diff options
Diffstat (limited to 'bgpd/bgp_fsm.c')
| -rw-r--r-- | bgpd/bgp_fsm.c | 134 |
1 files changed, 104 insertions, 30 deletions
diff --git a/bgpd/bgp_fsm.c b/bgpd/bgp_fsm.c index d51ab09b..87e13ecb 100644 --- a/bgpd/bgp_fsm.c +++ b/bgpd/bgp_fsm.c @@ -390,7 +390,7 @@ static inline void bgp_hold_timer_recharge(bgp_connection connection) { if (connection->hold_timer_interval != 0) - qtimer_set_interval(&connection->hold_timer, + qtimer_set_interval(connection->hold_timer, QTIME(connection->hold_timer_interval), NULL) ; } ; @@ -634,11 +634,11 @@ bgp_fsm_io_error(bgp_connection connection, int err) if (err == 0) plog_debug(connection->log, "%s [Event] BGP connection closed fd %d", - connection->host, qps_file_fd(&connection->qf)) ; + connection->host, qps_file_fd(connection->qf)) ; else plog_debug(connection->log, "%s [Event] BGP connection closed fd %d (%s)", - connection->host, qps_file_fd(&connection->qf), + connection->host, qps_file_fd(connection->qf), safe_strerror(err)) ; } ; @@ -755,6 +755,7 @@ static bgp_fsm_action(bgp_fsm_enter) ; static bgp_fsm_action(bgp_fsm_stop) ; static bgp_fsm_action(bgp_fsm_invalid) ; static bgp_fsm_action(bgp_fsm_start) ; +static bgp_fsm_action(bgp_fsm_half_open) ; static bgp_fsm_action(bgp_fsm_connect) ; static bgp_fsm_action(bgp_fsm_accept) ; static bgp_fsm_action(bgp_fsm_send_open) ; @@ -827,7 +828,14 @@ static bgp_fsm_action(bgp_fsm_exit) ; * * raised when a connect() connection succeeds * - * b. secondary connection: in sActive state (-> OpenSent) + * b. secondary connection: in sIdle state (stay sIdle) + * + * raised when an accept() connection is accepted. + * + * The connection is not refused, but it is ignored until the + * IdleHoldTimer expires. + * + * c. secondary connection: in sActive state (-> OpenSent) * * raised when an accept() connection is accepted. * @@ -1082,12 +1090,19 @@ bgp_fsm[bgp_fsm_last_state + 1][bgp_fsm_last_event + 1] = * * * eBGP_Stop -- for whatever reason * + * * eTCP_connection_open -- generated if connection is accepted + * + * This set the connection "half_open", but stays in sIdle until + * the IdleHoldTimer expires. This avoids rejecting inbound + * connections, but also enforces the IdleHoldTimer if the other end + * is being vexatious. + * * All other events (other than null) are invalid (should not happen). */ {bgp_fsm_null, bgp_fsm_sIdle}, /* null event */ {bgp_fsm_start, bgp_fsm_sConnect}, /* BGP_Start */ {bgp_fsm_stop, bgp_fsm_sIdle}, /* BGP_Stop */ - {bgp_fsm_invalid, bgp_fsm_sStopping}, /* TCP_connection_open */ + {bgp_fsm_half_open, bgp_fsm_sIdle}, /* TCP_connection_open */ {bgp_fsm_invalid, bgp_fsm_sStopping}, /* TCP_connection_closed */ {bgp_fsm_invalid, bgp_fsm_sStopping}, /* TCP_connection_open_failed */ {bgp_fsm_invalid, bgp_fsm_sStopping}, /* TCP_fatal_error */ @@ -1397,9 +1412,6 @@ bgp_fsm_state_change(bgp_connection connection, bgp_fsm_state_t new_state) ; /*------------------------------------------------------------------------------ * Signal event to FSM for the given connection. - * - * - * */ static void bgp_fsm_event(bgp_connection connection, bgp_fsm_event_t event) @@ -1535,7 +1547,10 @@ static bgp_fsm_action(bgp_fsm_null) static bgp_fsm_action(bgp_fsm_enter) { if (connection->ordinal == bgp_connection_secondary) - bgp_prepare_to_accept(connection) ; + { + bgp_prepare_to_accept(connection) ; + bgp_connection_enable_accept(connection) ; + } ; return next_state ; } ; @@ -1582,22 +1597,72 @@ static bgp_fsm_action(bgp_fsm_invalid) } ; /*------------------------------------------------------------------------------ + * Half open a BGP Connection + * + * Used during sIdle when a connection is made before the IdleHoldTimer + * expires. + * + * Expected only for the secondary connection. + * + * Sets the connection half_open, and remains in sIdle. + * + * NB: requires the session LOCKED + */ +static bgp_fsm_action(bgp_fsm_half_open) +{ + assert( (connection->ordinal == bgp_connection_secondary) + && !connection->half_open ) ; + + connection->half_open = 1 ; + + return next_state ; +} ; + +/*------------------------------------------------------------------------------ * Start up BGP Connection * * Used on exit from sIdle to sConnect or sActive -- when the IdleHoldTimer * expires. * - * Enters either sConnect or sActive, depending on primary/secondary. + * If not half open: + * + * Enters either sConnect or sActive, depending on primary/secondary. + * + * Throws a session_eStart exception so the Routing Engine gets to see this, + * and a follow-on fsm_eBGP_Start event to kick the connect() or accept() + * into life. * - * Throws a session_eStart exception so the Routing Engine gets to see this, - * and a follow-on fsm_eBGP_Start event to kick the connect() or accept() into - * life. + * If is half open: + * + * Must be secondary. Enters sActive. + * + * Throws a session_eStart exception so the Routing Engine gets to see this, + * and a follow-on bgp_fsm_eTCP_connection_open event to kick sActive into + * processing the already open connection. * * NB: requires the session LOCKED */ static bgp_fsm_action(bgp_fsm_start) { - bgp_fsm_throw(connection, bgp_session_eStart, NULL, 0, bgp_fsm_eBGP_Start) ; + bgp_fsm_event_t fsm_event ; + + if (!connection->half_open) + /* Straightforward -- set eBGP_Start follow-on event */ + fsm_event = bgp_fsm_eBGP_Start ; + else + { + /* Is half open -- so set a eTCP_connection_open follow-on event, then + * change to sActive where the event will be collected. + */ + assert(connection->ordinal == bgp_connection_secondary) ; + + connection->half_open = 0 ; + + fsm_event = bgp_fsm_eTCP_connection_open ; + } ; + + bgp_fsm_throw(connection, bgp_session_eStart, NULL, 0, fsm_event) ; + return (connection->ordinal == bgp_connection_primary) ? bgp_fsm_sConnect : bgp_fsm_sActive ; } ; @@ -1636,6 +1701,7 @@ static bgp_fsm_action(bgp_fsm_accept) return next_state ; } ; + /*------------------------------------------------------------------------------ * TCP connection open has come up -- connect() or accept() * @@ -1833,7 +1899,7 @@ static bgp_fsm_action(bgp_fsm_recv_open) } ; /* All is well: send a KEEPALIVE message to acknowledge the OPEN */ - bgp_msg_send_keepalive(connection) ; + bgp_msg_send_keepalive(connection, 1) ; /* Transition to OpenConfirm state */ return next_state ; @@ -1895,7 +1961,7 @@ static bgp_fsm_action(bgp_fsm_sent_nom) */ static bgp_fsm_action(bgp_fsm_send_kal) { - bgp_msg_send_keepalive(connection) ; + bgp_msg_send_keepalive(connection, 0) ; return next_state ; } ; @@ -2060,7 +2126,7 @@ bgp_fsm_catch(bgp_connection connection, bgp_fsm_state_t next_state) next_state = connection->state ; /* Make sure that cannot pop out a Keepalive ! */ - qtimer_unset(&connection->keepalive_timer) ; + qtimer_unset(connection->keepalive_timer) ; /* Write the message */ bgp_msg_write_notification(connection, send_notification) ; @@ -2207,7 +2273,7 @@ bgp_timer_set(bgp_connection connection, qtimer timer, unsigned secs, static void bgp_hold_timer_set(bgp_connection connection, unsigned secs) { - bgp_timer_set(connection, &connection->hold_timer, secs, no_jitter, + bgp_timer_set(connection, connection->hold_timer, secs, no_jitter, bgp_hold_timer_action) ; } ; @@ -2248,7 +2314,8 @@ bgp_fsm_state_change(bgp_connection connection, bgp_fsm_state_t new_state) * When entering sIdle from anything other than Initial state, and not * falling into a coma, extend the IdleHoldTimer. * - * In sIdle state refuses connections. + * In sIdle state doesn't refuse connections (unless comatose), but won't + * act on them until the IdleHoldTimer expires. */ case bgp_fsm_sIdle: interval = session->idle_hold_timer_interval ; @@ -2277,21 +2344,28 @@ bgp_fsm_state_change(bgp_connection connection, bgp_fsm_state_t new_state) session->idle_hold_timer_interval = interval ; + if (connection->ordinal == bgp_connection_secondary) + bgp_connection_enable_accept(connection) ; + /* if sibling is comatose, set time for it to come round */ if ((sibling != NULL) && (sibling->comatose)) { - connection->comatose = 0 ; /* no longer comatose */ - bgp_timer_set(sibling, &sibling->hold_timer, interval, + sibling->comatose = 0 ; /* no longer comatose */ + + if (sibling->ordinal == bgp_connection_secondary) + bgp_connection_enable_accept(sibling) ; + + bgp_timer_set(sibling, sibling->hold_timer, interval, with_jitter, bgp_idle_hold_timer_action) ; } ; } ; } ; - bgp_timer_set(connection, &connection->hold_timer, interval, + bgp_timer_set(connection, connection->hold_timer, interval, with_jitter, bgp_idle_hold_timer_action) ; - qtimer_unset(&connection->keepalive_timer) ; + qtimer_unset(connection->keepalive_timer) ; break; @@ -2304,10 +2378,10 @@ bgp_fsm_state_change(bgp_connection connection, bgp_fsm_state_t new_state) */ case bgp_fsm_sConnect: case bgp_fsm_sActive: - bgp_timer_set(connection, &connection->hold_timer, + bgp_timer_set(connection, connection->hold_timer, session->connect_retry_timer_interval, with_jitter, bgp_connect_retry_timer_action) ; - qtimer_unset(&connection->keepalive_timer) ; + qtimer_unset(connection->keepalive_timer) ; break; /* In sOpenSent state is waiting for an OPEN from the other end, before @@ -2317,7 +2391,7 @@ bgp_fsm_state_change(bgp_connection connection, bgp_fsm_state_t new_state) */ case bgp_fsm_sOpenSent: bgp_hold_timer_set(connection, session->open_hold_timer_interval) ; - qtimer_unset(&connection->keepalive_timer) ; + qtimer_unset(connection->keepalive_timer) ; break; /* In sOpenConfirm state is waiting for an "ack" before proceeding to @@ -2336,7 +2410,7 @@ bgp_fsm_state_change(bgp_connection connection, bgp_fsm_state_t new_state) * value will also be zero, and this will unset both timers. */ case bgp_fsm_sOpenConfirm: - bgp_timer_set(connection, &connection->keepalive_timer, + bgp_timer_set(connection, connection->keepalive_timer, connection->keepalive_timer_interval, with_jitter, bgp_keepalive_timer_action) ; case bgp_fsm_sEstablished: @@ -2349,7 +2423,7 @@ bgp_fsm_state_change(bgp_connection connection, bgp_fsm_state_t new_state) * or for the "courtesy" time to expire. */ case bgp_fsm_sStopping: - qtimer_unset(&connection->keepalive_timer) ; + qtimer_unset(connection->keepalive_timer) ; break ; @@ -2393,7 +2467,7 @@ bgp_connect_retry_timer_action(qtimer qtr, void* timer_info, qtime_mono_t when) BGP_FSM_DEBUG(connection, "Timer (connect timer expire)") ; - bgp_timer_set(connection, &connection->hold_timer, + bgp_timer_set(connection, connection->hold_timer, connection->session->connect_retry_timer_interval, with_jitter, NULL) ; bgp_fsm_event(connection, bgp_fsm_eConnectRetry_timer_expired) ; @@ -2427,7 +2501,7 @@ bgp_keepalive_timer_action(qtimer qtr, void* timer_info, qtime_mono_t when) BGP_FSM_DEBUG(connection, "Timer (keepalive timer expire)") ; - bgp_timer_set(connection, &connection->keepalive_timer, + bgp_timer_set(connection, connection->keepalive_timer, connection->session->keepalive_timer_interval, with_jitter, NULL) ; |