sgsn: Introduce test TC_pmm_idle_rx_mt_data

Change-Id: I35d660b8e546f6ce0af8c05d7b5c56833a26fb76
---
M sgsn/BSSGP_ConnHdlr.ttcn
M sgsn/SGSN_Tests_Iu.ttcn
M sgsn/expected-results.xml
3 files changed, 74 insertions(+), 4 deletions(-)

diff --git a/sgsn/BSSGP_ConnHdlr.ttcn b/sgsn/BSSGP_ConnHdlr.ttcn
index 0eb24e4..140fa99 100644
--- a/sgsn/BSSGP_ConnHdlr.ttcn
+++ b/sgsn/BSSGP_ConnHdlr.ttcn
@@ -720,6 +720,7 @@
 	octetstring		ggsn_ip_c,			/* GGSN IP Control */
 	octetstring		ggsn_ip_u,			/* GGSN IP User */
 	OCT1			ggsn_restart_ctr,		/* GGSN Restart Counter */
+	boolean			direct_tunnel_requested,	/* Did SGSN request Direct Tunnel to the GGSN ?*/
 
 	OCT4			rnc_tei_u,			/* SGSN TEI User */
 	octetstring		rnc_ip_u,			/* SGSN IP USer */
@@ -788,6 +789,7 @@
 		apars.sgsn_ip_u := upd.sgsn_addr_traffic.addressf;
 		apars.sgsn_tei_u := upd.teidDataI.teidDataI;
 	}
+	apars.direct_tunnel_requested := dti;
 }
 altstep as_ggsn_gtp_ctx_upd_req(inout PdpActPars apars,
 				boolean send_recovery := false,
@@ -1024,6 +1026,7 @@
 	ggsn_ip_c := f_inet_addr(ggsn_ip),
 	ggsn_ip_u := f_inet_addr(ggsn_ip),
 	ggsn_restart_ctr := int2oct(2, 1),
+	direct_tunnel_requested := false,
 
 	rnc_tei_u := f_rnd_octstring(4),
 	rnc_ip_u := f_inet_addr(rnc_ip),
@@ -1046,9 +1049,18 @@
 	remPort := GTP1C_PORT
 }
 
-function f_gtpu_send(inout PdpActPars apars, octetstring payload) runs on BSSGP_ConnHdlr {
-	var Gtp1uPeer peer := valueof(ts_GtpPeerU(apars.sgsn_ip_u));
-	GTP[GTP_GGSN_IDX].send(ts_GTP1U_GPDU(peer, 0 /*seq*/, apars.sgsn_tei_u, payload));
+/* Send data from GGSN to SGSN/RNC (depending on apars.f_ggsn_gtpu_send) */
+function f_ggsn_gtpu_send(inout PdpActPars apars, octetstring payload) runs on BSSGP_ConnHdlr {
+	var Gtp1uPeer peer;
+	var OCT4 rem_teid;
+	if (apars.direct_tunnel_requested) {
+		peer := valueof(ts_GtpPeerU(apars.rnc_ip_u));
+		rem_teid := apars.rnc_tei_u;
+	} else {
+		peer := valueof(ts_GtpPeerU(apars.sgsn_ip_u));
+		rem_teid := apars.sgsn_tei_u;
+	}
+	GTP[GTP_GGSN_IDX].send(ts_GTP1U_GPDU(peer, 0 /*seq*/, rem_teid, payload));
 }
 
 altstep as_xid(PdpActPars apars, integer ran_index := 0) runs on BSSGP_ConnHdlr {
@@ -1095,7 +1107,7 @@
 runs on BSSGP_ConnHdlr {
 	timer T := 5.0;
 	/* Send PDU via GTP from our simulated GGSN to the SGSN */
-	f_gtpu_send(apars, payload);
+	f_ggsn_gtpu_send(apars, payload);
 	T.start;
 
 	alt {
diff --git a/sgsn/SGSN_Tests_Iu.ttcn b/sgsn/SGSN_Tests_Iu.ttcn
index a6398eb..5010443 100644
--- a/sgsn/SGSN_Tests_Iu.ttcn
+++ b/sgsn/SGSN_Tests_Iu.ttcn
@@ -12,6 +12,9 @@
 import from RANAP_PDU_Descriptions all;
 import from RANAP_IEs all;
 
+import from GTPv1U_Templates all;
+import from GTP_Emulation all;
+
 import from BSSGP_ConnHdlr all;
 
 private function f_init() runs on test_CT {
@@ -215,6 +218,50 @@
 	f_cleanup();
 }
 
+/* Test UE going to PMM IDLE state after having activated the PDP context.
+ * SGSN is expected to update the GGSN cancelling the Direct Tunnel feature. */
+private function f_TC_pmm_idle_rx_mt_data(charstring id) runs on BSSGP_ConnHdlr {
+	var PdpActPars apars := valueof(t_PdpActPars(mp_ggsn_ip, mp_ranap_cfg[0].sctp_addr.local_ip_addr));
+
+	/* first perform regular attach */
+	f_gmm_attach(umts_aka_challenge := true, force_gsm_sres := false, ran_index := 3);
+
+	f_service_request(apars, ran_index := 3);
+
+	f_pdp_ctx_act(apars, ran_index := 3);
+
+	f_iu_release_req(ts_RanapCause_radio_conn_release);
+	/* Now UE is in PMM IDLE state at the SGSN.
+	 * Expect SGSN to point GTPU at GGSN back to itself: */
+	as_ggsn_gtp_ctx_upd_req(apars, exp_dir_tun := false, ran_index := 3);
+
+	/* Now GGSN receives new MT data and forwards it to SGSN: */
+	f_gtp_register_teid('00000000'O, GTP_GGSN_IDX); /* Ease debugging in case SGSN sends ErrorInd */
+	f_ran_register_imsi(g_pars.imsi, g_pars.p_tmsi); /* Forward Paging below to this component */
+	var octetstring payload := f_rnd_octstring(100);
+	f_ggsn_gtpu_send(apars, payload);
+
+	BSSAP.receive(tr_RANAP_Paging(ps_domain, imsi_hex2oct(g_pars.imsi)));
+
+	/* Ue comes back, answering the paging:
+	 * SGSN recreates the Iu ctx and recovers the Direct Tunnel RNC<->GGSN: */
+	f_service_request(apars, pdp_status := '2000'O /*NSAPI=5*/, ran_index := 3);
+	as_ranap_rab_ass_req(apars);
+	as_ggsn_gtp_ctx_upd_req(apars, exp_dir_tun := true, ran_index := 3);
+
+	/* Now UE is in PMM ENABLED state, tear it down to clean up: */
+	f_pdp_ctx_deact_mo(apars, '00'O, ran_index := 3);
+	setverdict(pass);
+}
+testcase TC_pmm_idle_rx_mt_data() runs on test_CT {
+	var BSSGP_ConnHdlr vc_conn;
+	f_init();
+	f_sleep(1.0);
+	vc_conn := f_start_handler(refers(f_TC_pmm_idle_rx_mt_data), testcasename(), g_gb, 1007);
+	vc_conn.done;
+	f_cleanup();
+}
+
 control {
 	execute( TC_iu_attach() );
 	execute( TC_iu_attach_encr() );
@@ -222,6 +269,7 @@
 	execute( TC_geran_attach_iu_rau() );
 	execute( TC_attach_pdp_act_user() );
 	execute( TC_attach_pdp_act_pmm_idle() );
+	execute( TC_pmm_idle_rx_mt_data() );
 }
 
 
diff --git a/sgsn/expected-results.xml b/sgsn/expected-results.xml
index 7b38e99..3461721 100644
--- a/sgsn/expected-results.xml
+++ b/sgsn/expected-results.xml
@@ -95,6 +95,7 @@
   <testcase classname='SGSN_Tests_Iu' name='TC_attach_pdp_act_user' time='MASKED'/>
   <testcase classname='SGSN_Tests_Iu' name='TC_attach_pdp_act_pmm_idle' time='MASKED'/>
   <testcase classname='SGSN_Tests_Iu' name='TC_attach_pdp_act_pmm_idle_lost_pdp_status' time='MASKED'/>
+  <testcase classname='SGSN_Tests_Iu' name='TC_pmm_idle_rx_mt_data' time='MASKED'/>
   <!-- SGSN_Tests_NS (handle_sns == true) testcases start here -->
   <testcase classname='SGSN_Tests_NS' name='TC_SNS_size' time='MASKED'/>
   <testcase classname='SGSN_Tests_NS' name='TC_SNS_size_too_big' time='MASKED'/>

