library/GSUP_Types.ttcn: SS Info IE is optional for GSUP_PROC_SS_*

The 'SS Info' IE is optional for GSUP_PROC_SS_{REQ|RSP} messages,
and is not carried in some cases, e.g. when a subscriber aborts
an active transaction by pressing the 'red button'.

Change-Id: I20d9028acbe0c457d2a2cf72eff372b749d8dc30

1 files changed, 51 insertions, 28 deletions

diff --git a/library/GSUP_Types.ttcn b/library/GSUP_Types.ttcn
index 359e272a..60445652 100644
--- a/library/GSUP_Types.ttcn
+++ b/library/GSUP_Types.ttcn
@@ -581,62 +581,85 @@ template GSUP_IE tr_GSUP_IE_SSInfo(template octetstring ss) := {
 	}
 }
 
-template (value) GSUP_PDU ts_GSUP_PROC_SS_REQ(
+private function f_gen_ts_ss_ies(
 	hexstring imsi,
 	OCT4 sid,
 	GSUP_SessionState state,
-	octetstring ss
-) := ts_GSUP(
-	OSMO_GSUP_MSGT_PROC_SS_REQUEST,
-	{
+	template (omit) octetstring ss
+) return GSUP_IEs {
+	/* Mandatory IEs */
+	var GSUP_IEs ies := {
 		valueof(ts_GSUP_IE_IMSI(imsi)),
 		valueof(ts_GSUP_IE_SessionId(sid)),
-		valueof(ts_GSUP_IE_SessionState(state)),
-		valueof(ts_GSUP_IE_SSInfo(ss))
+		valueof(ts_GSUP_IE_SessionState(state))
+	};
+
+	/* Optional SS payload */
+	if (isvalue(ss)) {
+		ies[3] := valueof(ts_GSUP_IE_SSInfo(valueof(ss)));
 	}
-);
-template GSUP_PDU tr_GSUP_PROC_SS_REQ(
+
+	return ies;
+}
+private function f_gen_tr_ss_ies(
 	template hexstring imsi,
 	template OCT4 sid := ?,
 	template GSUP_SessionState state := ?,
 	template octetstring ss := ?
-) := tr_GSUP(
-	OSMO_GSUP_MSGT_PROC_SS_REQUEST,
-	{
+) return template GSUP_IEs {
+	/* Mandatory IEs */
+	var template GSUP_IEs ies := {
 		tr_GSUP_IE_IMSI(imsi),
 		tr_GSUP_IE_SessionId(sid),
-		tr_GSUP_IE_SessionState(state),
-		tr_GSUP_IE_SSInfo(ss)
+		tr_GSUP_IE_SessionState(state)
+	};
+
+	/* Optional SS payload */
+	if (istemplatekind(ss, "*")) {
+		ies[3] := *;
+	} else if (not istemplatekind(ss, "omit")) {
+		ies[3] := tr_GSUP_IE_SSInfo(ss);
 	}
+
+	return ies;
+}
+
+template (value) GSUP_PDU ts_GSUP_PROC_SS_REQ(
+	hexstring imsi,
+	OCT4 sid,
+	GSUP_SessionState state,
+	template (omit) octetstring ss := omit
+) := ts_GSUP(
+	OSMO_GSUP_MSGT_PROC_SS_REQUEST,
+	f_gen_ts_ss_ies(imsi, sid, state, ss)
+);
+template GSUP_PDU tr_GSUP_PROC_SS_REQ(
+	template hexstring imsi,
+	template OCT4 sid := ?,
+	template GSUP_SessionState state := ?,
+	template octetstring ss := *
+) := tr_GSUP(
+	OSMO_GSUP_MSGT_PROC_SS_REQUEST,
+	f_gen_tr_ss_ies(imsi, sid, state, ss)
 );
 
 template (value) GSUP_PDU ts_GSUP_PROC_SS_RES(
 	hexstring imsi,
 	OCT4 sid,
 	GSUP_SessionState state,
-	octetstring ss
+	template (omit) octetstring ss := omit
 ) := ts_GSUP(
 	OSMO_GSUP_MSGT_PROC_SS_RESULT,
-	{
-		valueof(ts_GSUP_IE_IMSI(imsi)),
-		valueof(ts_GSUP_IE_SessionId(sid)),
-		valueof(ts_GSUP_IE_SessionState(state)),
-		valueof(ts_GSUP_IE_SSInfo(ss))
-	}
+	f_gen_ts_ss_ies(imsi, sid, state, ss)
 );
 template GSUP_PDU tr_GSUP_PROC_SS_RES(
 	template hexstring imsi,
 	template OCT4 sid := ?,
 	template GSUP_SessionState state := ?,
-	template octetstring ss := ?
+	template octetstring ss := *
 ) := tr_GSUP(
 	OSMO_GSUP_MSGT_PROC_SS_RESULT,
-	{
-		tr_GSUP_IE_IMSI(imsi),
-		tr_GSUP_IE_SessionId(sid),
-		tr_GSUP_IE_SessionState(state),
-		tr_GSUP_IE_SSInfo(ss)
-	}
+	f_gen_tr_ss_ies(imsi, sid, state, ss)
 );
 
 template (value) GSUP_PDU ts_GSUP_PROC_SS_ERR(