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

1 files changed, 59 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
 };