Change in osmo-msc[master]: fix _gsm48_cc_trans_free(): send MNCC REL.ind on Clear Request

This is merely a historical archive of years 2008-2021, before the migration to mailman3.

A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/gerrit-log@lists.osmocom.org/.

fixeria gerrit-no-reply at lists.osmocom.org
Sat Feb 13 05:03:42 UTC 2021


fixeria has submitted this change. ( https://gerrit.osmocom.org/c/osmo-msc/+/22747 )

Change subject: fix _gsm48_cc_trans_free(): send MNCC REL.ind on Clear Request
......................................................................

fix _gsm48_cc_trans_free(): send MNCC REL.ind on Clear Request

Calling gsm48_cc_tx_release() before mncc_release_ind() has a side
effect: the former may change CC state to GSM_CSTATE_RELEASE_REQ.
This makes the later send MNCC_REL_CNF instead of MNCC_REL_IND, so
if one of the call leg disconnects due to RF failure, the other one
will not be terminated correctly.

Makes both TC_{mo,mt}_call_clear_request TTCN-3 test cases pass.

Change-Id: I3ad4a99757878de3796027325627c87d9a4e93f1
Related: Id16969fe0de04445d1320a96d35cf1d48cc8cf09
Related: SYS#5340
---
M src/libmsc/gsm_04_08_cc.c
M tests/msc_vlr/msc_vlr_test_call.c
M tests/msc_vlr/msc_vlr_test_call.err
3 files changed, 10 insertions(+), 12 deletions(-)

Approvals:
  Jenkins Builder: Verified
  pespin: Looks good to me, but someone else must approve
  laforge: Looks good to me, but someone else must approve
  fixeria: Looks good to me, approved



diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index ed29e84..704e596 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -272,6 +272,13 @@
 
 	/* send release to L4, if callref still exists */
 	if (trans->callref) {
+		/* Send MNCC REL.ind (cause='Resource unavailable') */
+		if (trans->cc.mncc_initiated) {
+			mncc_release_ind(trans->net, trans, trans->callref,
+					 GSM48_CAUSE_LOC_PRN_S_LU,
+					 GSM48_CC_CAUSE_RESOURCE_UNAVAIL);
+		}
+
 		/* FIXME: currently, a CC trans that would not yet be in state GSM_CSTATE_RELEASE_REQ fails to send a
 		 * CC Release to the MS if it gets freed here. Hack it to do so. */
 		if (trans->cc.state != GSM_CSTATE_RELEASE_REQ) {
@@ -280,11 +287,6 @@
 			mncc_set_cause(&rel, GSM48_CAUSE_LOC_PRN_S_LU, GSM48_CC_CAUSE_RESOURCE_UNAVAIL);
 			gsm48_cc_tx_release(trans, &rel);
 		}
-		/* Resource unavailable */
-		if (trans->cc.mncc_initiated)
-			mncc_release_ind(trans->net, trans, trans->callref,
-					 GSM48_CAUSE_LOC_PRN_S_LU,
-					 GSM48_CC_CAUSE_RESOURCE_UNAVAIL);
 		/* 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);
diff --git a/tests/msc_vlr/msc_vlr_test_call.c b/tests/msc_vlr/msc_vlr_test_call.c
index b4e20be..9ab1066 100644
--- a/tests/msc_vlr/msc_vlr_test_call.c
+++ b/tests/msc_vlr/msc_vlr_test_call.c
@@ -457,11 +457,7 @@
 	fake_time_passes(15, 23);
 
 	btw("The call failed, the BSC sends a BSSMAP Clear Request");
-	/* FIXME: in this scenario, we send an MNCC_REL_CNF even though MNCC never asked us to MNCC_REL_REQ.  Legacy
-	 * behavior did get to both MNCC_REL_IND, then an MNCC_REL_REQ from MNCC as well as a final MNCC_REL_CNF, but
-	 * this only worked synchronously, i.e. only with internal MNCC. Instead of mimicking that, we need a proper
-	 * async solution that also works with a PBX. */
-	cc_to_mncc_expect_tx("", MNCC_REL_CNF);
+	cc_to_mncc_expect_tx("", MNCC_REL_IND);
 	dtap_expect_tx("032d0802e1af"); /* CC: Release */
 	expect_iu_release();
 	msc_a_release_cn(msub_msc_a(g_msub));
diff --git a/tests/msc_vlr/msc_vlr_test_call.err b/tests/msc_vlr/msc_vlr_test_call.err
index 1bcc489..e8e3880 100644
--- a/tests/msc_vlr/msc_vlr_test_call.err
+++ b/tests/msc_vlr/msc_vlr_test_call.err
@@ -1302,6 +1302,8 @@
 DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 4 (attached,CC,active-conn,msc_a_fsm_releasing_onenter)
 DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) Freeing transaction
 DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T301
+DMNCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_REL_IND
+  MSC --> MNCC: callref 0x423: MNCC_REL_IND
 DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T308 with 10 seconds
 DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state CALL_RECEIVED -> RELEASE_REQ
 DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
@@ -1309,8 +1311,6 @@
 - DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 032d0802e1af
 - DTAP matches expected message
 DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
-DMNCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_REL_CNF
-  MSC --> MNCC: callref 0x423: MNCC_REL_CNF
 DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T308
 DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state RELEASE_REQ -> NULL
 DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - CC: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)

-- 
To view, visit https://gerrit.osmocom.org/c/osmo-msc/+/22747
To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings

Gerrit-Project: osmo-msc
Gerrit-Branch: master
Gerrit-Change-Id: I3ad4a99757878de3796027325627c87d9a4e93f1
Gerrit-Change-Number: 22747
Gerrit-PatchSet: 3
Gerrit-Owner: fixeria <vyanitskiy at sysmocom.de>
Gerrit-Assignee: neels <nhofmeyr at sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria <vyanitskiy at sysmocom.de>
Gerrit-Reviewer: laforge <laforge at osmocom.org>
Gerrit-Reviewer: neels <nhofmeyr at sysmocom.de>
Gerrit-Reviewer: pespin <pespin at sysmocom.de>
Gerrit-MessageType: merged
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osmocom.org/pipermail/gerrit-log/attachments/20210213/3eb23aaa/attachment.htm>


More information about the gerrit-log mailing list