
Signed-off-by: David Lamparter <equinox@diac24.net>
diff --git a/bgpd/bgp_fsm.c b/bgpd/bgp_fsm.c
index d920045..fba9427 100644
--- a/bgpd/bgp_fsm.c
+++ b/bgpd/bgp_fsm.c
@@ -592,6 +592,32 @@
return 0;
}
+
+/* something went wrong, send notify and tear down */
+static int
+bgp_stop_with_notify (struct peer *peer, u_char code, u_char sub_code)
+{
+ /* Send notify to remote peer */
+ bgp_notify_send (peer, code, sub_code);
+
+ /* Sweep if it is temporary peer. */
+ if (CHECK_FLAG (peer->sflags, PEER_STATUS_ACCEPT_PEER))
+ {
+ zlog_info ("%s [Event] Accepting BGP peer is deleted", peer->host);
+ peer_delete (peer);
+ return -1;
+ }
+
+ /* Clear start timer value to default. */
+ peer->v_start = BGP_INIT_START_TIMER;
+
+ /* bgp_stop needs to be invoked while in Established state */
+ bgp_stop(peer);
+
+ return 0;
+}
+
+
/* TCP connection open. Next we send open message to remote peer. And
add read thread for reading open message. */
static int
@@ -740,29 +766,26 @@
return 0;
}
+/* FSM error, unexpected event. This is error of BGP connection. So cut the
+ peer and change to Idle status. */
+static int
+bgp_fsm_event_error (struct peer *peer)
+{
+ plog_err (peer->log, "%s [FSM] unexpected packet received in state %s",
+ peer->host, LOOKUP (bgp_status_msg, peer->status));
+
+ return bgp_stop_with_notify (peer, BGP_NOTIFY_FSM_ERR, 0);
+}
+
/* Hold timer expire. This is error of BGP connection. So cut the
peer and change to Idle status. */
static int
bgp_fsm_holdtime_expire (struct peer *peer)
{
if (BGP_DEBUG (fsm, FSM))
- zlog (peer->log, LOG_DEBUG, "%s [FSM] Hold timer expire", peer->host);
+ plog_debug (peer->log, "%s [FSM] Hold timer expire", peer->host);
- /* Send notify to remote peer. */
- bgp_notify_send (peer, BGP_NOTIFY_HOLD_ERR, 0);
-
- /* Sweep if it is temporary peer. */
- if (CHECK_FLAG (peer->sflags, PEER_STATUS_ACCEPT_PEER))
- {
- zlog_info ("%s [Event] Accepting BGP peer is deleted", peer->host);
- peer_delete (peer);
- return -1;
- }
-
- /* bgp_stop needs to be invoked while in Established state */
- bgp_stop(peer);
-
- return 0;
+ return bgp_stop_with_notify (peer, BGP_NOTIFY_HOLD_ERR, 0);
}
/* Status goes to Established. Send keepalive packet then make first
@@ -977,8 +1000,8 @@
{bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
{bgp_ignore, Idle}, /* KeepAlive_timer_expired */
{bgp_fsm_open, OpenConfirm}, /* Receive_OPEN_message */
- {bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
- {bgp_ignore, Idle}, /* Receive_UPDATE_message */
+ {bgp_fsm_event_error, Idle}, /* Receive_KEEPALIVE_message */
+ {bgp_fsm_event_error, Idle}, /* Receive_UPDATE_message */
{bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
{bgp_ignore, Idle}, /* Clearing_Completed */
},