diff options
authorNeels Hofmeyr <neels@hofmeyr.de>2018-04-09 23:29:14 +0200
committerHarald Welte <laforge@gnumonks.org>2018-04-11 21:39:44 +0000
commitdc2514b22062af04354c0331f0f5819051c3fdee (patch)
parent79beccd93a27796a2ca9be201a5b9cf3695fbf5c (diff)
CC: intentionally release T308 on BSSMAP Clear Request from BSC
So far we hit a running T308 during CC release when caused by a BSSMAP Clear Request, and we loudly log that as error. However, now I understand that T308 is a direct cause of the dispatch of a REL IND towards MNCC, which is used to indicate teardown to MNCC. So during _gsm48_cc_trans_free(), we first clear all timers, then invoke mncc_release_ind() which starts another timer (useful for graceful CC Release, but in this code path the intention is immediate release). Simply immediately cancel the timer again and release the conn. A separate question is whether a BSSMAP Clear Request should be less aggressive in releasing the connections; i.e. instead of calling trans_free() all around, to rather ask each transaction to "please stop soon", somehow. Related: OS#3062 Change-Id: I231fdb574a086a206321148474cbdc7ca9cf39f0
3 files changed, 4 insertions, 10 deletions
diff --git a/src/libmsc/gsm_04_08.c b/src/libmsc/gsm_04_08.c
index e5ddb44d4..f29c0b68e 100644
--- a/src/libmsc/gsm_04_08.c
+++ b/src/libmsc/gsm_04_08.c
@@ -1422,6 +1422,9 @@ void _gsm48_cc_trans_free(struct gsm_trans *trans)
mncc_release_ind(trans->net, trans, trans->callref,
+ /* This is a final freeing of the transaction. The MNCC release may have triggered the
+ * T308 release timer, but we don't have the luxury of graceful CC Release here. */
+ gsm48_stop_cc_timer(trans);
if (trans->cc.state != GSM_CSTATE_NULL)
new_cc_state(trans, GSM_CSTATE_NULL);
diff --git a/src/libmsc/transaction.c b/src/libmsc/transaction.c
index 66b929afa..147099ed7 100644
--- a/src/libmsc/transaction.c
+++ b/src/libmsc/transaction.c
@@ -122,15 +122,6 @@ void trans_free(struct gsm_trans *trans)
switch (trans->protocol) {
case GSM48_PDISC_CC:
- if (osmo_timer_pending(&trans->cc.timer)) {
- "%s Timer 0x%x is still running while discarding transaction"
- " -- this is a bug: we were still expecting a response but"
- " are freeing the transaction anyway\n",
- vlr_subscr_name(trans->conn->vsub), trans->cc.Tcurrent);
- osmo_timer_del(&trans->cc.timer);
- trans->cc.Tcurrent = 0;
- }
conn_usage_token = MSC_CONN_USE_TRANS_CC;
diff --git a/tests/msc_vlr/msc_vlr_test_call.err b/tests/msc_vlr/msc_vlr_test_call.err
index 6142464e9..1b8002b16 100644
--- a/tests/msc_vlr/msc_vlr_test_call.err
+++ b/tests/msc_vlr/msc_vlr_test_call.err
@@ -1085,8 +1085,8 @@ DMSC msc_tx 2 bytes to MSISDN:42342 via RAN_UTRAN_IU
DMNCC transmit message MNCC_REL_CNF
MSC --> MNCC: callref 0x423: MNCC_REL_CNF
+DCC stopping pending timer T308
DCC (ti 00 sub MSISDN:42342) new state RELEASE_REQ -> NULL
-DCC MSISDN:42342 Timer 0x308 is still running while discarding transaction -- this is a bug: we were still expecting a response but are freeing the transaction anyway
DREF VLR subscr MSISDN:42342 usage decreases to: 2
DREF MSISDN:42342: MSC conn use - trans_cc == 1 (0x4)
- Iu Release --RAN_UTRAN_IU--> MS