never page for TMSI with 'no assign-tmsi'neels/tmsi_or_not

With 'no assign-tmsi', regard any TMSI as invalidated at the end of a
Location Updating procedure. Hence, avoid paging by TMSI.

When 'no assign-tmsi' is set, osmo-msc does not actively assign a new
TMSI at the end of the Location Updating. However, it stores any TMSI
identity that the MS sends in a Location Updating Request. So far, this
caused osmo-msc to use the TMSI that the MS had sent in subsequent
Paging, which goes unanswered by the MS.

(After the long standing evil twin problem regarding TMSI MI has been
fixed in recent Ifdabe0b65bffafbf7b8e5cc10e2d225d1ed1cecd, there is no
longer an evil twin risked by clearing out a TMSI.)

Related: SYS#6860 OS#4721
Change-Id: I583682d1a35a70b008d7bb2d89ba7c3109a60b21

2 files changed, 15 insertions, 11 deletions

diff --git a/src/libvlr/vlr_lu_fsm.c b/src/libvlr/vlr_lu_fsm.c
index 7500c8622..5d8f78bc2 100644
--- a/src/libvlr/vlr_lu_fsm.c
+++ b/src/libvlr/vlr_lu_fsm.c
@@ -469,6 +469,8 @@ static void lu_compl_vlr_wait_subscr_pres(struct osmo_fsm_inst *fi,
 		lu_compl_vlr_new_tmsi(fi);
 		return;
 	}
+	/* else, any previously used TMSI is now invalid. */
+	vsub->tmsi = GSM_RESERVED_TMSI;
 
 	/* Location Updating Accept */
 	vlr->ops.tx_lu_acc(lcvp->msc_conn_ref, GSM_RESERVED_TMSI);
@@ -514,6 +516,8 @@ static void lu_compl_vlr_wait_imei(struct osmo_fsm_inst *fi, uint32_t event,
 		/* Wait for TMSI ack */
 		return;
 	}
+	/* else, any previously used TMSI is now invalid. */
+	vsub->tmsi = GSM_RESERVED_TMSI;
 
 	/* No TMSI needed, accept now. */
 	vlr->ops.tx_lu_acc(lcvp->msc_conn_ref, GSM_RESERVED_TMSI);
diff --git a/tests/msc_vlr/msc_vlr_test_rest.err b/tests/msc_vlr/msc_vlr_test_rest.err
index fae302f99..3a6442e21 100644
--- a/tests/msc_vlr/msc_vlr_test_rest.err
+++ b/tests/msc_vlr/msc_vlr_test_rest.err
@@ -527,7 +527,7 @@ DVLR lu_compl_vlr_fsm(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:
 DVLR lu_compl_vlr_fsm(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){LU_COMPL_VLR_S_INIT}: state_chg to LU_COMPL_VLR_S_WAIT_SUB_PRES
 DVLR lu_compl_vlr_fsm(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: Received Event LU_COMPL_VLR_E_SUB_PRES_COMPL
 - sending LU Accept for IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU
-DREF VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 + attached: now used by 3 (active-conn,vlr_gsup_rx,attached)
+DREF VLR subscr IMSI-901700000004620:MSISDN-46071 + attached: now used by 3 (active-conn,vlr_gsup_rx,attached)
 DVLR lu_compl_vlr_fsm(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_DONE
 DVLR vlr_lu_fsm(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS
 DVLR lu_compl_vlr_fsm(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){LU_COMPL_VLR_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: upd_hlr_vlr_fsm(TMSI-0x23422342:GERAN-A:LU))
@@ -540,15 +540,15 @@ DREF msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_S
 DMSC msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_UNUSED
 DMSC msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_RELEASING
 DBSSAP msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
-DREF VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 + msc_a_fsm_releasing_onenter: now used by 4 (active-conn,vlr_gsup_rx,attached,msc_a_fsm_releasing_onenter)
-DREF VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 + vlr_subscr_cancel_attach_fsm: now used by 5 (active-conn,vlr_gsup_rx,attached,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
-DREF VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 - vlr_subscr_cancel_attach_fsm: now used by 4 (active-conn,vlr_gsup_rx,attached,msc_a_fsm_releasing_onenter)
+DREF VLR subscr IMSI-901700000004620:MSISDN-46071 + msc_a_fsm_releasing_onenter: now used by 4 (active-conn,vlr_gsup_rx,attached,msc_a_fsm_releasing_onenter)
+DREF VLR subscr IMSI-901700000004620:MSISDN-46071 + vlr_subscr_cancel_attach_fsm: now used by 5 (active-conn,vlr_gsup_rx,attached,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
+DREF VLR subscr IMSI-901700000004620:MSISDN-46071 - vlr_subscr_cancel_attach_fsm: now used by 4 (active-conn,vlr_gsup_rx,attached,msc_a_fsm_releasing_onenter)
 DREF msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
 DMSC msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on GERAN-A
 DMSC dummy_msc_i(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
-DREF VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 - msc_a_fsm_releasing_onenter: now used by 3 (active-conn,vlr_gsup_rx,attached)
+DREF VLR subscr IMSI-901700000004620:MSISDN-46071 - msc_a_fsm_releasing_onenter: now used by 3 (active-conn,vlr_gsup_rx,attached)
 DVLR upd_hlr_vlr_fsm(TMSI-0x23422342:GERAN-A:LU){UPD_HLR_VLR_S_DONE}: Deallocated, including all deferred deallocations
-DREF VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 - vlr_gsup_rx: now used by 2 (active-conn,attached)
+DREF VLR subscr IMSI-901700000004620:MSISDN-46071 - vlr_gsup_rx: now used by 2 (active-conn,attached)
 <-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: vlr_gsupc_read_cb() returns 0
   bssap_clear_sent == 1
 - LU was successful, and the conn has already been closed
@@ -566,19 +566,19 @@ DVLR vlr_lu_fsm(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){VL
 DMSC msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
 DREF msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_RELEASED}: max total use count was 3
 DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
-DMSC msub(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342) MSC-A terminated
-DMSC msub(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342) 1 MSC-I still active
+DMSC msub(IMSI-901700000004620:MSISDN-46071) MSC-A terminated
+DMSC msub(IMSI-901700000004620:MSISDN-46071) 1 MSC-I still active
 DMSC msub_fsm{active}: state_chg to terminating
 DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU))
 DMSC dummy_msc_i(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU))
 DMSC dummy_msc_i(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){0}: Removing from parent msub_fsm
 DMSC dummy_msc_i(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){0}: Deferring: will deallocate with msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU)
-DMSC msub(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342) Free
-DREF VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 - active-conn: now used by 1 (attached)
+DMSC msub(IMSI-901700000004620:MSISDN-46071) Free
+DREF VLR subscr IMSI-901700000004620:MSISDN-46071 - active-conn: now used by 1 (attached)
 DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU)
 DMSC msc_a(IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342:GERAN-A:LU){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
 - msub gone
   llist_count(&msub_list) == 0
-DVLR freeing VLR subscr IMSI-901700000004620:MSISDN-46071:TMSI-0x23422342 (max total use count was 5)
+DVLR freeing VLR subscr IMSI-901700000004620:MSISDN-46071 (max total use count was 5)
 ===== test_lu_unknown_tmsi: SUCCESS