From 21e8caa2935e1ee29b24b8d8b110ca0d4196cecf Mon Sep 17 00:00:00 2001 From: Quentin Young Date: Thu, 11 Feb 2021 18:54:27 -0500 Subject: bgpd: send correct BMP down message when nht fails When sending BMP messages for a status change event for a peer whose NHT has failed, we were sending a Peer Down Reason Code of 1 (Local system closed, NOTIFICATION follows) with no NOTIFICAION PDU (because there was none). This is wrong. Also, the reason code of 1 is semantically off, it should be 2 (Local system closed, FSM event follows). This patch: - adds definitions of all BGP FSM event codes per RFC4271 - changes the BMP reason code emitted when a peer changes state due to NHT failure to 2 and encodes FSM event 18 (TcpConnectionFails) - changes the catch-all case where we have not yet implemented the appropriate BMP response to indicate reason code 2 with FSM event 0 (no relevant Event code is defined). These changes ought to prevent the BMP session from being torn down due to an improperly formatted message. Signed-off-by: Quentin Young --- bgpd/bgp_bmp.c | 15 ++++++++++++--- bgpd/bgp_bmp.h | 2 ++ bgpd/bgpd.h | 42 +++++++++++++++++++++++++++++++++++++++++- 3 files changed, 55 insertions(+), 4 deletions(-) (limited to 'bgpd') diff --git a/bgpd/bgp_bmp.c b/bgpd/bgp_bmp.c index 82e27884c..c93713668 100644 --- a/bgpd/bgp_bmp.c +++ b/bgpd/bgp_bmp.c @@ -434,10 +434,19 @@ static struct stream *bmp_peerstate(struct peer *peer, bool down) case PEER_DOWN_CLOSE_SESSION: type = BMP_PEERDOWN_REMOTE_CLOSE; break; + case PEER_DOWN_WAITING_NHT: + type = BMP_PEERDOWN_LOCAL_FSM; + stream_putw(s, BGP_FSM_TcpConnectionFails); + break; + /* + * TODO: Map remaining PEER_DOWN_* reasons to RFC event codes. + * TODO: Implement BMP_PEERDOWN_LOCAL_NOTIFY. + * + * See RFC7854 ss. 4.9 + */ default: - type = BMP_PEERDOWN_LOCAL_NOTIFY; - stream_put(s, peer->last_reset_cause, - peer->last_reset_cause_size); + type = BMP_PEERDOWN_LOCAL_FSM; + stream_putw(s, BMP_PEER_DOWN_NO_RELEVANT_EVENT_CODE); break; } stream_putc_at(s, type_pos, type); diff --git a/bgpd/bgp_bmp.h b/bgpd/bgp_bmp.h index d6b22d0cb..2c3ba570e 100644 --- a/bgpd/bgp_bmp.h +++ b/bgpd/bgp_bmp.h @@ -269,6 +269,8 @@ struct bmp_bgp_peer { /* per struct bgp * data */ PREDECL_HASH(bmp_bgph) +#define BMP_PEER_DOWN_NO_RELEVANT_EVENT_CODE 0x00 + struct bmp_bgp { struct bmp_bgph_item bbi; diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h index 9f453bf1e..7a8f99163 100644 --- a/bgpd/bgpd.h +++ b/bgpd/bgpd.h @@ -921,7 +921,47 @@ struct bgp_peer_gr { bgp_peer_gr_action_ptr action_fun; }; -/* BGP finite state machine events. */ +/* + * BGP FSM event codes, per RFC 4271 ss. 8.1 + */ +enum bgp_fsm_rfc_codes { + BGP_FSM_ManualStart = 1, + BGP_FSM_ManualStop = 2, + BGP_FSM_AutomaticStart = 3, + BGP_FSM_ManualStart_with_PassiveTcpEstablishment = 4, + BGP_FSM_AutomaticStart_with_PassiveTcpEstablishment = 5, + BGP_FSM_AutomaticStart_with_DampPeerOscillations = 6, + BGP_FSM_AutomaticStart_with_DampPeerOscillations_and_PassiveTcpEstablishment = + 7, + BGP_FSM_AutomaticStop = 8, + BGP_FSM_ConnectRetryTimer_Expires = 9, + BGP_FSM_HoldTimer_Expires = 10, + BGP_FSM_KeepaliveTimer_Expires = 11, + BGP_FSM_DelayOpenTimer_Expires = 12, + BGP_FSM_IdleHoldTimer_Expires = 13, + BGP_FSM_TcpConnection_Valid = 14, + BGP_FSM_Tcp_CR_Invalid = 15, + BGP_FSM_Tcp_CR_Acked = 16, + BGP_FSM_TcpConnectionConfirmed = 17, + BGP_FSM_TcpConnectionFails = 18, + BGP_FSM_BGPOpen = 19, + BGP_FSM_BGPOpen_with_DelayOpenTimer_running = 20, + BGP_FSM_BGPHeaderErr = 21, + BGP_FSM_BGPOpenMsgErr = 22, + BGP_FSM_OpenCollisionDump = 23, + BGP_FSM_NotifMsgVerErr = 24, + BGP_FSM_NotifMsg = 25, + BGP_FSM_KeepAliveMsg = 26, + BGP_FSM_UpdateMsg = 27, + BGP_FSM_UpdateMsgErr = 28 +}; + +/* + * BGP finite state machine events + * + * Note: these do not correspond to RFC-defined event codes. Those are + * defined elsewhere. + */ enum bgp_fsm_events { BGP_Start = 1, BGP_Stop, -- cgit v1.2.3