lchan_fsm: safer 'concluded' flag
The flag lchan->activate.concluded prevents entering the
lchan_on_fully_established()/lchan_on_activation_failure() more than once. So
far it was checked by callers, instead place in the functions themselves.
There is a potential functional change here, since during lchan_fail(), the
concluded flag was set only after entering lchan_on_activation_failure(). Now
it is already set at the start and prevents multiple re-entry beyond doubt.
This patch is not a result of an actual observed faulty behavior, just from
reading the code and seeing the slight loophole.
Change-Id: I0c906438b05442d66255203eb816453b7193a6d8
diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h
index b827d0a..d6e8954 100644
--- a/include/osmocom/bsc/gsm_data.h
+++ b/include/osmocom/bsc/gsm_data.h
@@ -505,7 +505,10 @@
struct {
enum lchan_activate_mode activ_for;
bool activ_ack; /*< true as soon as RSL Chan Activ Ack is received */
- bool concluded; /*< true as soon as LCHAN_ST_ESTABLISHED is reached */
+ /*! This flag ensures that when an lchan activation has succeeded, and we have already
+ * sent ACKs like Immediate Assignment or BSSMAP Assignment Complete, and if other errors
+ * occur later, e.g. during release, that we don't send a NACK out of context. */
+ bool concluded;
bool requires_voice_stream;
bool wait_before_switching_rtp; /*< true = requires LCHAN_EV_READY_TO_SWITCH_RTP */
uint16_t msc_assigned_cic;