gbproxy: Introduce TC_overload

When the SGSN is sending an OVERLOAD message, we expect that to
propagate down to every BSS on the other side.

Change-Id: Ic61fabd9c633bcb3f256fe7aa5834e66cc66a4fb

gbproxy/GBProxy_Tests.ttcn

@@ -1905,6 +1905,35 @@ testcase TC_llc_discarded() runs on test_CT
 	f_cleanup();
 }
 
+/* Send an OVERLOAD from SGSN side and expect it to show up on each PCU (SIG BVC) */
+testcase TC_overload() runs on GlobalTest_CT
+{
+	f_init();
+	f_global_init();
+
+	var template (value) PDU_BSSGP pdu_tx := ts_OVERLOAD('1'B);
+	var template (present) PDU_BSSGP exp_rx := tr_OVERLOAD('1'B);
+
+	var ro_default defaults := {};
+	for (var integer i := 0; i < lengthof(g_pcu); i := i+1) {
+		activate(as_bssgp_g_pcu_count(i, exp_rx, g_roi));
+	}
+	G_SGSN[0].send(pdu_tx);
+	f_sleep(2.0);
+	for (var integer i := 0; i < lengthof(defaults); i := i+1) {
+		deactivate(defaults[i]);
+	}
+
+	for (var integer i := 0; i < lengthof(g_pcu); i := i+1) {
+		if (not ro_integer_contains(g_roi, i)) {
+			setverdict(fail, "Failed to receive OVERLOAD on PCU index ", i);
+		}
+	}
+	setverdict(pass);
+
+	f_cleanup();
+}
+
 private function f_block_ptp_bvc_from_pcu(integer pcu_idx, integer bvc_idx) runs on test_CT
 {
 	var BSSGP_BVC_CT bvc_ct := g_pcu[pcu_idx].vc_BSSGP_BVC[bvc_idx];
@@ -2138,6 +2167,7 @@ control {
 	execute( TC_resume() );
 	execute( TC_trace() );
 	execute( TC_llc_discarded() );
+	execute( TC_overload() );
 	execute( TC_bvc_block_ptp() );
 	execute( TC_bvc_unblock_ptp() );
 	execute( TC_bvc_reset_ptp_from_bss() );

library/BSSGP_Emulation.ttcnpp

@@ -302,7 +302,7 @@ altstep as_sig_wait_reset() runs on BSSGP_CT {
 private template PDU_BSSGP tr_GLOBAL := (
 	{pDU_BSSGP_SUSPEND:=?}, {pDU_BSSGP_SUSPEND_ACK:=?}, {pDU_BSSGP_SUSPEND_NACK:=?},
 	{pDU_BSSGP_RESUME:=?}, {pDU_BSSGP_RESUME_ACK:=?}, {pDU_BSSGP_RESUME_NACK:=?},
-	{pDU_BSSGP_SGSN_INVOKE_TRACE:=?}
+	{pDU_BSSGP_SGSN_INVOKE_TRACE:=?}, {pDU_BSSGP_OVERLOAD:=?}
 );
 
 /* We are in BVC_S_UNBLOCKED state */

library/Osmocom_Gb_Types.ttcn

@@ -2077,6 +2077,38 @@ octetstring sdu) := {
 		}
 	}
 
+	/* 10.4.36 */
+	template (value) PDU_BSSGP
+	ts_OVERLOAD(template (value) BIT1 priority_class) := {
+		pDU_BSSGP_OVERLOAD := {
+			bssgpPduType := '42'O,
+			priority_Class_Indicator := {
+				iEI := '8f'O,
+				ext := '1'B,
+				lengthIndicator := {
+					length1 := 1
+				},
+				priority_Class_Indicator_Value := priority_class,
+				spare := '0000000'B
+			}
+		}
+	}
+	template (present) PDU_BSSGP
+	tr_OVERLOAD(template (present) BIT1 priority_class) := {
+		pDU_BSSGP_OVERLOAD := {
+			bssgpPduType := '42'O,
+			priority_Class_Indicator := {
+				iEI := '8f'O,
+				ext := '1'B,
+				lengthIndicator := {
+					length1 := 1
+				},
+				priority_Class_Indicator_Value := priority_class,
+				spare := '0000000'B
+			}
+		}
+	}
+
 	/* PDU permitted on PTP BVC only (TS 48.018 Section 5.4.1) */
 	template (present) PDU_BSSGP tr_BSSGP_PERMITTED_PTP_ONLY := (
 		{pDU_BSSGP_DL_UNITDATA := ?},