msc/USSD: expect and reply SS/USSD messages over GSUP

As we are about to finish the implementation of GSM TS 09.11,
OsmoMSC will forward all SS/USSD messages over GSUP to HLR,
and will expect responses back from HLR. The SS/USSD payload
processing will be out of scope for OsmoMSC itself.

Let's modify the existing test cases in order to expect and
reply SS/USSD messages over GSUP protocol.

Change-Id: I01de73aced6057328a121577a5a83bc2615fb2d4

1 files changed, 81 insertions, 40 deletions

diff --git a/msc/MSC_Tests.ttcn b/msc/MSC_Tests.ttcn
index 640940d2..e7c0a2ac 100644
--- a/msc/MSC_Tests.ttcn
+++ b/msc/MSC_Tests.ttcn
@@ -2194,40 +2194,62 @@ runs on BSC_ConnHdlr {
 	/* Send CM Service Request for SS/USSD */
 	f_establish_fully(EST_TYPE_SS_ACT);
 
+	/* We need to inspect GSUP activity */
+	f_create_gsup_expect(hex2str(g_pars.imsi));
+
+	var template OCTN facility_req := f_USSD_FACILITY_IE_INVOKE(
+		invoke_id := 5, /* Phone may not start from 0 or 1 */
+		op_code := SS_OP_CODE_PROCESS_USS_REQ,
+		ussd_string := "*#100#"
+	);
+
+	var template OCTN facility_rsp := f_USSD_FACILITY_IE_RETURN_RESULT(
+		invoke_id := 5, /* InvokeID shall be the same for both REQ and RSP */
+		op_code := SS_OP_CODE_PROCESS_USS_REQ,
+		ussd_string := "Your extension is " & hex2str(g_pars.msisdn) & "\r"
+	)
+
 	/* Compose a new SS/REGISTER message with request */
 	var template (value) PDU_ML3_MS_NW ussd_req := ts_ML3_MO_SS_REGISTER(
 		tid := 1, /* We just need a single transaction */
 		ti_flag := c_TIF_ORIG, /* Sent from the side that originates the TI */
-		facility := f_USSD_FACILITY_IE_INVOKE(
-			invoke_id := 5, /* Phone may not start from 0 or 1 */
-			op_code := SS_OP_CODE_PROCESS_USS_REQ,
-			ussd_string := "*#100#"
-		)
+		facility := valueof(facility_req)
 	);
 
 	/* Compose SS/RELEASE_COMPLETE template with expected response */
 	var template PDU_ML3_NW_MS ussd_rsp := tr_ML3_MT_SS_RELEASE_COMPLETE(
 		tid := 1, /* Response should arrive within the same transaction */
 		ti_flag := c_TIF_REPL, /* Sent to the side that originates the TI */
-		facility := f_USSD_FACILITY_IE_RETURN_RESULT(
-			invoke_id := 5, /* InvokeID shall be the same for both REQ and RSP */
-			op_code := SS_OP_CODE_PROCESS_USS_REQ,
-			ussd_string := "Your extension is " & hex2str(g_pars.msisdn) & "\r"
-		)
+		facility := valueof(facility_rsp)
 	);
 
-	/* Request own number request */
+	/* Compose expected MSC -> HLR message */
+	var template GSUP_PDU gsup_req := tr_GSUP_PROC_SS_REQ(
+		imsi := g_pars.imsi,
+		state := OSMO_GSUP_SESSION_STATE_BEGIN,
+		ss := valueof(facility_req)
+	);
+
+	/* To be used for sending response with correct session ID */
+	var GSUP_PDU gsup_req_complete;
+
+	/* Request own number */
 	BSSAP.send(ts_PDU_DTAP_MO(ussd_req));
-	alt {
-	/* We expect RELEASE_COMPLETE message with the response */
-	[] BSSAP.receive(tr_PDU_DTAP_MT(ussd_rsp)) {
-		setverdict(pass);
-		}
-	[] BSSAP.receive {
-		setverdict(fail, "Unknown/unexpected BSSAP received");
-		mtc.stop;
-		}
-	}
+	/* Expect GSUP message containing the SS payload */
+	gsup_req_complete := f_expect_gsup_msg(gsup_req);
+
+	/* Compose the response from HLR using received session ID */
+	var template GSUP_PDU gsup_rsp := ts_GSUP_PROC_SS_REQ(
+		imsi := g_pars.imsi,
+		sid := gsup_req_complete.ies[1].val.session_id,
+		state := OSMO_GSUP_SESSION_STATE_END,
+		ss := valueof(facility_rsp)
+	);
+
+	/* Finally, HLR terminates the session */
+	GSUP.send(gsup_rsp);
+	/* Expect RELEASE_COMPLETE message with the response */
+	f_expect_mt_dtap_msg(ussd_rsp);
 
 	f_expect_clear();
 }
@@ -2259,38 +2281,57 @@ runs on BSC_ConnHdlr {
 	/* Hold the call for some time */
 	f_sleep(1.0);
 
+	var template OCTN facility_req := f_USSD_FACILITY_IE_INVOKE(
+		op_code := SS_OP_CODE_PROCESS_USS_REQ,
+		ussd_string := "*#100#"
+	);
+
+	var template OCTN facility_rsp := f_USSD_FACILITY_IE_RETURN_RESULT(
+		op_code := SS_OP_CODE_PROCESS_USS_REQ,
+		ussd_string := "Your extension is " & hex2str(g_pars.msisdn) & "\r"
+	)
+
 	/* Compose a new SS/REGISTER message with request */
 	var template (value) PDU_ML3_MS_NW ussd_req := ts_ML3_MO_SS_REGISTER(
 		tid := 1, /* We just need a single transaction */
 		ti_flag := c_TIF_ORIG, /* Sent from the side that originates the TI */
-		facility := f_USSD_FACILITY_IE_INVOKE(
-			op_code := SS_OP_CODE_PROCESS_USS_REQ,
-			ussd_string := "*#100#"
-		)
+		facility := valueof(facility_req)
 	);
 
 	/* Compose SS/RELEASE_COMPLETE template with expected response */
 	var template PDU_ML3_NW_MS ussd_rsp := tr_ML3_MT_SS_RELEASE_COMPLETE(
 		tid := 1, /* Response should arrive within the same transaction */
 		ti_flag := c_TIF_REPL, /* Sent to the side that originates the TI */
-		facility := f_USSD_FACILITY_IE_RETURN_RESULT(
-			op_code := SS_OP_CODE_PROCESS_USS_REQ,
-			ussd_string := "Your extension is " & hex2str(g_pars.msisdn) & "\r"
-		)
+		facility := valueof(facility_rsp)
 	);
 
-	/* Request own number request */
+	/* Compose expected MSC -> HLR message */
+	var template GSUP_PDU gsup_req := tr_GSUP_PROC_SS_REQ(
+		imsi := g_pars.imsi,
+		state := OSMO_GSUP_SESSION_STATE_BEGIN,
+		ss := valueof(facility_req)
+	);
+
+	/* To be used for sending response with correct session ID */
+	var GSUP_PDU gsup_req_complete;
+
+	/* Request own number */
 	BSSAP.send(ts_PDU_DTAP_MO(ussd_req));
-	alt {
-	/* We expect RELEASE_COMPLETE message with the response */
-	[] BSSAP.receive(tr_PDU_DTAP_MT(ussd_rsp)) {
-		setverdict(pass);
-		}
-	[] BSSAP.receive {
-		setverdict(fail, "Unknown/unexpected BSSAP received");
-		mtc.stop;
-		}
-	}
+	/* Expect GSUP message containing the SS payload */
+	gsup_req_complete := f_expect_gsup_msg(gsup_req);
+
+	/* Compose the response from HLR using received session ID */
+	var template GSUP_PDU gsup_rsp := ts_GSUP_PROC_SS_REQ(
+		imsi := g_pars.imsi,
+		sid := gsup_req_complete.ies[1].val.session_id,
+		state := OSMO_GSUP_SESSION_STATE_END,
+		ss := valueof(facility_rsp)
+	);
+
+	/* Finally, HLR terminates the session */
+	GSUP.send(gsup_rsp);
+	/* Expect RELEASE_COMPLETE message with the response */
+	f_expect_mt_dtap_msg(ussd_rsp);
 
 	/* Hold the call for some time */
 	f_sleep(1.0);