fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bsc/+/42591?usp=email )

Change subject: lchan_fsm: ignore late lchan_rtp_fsm events ......................................................................

lchan_fsm: ignore late lchan_rtp_fsm events

The lchan_rtp_fsm is a child FSM that manages the MGW/RTP endpoint. When the parent lchan_fsm transitions away before the child has finished its work (e.g. a CRCX timeout or a DLCX completing after the lchan is already idle), the child can still deliver LCHAN_EV_RTP_RELEASED or LCHAN_EV_RTP_ERROR to the parent.

Currently these late events are not in the in_event_mask of every state that can be reached with the child still running:

* LCHAN_ST_UNUSED: entered from WAIT_AFTER_ERROR after the error timer fires, while a DLCX triggered at error time may still be in flight. * LCHAN_ST_WAIT_AFTER_ERROR: already handles LCHAN_EV_RTP_RELEASED but misses LCHAN_EV_RTP_ERROR (e.g. CRCX timeout arriving after the NACK was handled).

Add the missing events to both states' in_event_mask and provide a no-op handler in lchan_fsm_unused() so that the assert is not hit.

Change-Id: Ie6333bd941e4e5a6ddf0e3f113b8764e8bc2bbc0 --- M src/osmo-bsc/lchan_fsm.c 1 file changed, 8 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/91/42591/1

diff --git a/src/osmo-bsc/lchan_fsm.c b/src/osmo-bsc/lchan_fsm.c index 55875f0..524d66e 100644 --- a/src/osmo-bsc/lchan_fsm.c +++ b/src/osmo-bsc/lchan_fsm.c @@ -736,6 +736,11 @@ lchan_fsm_state_chg(LCHAN_ST_WAIT_TS_READY); break;

+ case LCHAN_EV_RTP_RELEASED: + case LCHAN_EV_RTP_ERROR: + /* Ignore late lchan_rtp_fsm events arriving after the lchan is back to UNUSED. */ + break; + default: OSMO_ASSERT(false); } @@ -1710,6 +1715,8 @@ .action = lchan_fsm_unused, .in_event_mask = 0 | S(LCHAN_EV_ACTIVATE) + | S(LCHAN_EV_RTP_RELEASED) /* ignore late lchan_rtp_fsm release events */ + | S(LCHAN_EV_RTP_ERROR) /* ignore late lchan_rtp_fsm error events */ , .out_state_mask = 0 | S(LCHAN_ST_WAIT_TS_READY) @@ -1869,6 +1876,7 @@ .onenter = lchan_fsm_wait_after_error_onenter, .in_event_mask = 0 | S(LCHAN_EV_RTP_RELEASED) /* ignore late lchan_rtp_fsm release events */ + | S(LCHAN_EV_RTP_ERROR) /* ignore late lchan_rtp_fsm error events */ , .out_state_mask = 0 | S(LCHAN_ST_UNUSED)