implement periodic Location Update expiry in the VLR

Remove subscribers which fail to send periodic Location Updates from the
list of subscribers known to the VLR. This complements the IMSI detach
procedure: periodic LU expiry triggers an implicit IMSI detach.

Expired subscribers are purged from a periodic timer which iterates
over all subscribers once per minute.

Subscribers with an active connection do not expire. This is controlled
by the subscriber conn FSM which sets a subscriber's the LU expiry timeout
value to GSM_SUBSCRIBER_NO_EXPIRATION while a connection is active.

Add support for fake time with osmo_clock_gettime() to msc_vlr tests.

This functionality existed in OpenBSC but was lost during the nitb split.
This code took some inspiration from the OpenBSC implementation.

Related: OS#1976
Change-Id: Iebdee8b12d22acfcfb265ee41e71cfc8d9eb3ba9

4 files changed, 193 insertions, 0 deletions

diff --git a/tests/msc_vlr/msc_vlr_test_no_authen.c b/tests/msc_vlr/msc_vlr_test_no_authen.c
index cd61fa127..85c01d9d2 100644
--- a/tests/msc_vlr/msc_vlr_test_no_authen.c
+++ b/tests/msc_vlr/msc_vlr_test_no_authen.c
@@ -917,6 +917,64 @@ static void test_no_authen_imeisv_tmsi_imei()
 	comment_end();
 }
 
+static void test_no_authen_subscr_expire()
+{
+	struct vlr_subscr *vsub;
+	const char *imsi = "901700000004620";
+
+	/* No auth only works on GERAN */
+	rx_from_ran = RAN_GERAN_A;
+
+	comment_start();
+
+	fake_time_start();
+
+	/* The test framework has already started the VLR before fake time was active.
+	 * Manually schedule this timeout in fake time. */
+	osmo_timer_del(&net->vlr->lu_expire_timer);
+	osmo_timer_schedule(&net->vlr->lu_expire_timer, VLR_SUBSCRIBER_LU_EXPIRATION_INTERVAL, 0);
+
+	/* Let the LU expiration timer tick once */
+	fake_time_passes(VLR_SUBSCRIBER_LU_EXPIRATION_INTERVAL + 1, 0);
+
+	btw("Location Update request causes a GSUP LU request to HLR");
+	lu_result_sent = RES_NONE;
+	gsup_expect_tx("04010809710000004026f0");
+	ms_sends_msg("050802008168000130089910070000006402");
+	OSMO_ASSERT(gsup_tx_confirmed);
+	VERBOSE_ASSERT(lu_result_sent, == RES_NONE, "%d");
+
+	btw("HLR sends _INSERT_DATA_REQUEST, VLR responds with _INSERT_DATA_RESULT");
+	gsup_rx("10010809710000004026f00804036470f1",
+		"12010809710000004026f0");
+	VERBOSE_ASSERT(lu_result_sent, == RES_NONE, "%d");
+
+	btw("HLR also sends GSUP _UPDATE_LOCATION_RESULT");
+	expect_bssap_clear();
+	gsup_rx("06010809710000004026f0", NULL);
+
+	btw("LU was successful, and the conn has already been closed");
+	VERBOSE_ASSERT(lu_result_sent, == RES_ACCEPT, "%d");
+	VERBOSE_ASSERT(bssap_clear_sent, == true, "%d");
+
+	bss_sends_clear_complete();
+	EXPECT_CONN_COUNT(0);
+
+	vsub = vlr_subscr_find_by_imsi(net->vlr, imsi);
+	OSMO_ASSERT(vsub);
+	vlr_subscr_put(vsub);
+
+	/* Let T3212 (periodic Location update timer) expire */
+	fake_time_passes((net->t3212 * 60 * 6 * 2) + 60*4, 0);
+
+	/* The subscriber should now be gone. */
+	vsub = vlr_subscr_find_by_imsi(net->vlr, imsi);
+	OSMO_ASSERT(vsub == NULL);
+
+	EXPECT_CONN_COUNT(0);
+	clear_vlr();
+	comment_end();
+}
 
 msc_vlr_test_func_t msc_vlr_tests[] = {
 	test_no_authen,
@@ -927,5 +985,6 @@ msc_vlr_test_func_t msc_vlr_tests[] = {
 	test_no_authen_imeisv_imei,
 	test_no_authen_imeisv_tmsi,
 	test_no_authen_imeisv_tmsi_imei,
+	test_no_authen_subscr_expire,
 	NULL
 };
diff --git a/tests/msc_vlr/msc_vlr_test_no_authen.err b/tests/msc_vlr/msc_vlr_test_no_authen.err
index 2890e96f3..8d9d4979f 100644
--- a/tests/msc_vlr/msc_vlr_test_no_authen.err
+++ b/tests/msc_vlr/msc_vlr_test_no_authen.err
@@ -2270,6 +2270,132 @@ DMM Subscr_Conn{SUBSCR_CONN_S_RELEASED}: Deallocated
 full talloc report on 'msgb' (total      0 bytes in   1 blocks)
 talloc_total_blocks(tall_bsc_ctx) == 12
 
+===== test_no_authen_subscr_expire
+- Total time passed: 0.000000 s
+- Total time passed: 61.000000 s
+- Location Update request causes a GSUP LU request to HLR
+  MSC <--RAN_GERAN_A-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
+  new conn
+DMM Subscr_Conn{SUBSCR_CONN_S_NEW}: Allocated
+DREF unknown: MSC conn use + compl_l3 == 1 (0x1: compl_l3)
+DRLL Dispatching 04.08 message GSM48_MT_MM_LOC_UPD_REQUEST (0x5:0x8)
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_NEW}: Updated ID
+DMM LOCATION UPDATING REQUEST: MI(IMSI)=901700000004620 type=IMSI ATTACH
+DMM LU/new-LAC: 1/23
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: Allocated
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: is child of Subscr_Conn(LU:901700000004620)
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: rev=GSM net=GERAN (no Auth)
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: Received Event VLR_ULA_E_UPDATE_LA
+DREF VLR subscr unknown usage increases to: 1
+DVLR set IMSI on subscriber; IMSI=901700000004620 id=901700000004620
+DVLR New subscr, IMSI: 901700000004620
+DREF VLR subscr IMSI:901700000004620 usage increases to: 2
+DREF VLR subscr IMSI:901700000004620 usage decreases to: 1
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: vlr_loc_upd_node1()
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: vlr_loc_upd_post_auth()
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: vlr_loc_upd_post_ciph()
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: vlr_loc_upd_node_4()
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_IDLE}: state_chg to VLR_ULA_S_WAIT_HLR_UPD
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_INIT}: Allocated
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_INIT}: is child of vlr_lu_fsm(LU:901700000004620)
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_INIT}: Received Event UPD_HLR_VLR_E_START
+DVLR GSUP tx: 04010809710000004026f0
+GSUP --> HLR: OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST: 04010809710000004026f0
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_INIT}: state_chg to UPD_HLR_VLR_S_WAIT_FOR_DATA
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_NEW}: Received Event SUBSCR_CONN_E_COMPLETE_LAYER_3
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_NEW}: state_chg to SUBSCR_CONN_S_AUTH_CIPH
+DREF IMSI:901700000004620: MSC conn use - compl_l3 == 0 (0x0: )
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_AUTH_CIPH}: Received Event SUBSCR_CONN_E_UNUSED
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_AUTH_CIPH}: Awaiting results for Auth+Ciph, overruling event SUBSCR_CONN_E_UNUSED
+  lu_result_sent == 0
+- HLR sends _INSERT_DATA_REQUEST, VLR responds with _INSERT_DATA_RESULT
+<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: 10010809710000004026f00804036470f1
+DVLR GSUP rx 17: 10010809710000004026f00804036470f1
+DREF VLR subscr IMSI:901700000004620 usage increases to: 2
+DVLR IMSI:901700000004620 has MSISDN:46071
+DVLR SUBSCR(MSISDN:46071) VLR: update for IMSI=901700000004620 (MSISDN=46071, used=2)
+DVLR GSUP tx: 12010809710000004026f0
+GSUP --> HLR: OSMO_GSUP_MSGT_INSERT_DATA_RESULT: 12010809710000004026f0
+DREF VLR subscr MSISDN:46071 usage decreases to: 1
+<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: vlr_gsupc_read_cb() returns 0
+  lu_result_sent == 0
+- HLR also sends GSUP _UPDATE_LOCATION_RESULT
+<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: 06010809710000004026f0
+DVLR GSUP rx 11: 06010809710000004026f0
+DREF VLR subscr MSISDN:46071 usage increases to: 2
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_HLR_LU_RES
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_WAIT_FOR_DATA}: Received Event UPD_HLR_VLR_E_UPD_LOC_ACK
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_WAIT_FOR_DATA}: state_chg to UPD_HLR_VLR_S_DONE
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_DONE}: Removing from parent vlr_lu_fsm(LU:901700000004620)
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_DONE}: Freeing instance
+DVLR upd_hlr_vlr_fsm(LU:901700000004620){UPD_HLR_VLR_S_DONE}: Deallocated
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_UPD_HLR_COMPL
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_WAIT_HLR_UPD}: state_chg to VLR_ULA_S_WAIT_LU_COMPL
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_INIT}: Allocated
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_INIT}: is child of vlr_lu_fsm(LU:901700000004620)
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_INIT}: Received Event LU_COMPL_VLR_E_START
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_INIT}: state_chg to LU_COMPL_VLR_S_WAIT_SUB_PRES
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_INIT}: Allocated
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_INIT}: is child of lu_compl_vlr_fsm(LU:901700000004620)
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_INIT}: Received Event SUB_PRES_VLR_E_START
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_INIT}: state_chg to SUB_PRES_VLR_S_DONE
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_DONE}: Removing from parent lu_compl_vlr_fsm(LU:901700000004620)
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_DONE}: Freeing instance
+DVLR sub_pres_vlr_fsm(LU:901700000004620){SUB_PRES_VLR_S_DONE}: Deallocated
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_WAIT_SUB_PRES}: Received Event LU_COMPL_VLR_E_SUB_PRES_COMPL
+- sending LU Accept for MSISDN:46071
+DREF VLR subscr MSISDN:46071 usage increases to: 3
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_DONE
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_DONE}: Removing from parent vlr_lu_fsm(LU:901700000004620)
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_DONE}: Freeing instance
+DVLR lu_compl_vlr_fsm(LU:901700000004620){LU_COMPL_VLR_S_DONE}: Deallocated
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_WAIT_LU_COMPL}: state_chg to VLR_ULA_S_DONE
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_AUTH_CIPH}: Received Event SUBSCR_CONN_E_ACCEPTED
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_AUTH_CIPH}: state_chg to SUBSCR_CONN_S_ACCEPTED
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_ACCEPTED}: Received Event SUBSCR_CONN_E_UNUSED
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_ACCEPTED}: state_chg to SUBSCR_CONN_S_RELEASING
+DREF MSISDN:46071: MSC conn use + release == 1 (0x100: release)
+DREF VLR subscr MSISDN:46071 usage increases to: 4
+DREF VLR subscr MSISDN:46071 usage decreases to: 3
+- BSSAP Clear --RAN_GERAN_A--> MS
+DREF VLR subscr MSISDN:46071 usage decreases to: 2
+<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: vlr_gsupc_read_cb() returns 0
+- LU was successful, and the conn has already been closed
+  lu_result_sent == 1
+  bssap_clear_sent == 1
+- BSS sends BSSMAP Clear Complete
+DREF MSISDN:46071: MSC conn use - release == 0 (0x0: )
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_RELEASING}: Received Event SUBSCR_CONN_E_UNUSED
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_RELEASING}: state_chg to SUBSCR_CONN_S_RELEASED
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_DONE}: Removing from parent Subscr_Conn(LU:901700000004620)
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_DONE}: fsm_lu_cleanup called with cause OSMO_FSM_TERM_PARENT
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_DONE}: Freeing instance
+DVLR vlr_lu_fsm(LU:901700000004620){VLR_ULA_S_DONE}: Deallocated
+DRLL MSISDN:46071: Freeing subscriber connection
+DREF VLR subscr MSISDN:46071 usage decreases to: 1
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_RELEASED}: Freeing instance
+DMM Subscr_Conn(LU:901700000004620){SUBSCR_CONN_S_RELEASED}: Deallocated
+  llist_count(&net->subscr_conns) == 0
+DREF VLR subscr MSISDN:46071 usage increases to: 2
+DREF VLR subscr MSISDN:46071 usage decreases to: 1
+- Total time passed: 3901.000000 s
+DVLR MSISDN:46071: Location Update expired
+DREF VLR subscr MSISDN:46071 usage increases to: 2
+DREF VLR subscr MSISDN:46071 usage decreases to: 1
+DREF VLR subscr MSISDN:46071 usage decreases to: 0
+DREF freeing VLR subscr MSISDN:46071
+  llist_count(&net->subscr_conns) == 0
+===== test_no_authen_subscr_expire: SUCCESS
+
+full talloc report on 'msgb' (total      0 bytes in   1 blocks)
+talloc_total_blocks(tall_bsc_ctx) == 12
+
 full talloc report on 'msgb' (total      0 bytes in   1 blocks)
 talloc_total_blocks(tall_bsc_ctx) == 12
 
diff --git a/tests/msc_vlr/msc_vlr_tests.c b/tests/msc_vlr/msc_vlr_tests.c
index 5c0189642..8910e328e 100644
--- a/tests/msc_vlr/msc_vlr_tests.c
+++ b/tests/msc_vlr/msc_vlr_tests.c
@@ -813,8 +813,15 @@ const struct timeval fake_time_start_time = { 123, 456 };
 
 void fake_time_start()
 {
+	struct timespec *clock_override;
+
 	osmo_gettimeofday_override_time = fake_time_start_time;
 	osmo_gettimeofday_override = true;
+	clock_override = osmo_clock_override_gettimespec(CLOCK_MONOTONIC);
+	OSMO_ASSERT(clock_override);
+	clock_override->tv_sec = fake_time_start_time.tv_sec;
+	clock_override->tv_nsec = fake_time_start_time.tv_usec * 1000;
+	osmo_clock_override_enable(CLOCK_MONOTONIC, true);
 	fake_time_passes(0, 0);
 }
 
diff --git a/tests/msc_vlr/msc_vlr_tests.h b/tests/msc_vlr/msc_vlr_tests.h
index a29e87065..a62cffa5e 100644
--- a/tests/msc_vlr/msc_vlr_tests.h
+++ b/tests/msc_vlr/msc_vlr_tests.h
@@ -218,6 +218,7 @@ void fake_time_start();
 { \
 	struct timeval diff; \
 	osmo_gettimeofday_override_add(secs, usecs); \
+	osmo_clock_override_add(CLOCK_MONOTONIC, secs, usecs * 1000); \
 	timersub(&osmo_gettimeofday_override_time, &fake_time_start_time, &diff); \
 	btw("Total time passed: %d.%06d s", \
 	    (int)diff.tv_sec, (int)diff.tv_usec); \