Adding GTP-U support to reply to ICMP from UE (2854ca1e) · Commits · INT - Core Network and Interoperability Testing / 5G Core / NAS

etc/AtsNGAP/AtsNGAP_GNB_p_net.cfg_

+3 −0

Changes for etc/AtsNGAP/AtsNGAP_GNB_p_net.cfg_: 3 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -50,6 +50,7 @@ LibNGAP_Pixits.PX_TIME_ZONE := '80'O # 0x40 for GMT+1, 0x80 for GMT+2
		# User plane probe (TC_NGAP_GNB_PDU_01): the UPF tunnel endpoint given to the gNB is this host on N3, and the UE pings it
		LibNGAP_Pixits.PX_TRANSPORT_LAYER_ADDRESS := '00001010101011100001001100001110'B # 10.174.19.14
		LibNGAP_Pixits.PX_UT_PING_HOST := "10.174.19.14"
		LibNGAP_Pics.PICS_USE_GTPU := true # The test system plays the UPF on N3 and checks the uplink G-PDUs (system.N3_gNB_1)

		LibNGAP_Pixits.PX_PDU_SESSION_ID := 1

		@@ -100,6 +101,8 @@ LogEventTypes:= Yes

		# Act as AMF, listen for incoming connections from gNB
		system.NGAP_gNB_1.params := "NGAP/SCTP(local_server=10.174.19.14,server_mode=1,local_port=38412,debug=1)"
		# N3 user plane (PICS_USE_GTPU): GTP-U on UDP port 2152 of this host; dst_ip is the N3 address of the gNB (Echo Responses, downlink)
		system.N3_gNB_1.params := "GTPU(auto_echo_reply=1)/UDP(src_port=2152,dst_ip=10.174.19.10,dst_port=2152)"

		# Open5GS pcap files
		# Do not forget to set LibNGAP_Pics.PICS_OFFLINE_MODE to true

ttcn/AtsNGAP/NGAP_Steps.ttcn

+112 −9

Changes for ttcn/AtsNGAP/NGAP_Steps.ttcn: 112 added lines, 9 removed lines.
Original line number	Diff line number	Diff line
		@@ -32,6 +32,11 @@ module NGAP_Steps { // TODO FSCOM f_xxx_UE_SecurityMode to be mmoved into NAG_NG

		// UpperTester
		import from UpperTesterCommon all;

		// LibGtpu
		import from LibGtpu_TypesAndValues all;
		import from LibGtpu_Templates all;
		import from LibGtpu_Functions all;
		import from UpperTesterPtcToMtcDefs all;
		import from UpperTesterFunctions all;

		@@ -855,22 +860,26 @@ module NGAP_Steps { // TODO FSCOM f_xxx_UE_SecurityMode to be mmoved into NAG_NG
		/**
		* @brief Have the real UE send user plane traffic over its data call: ping PX_UT_PING_HOST.
		* @details Unless PX_UT_PING_HOST is empty: asks the upper tester for PING (AT+QPING on the modem,
		* PX_UT_PING_COUNT echo requests, PX_UT_PING_TIMEOUT s each) and waits for its result, which is
		* only logged. The gNB is expected to forward the echo requests as uplink G-PDUs to the UPF
		* tunnel endpoint of the PDU session (PX_TRANSPORT_LAYER_ADDRESS, PX_GTP_TEID); as the test
		* system does not handle GTP-U yet, no reply comes back, and only a capture on the test system
		* host (UDP port 2152) shows whether they arrived.
		* PX_UT_PING_COUNT echo requests, PX_UT_PING_TIMEOUT s each) and waits for its result. The gNB is
		* expected to forward the echo requests as uplink G-PDUs to the UPF tunnel endpoint of the PDU
		* session (PX_TRANSPORT_LAYER_ADDRESS, PX_GTP_TEID). With PICS_USE_GTPU, the test system plays that
		* UPF: each G-PDU received on N3_P meanwhile is checked (f_NGAP_gnb_check_uplink_gpdu), and the
		* verdict is set to fail if one does not conform, or if none carries an echo request of the UE
		* although the modem ran the pings. Echo requests are not answered (no downlink user data yet).
		* The UE stays in CM-CONNECTED meanwhile: no NGAP signalling is expected. If the gNB nevertheless
		* asks for the release of the UE context (UE CONTEXT RELEASE REQUEST, e.g. user inactivity when the
		* UE sends nothing), it is released (UE CONTEXT RELEASE COMMAND/COMPLETE) and the wait goes on:
		* left unanswered, the request would end in an NG RESET from the gNB.
		* @note The verdict is set by the UT dispatcher only (NGAP_UtDispatcher): inconc if the modem could not
		* run the pings at all (e.g. the context of the data call is not usable by AT+QPING); lost
		* replies are not a failure.
		* @return true if the modem ran the pings.
		* @note Lost replies are not a failure. The UT dispatcher (NGAP_UtDispatcher) sets the verdict to inconc
		* if the modem could not run the pings at all (e.g. the context of the data call is not usable by
		* AT+QPING).
		* @return true if the modem ran the pings and, with PICS_USE_GTPU, the uplink user data was conformant.
		*/
		function f_NGAP_gnb_UE_ping() runs on gNBNGAPComponent return boolean {
		var UT_COMMON_CNF v_cnf;
		var GtpuMessage v_gtpu;
		var integer v_echoRequests := 0; // Conformant G-PDUs carrying an echo request of the UE
		var boolean v_conformant := true;
		timer t_ping := int2float(PX_UT_PING_COUNT * PX_UT_PING_TIMEOUT) + 30.0;

		if (PX_UT_PING_HOST == "") {
		@@ -898,15 +907,109 @@ module NGAP_Steps { // TODO FSCOM f_xxx_UE_SecurityMode to be mmoved into NAG_NG
		}
		repeat;
		}
		[PICS_USE_GTPU] N3_P.receive(mw_gtpu_any) -> value v_gtpu {
		fl_count_uplink_gpdu(v_gtpu, v_echoRequests, v_conformant);
		repeat;
		}
		[] t_ping.timeout {
		log("* " & __SCOPE__ & ": INFO: no ping result from the upper tester *");
		return false;
		}
		}
		log("* " & __SCOPE__ & ": INFO: ping ", PX_UT_PING_HOST, " result: ", v_cnf, " *");
		if (not PICS_USE_GTPU) {
		return v_cnf.Result;
		}
		// G-PDUs still in flight or queued when the result came
		t_ping.start(1.0);
		alt {
		[] N3_P.receive(mw_gtpu_any) -> value v_gtpu {
		fl_count_uplink_gpdu(v_gtpu, v_echoRequests, v_conformant);
		repeat;
		}
		[] t_ping.timeout {
		}
		}
		log("* " & __SCOPE__ & ": INFO: ", v_echoRequests, " echo request(s) of the UE received on N3 *");
		if (v_cnf.Result and v_conformant and (v_echoRequests == 0)) {
		log("* " & __SCOPE__ & ": FAIL: the UE sent echo requests, but the gNB forwarded none on N3 *");
		setverdict(fail, "no uplink user data forwarded by the gNB on N3");
		return false;
		}
		if (v_conformant and (v_echoRequests > 0)) {
		log("* " & __SCOPE__ & ": PASS: uplink user data forwarded by the gNB on N3 *");
		}
		return v_cnf.Result and v_conformant and (v_echoRequests > 0);
		} // End of function f_NGAP_gnb_UE_ping

		/**
		* @brief Check an uplink G-PDU (f_NGAP_gnb_check_uplink_gpdu) and update the counters of f_NGAP_gnb_UE_ping.
		* @param p_gtpu The received GTP-U message.
		* @param p_echoRequests Incremented if it carries an echo request of the UE.
		* @param p_conformant Set to false if its GTP-U encapsulation does not conform.
		*/
		function fl_count_uplink_gpdu(in GtpuMessage p_gtpu, inout integer p_echoRequests, inout boolean p_conformant) runs on gNBNGAPComponent {
		var boolean v_echoRequest;
		if (not f_NGAP_gnb_check_uplink_gpdu(p_gtpu, v_echoRequest)) {
		p_conformant := false;
		} else if (v_echoRequest) {
		p_echoRequests := p_echoRequests + 1;
		}
		} // End of function fl_count_uplink_gpdu

		/**
		* @brief Check an uplink G-PDU the gNB forwarded on N3 for the PDU session of the UE (TS 29.281, TS 38.415).
		* @details The gNB is responsible for the GTP-U encapsulation, which must conform: a G-PDU, to the uplink
		* tunnel of the PDU session (PX_GTP_TEID), with a PDU Session Container of type UL PDU SESSION
		* INFORMATION for the QoS flow PX_QOS_FLOW_IDENTIFIER (TS 38.415 clause 5.5.2.2). The verdict is
		* set to fail otherwise.
		* The T-PDU, the packet of the UE that the gNB forwards unchanged, is then examined: an IPv4 ICMP
		* echo request from PX_UT_PDU_ADDRESS_IPV4 to PX_UT_PING_HOST is reported in p_echoRequest; any
		* other packet is only logged.
		* @param p_gtpu The received GTP-U message.
		* @param p_echoRequest true if it carries an echo request of the ping of the UE.
		* @return false if the GTP-U encapsulation does not conform.
		*/
		function f_NGAP_gnb_check_uplink_gpdu(in GtpuMessage p_gtpu, out boolean p_echoRequest) runs on gNBNGAPComponent return boolean {
		var integer v_pduType;
		var integer v_qfi;
		var octetstring v_source;
		var octetstring v_destination;
		var integer v_protocol;
		var octetstring v_payload;

		p_echoRequest := false;
		if (p_gtpu.header.messageType != c_gtpuGPdu) {
		log("f_NGAP_gnb_check_uplink_gpdu: INFO: GTP-U message ", p_gtpu.header.messageType, " ignored: ", p_gtpu);
		return true;
		}
		if (p_gtpu.header.teid != PX_GTP_TEID) {
		log("* " & __SCOPE__ & ": FAIL: G-PDU to TEID ", p_gtpu.header.teid, ", expected ", PX_GTP_TEID, " *");
		setverdict(fail, "G-PDU to an unexpected TEID");
		return false;
		}
		if (not f_gtpu_getPduSessionContainer(p_gtpu, v_pduType, v_qfi)) {
		log("* " & __SCOPE__ & ": FAIL: G-PDU without PDU Session Container: ", p_gtpu.header, " *");
		setverdict(fail, "G-PDU without PDU Session Container");
		return false;
		}
		if ((v_pduType != c_pduSessionUlInformation) or (v_qfi != PX_QOS_FLOW_IDENTIFIER)) {
		log("*** " & __SCOPE__ & ": FAIL: PDU Session Container with PDU type ", v_pduType, " and QFI ", v_qfi,
		", expected ", c_pduSessionUlInformation, " (UL) and ", PX_QOS_FLOW_IDENTIFIER, " ***");
		setverdict(fail, "unexpected PDU Session Container");
		return false;
		}
		if (not f_ipv4_getHeader(p_gtpu.payload, v_source, v_destination, v_protocol, v_payload)) {
		log("f_NGAP_gnb_check_uplink_gpdu: INFO: T-PDU is not an IPv4 packet: ", p_gtpu.payload);
		return true;
		}
		p_echoRequest := (v_source == PX_UT_PDU_ADDRESS_IPV4) and (v_destination == f_ipv4_fromString(PX_UT_PING_HOST))
		and (v_protocol == 1) and (lengthof(v_payload) > 0) and (v_payload[0] == '08'O);
		log("f_NGAP_gnb_check_uplink_gpdu: G-PDU conforms, QFI ", v_qfi, ", IPv4 ", f_ipv4_toString(v_source), " -> ",
		f_ipv4_toString(v_destination), ", protocol ", v_protocol, ", echo request of the UE: ", p_echoRequest);
		return true;
		} // End of function f_NGAP_gnb_check_uplink_gpdu

		/**
		* @brief Leave the real UE in a known state at the end of a test: deregistered, in flight mode.
		* @details Unless PX_UT_DEREGISTER_TIMEOUT is 0.0: asks the upper tester to switch the modem to flight

ttcn/AtsNGAP/NGAP_TestConfiguration.ttcn

+4 −0

Changes for ttcn/AtsNGAP/NGAP_TestConfiguration.ttcn: 4 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -95,6 +95,10 @@ module NGAP_TestConfiguration {
		connect(p_NGAPComponent_gnb:syncPort, self:syncPort) ;
		//Map
		map(p_NGAPComponent_gnb:N2_gNBaMF_P, system:NGAP_gNB_1);
		if (PICS_USE_GTPU) {
		// The UDP port (2152) is bound here, until the component terminates
		map(p_NGAPComponent_gnb:N3_P, system:N3_gNB_1);
		}
		f_cf_Ut_Up(p_NGAPComponent_gnb);

		activate(a_mtc_shutdown());

ttcn/AtsNGAP/NGAP_TestSystem.ttcn

+2 −0

Changes for ttcn/AtsNGAP/NGAP_TestSystem.ttcn: 2 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@ module NGAP_TestSystem {

		// LibNGAP
		import from LibNGAP_Interface all;
		import from LibGtpu_Interface all;

		// UpperTester
		import from UpperTesterCommon all;
		@@ -33,6 +34,7 @@ module NGAP_TestSystem {

		port NGAPPort NGAP_AMF, NGAP_gNB_1, NGAP_gNB_2;
		port MTC_System_Ut utPort;
		port GtpuPort N3_gNB_1; // N3 user plane with the gNB under test (GTP-U), see PICS_USE_GTPU
		} // End of type TestAdapter

		} // End of group TestSystemInterfaces

ttcn/AtsNGAP/module.mk

+5 −4

Changes for ttcn/AtsNGAP/module.mk: 5 added lines, 4 removed lines.
Original line number	Diff line number	Diff line
		@@ -20,7 +20,7 @@ modules := \
		../LibCommon \
		../Lib3GPP \
		../UpperTester \
		../LibGtpv2 \
		../LibGtpu \
		../../titan-test-system-framework/ttcn/LibHelpers \
		../../titan-test-system-framework/ttcn/LibSecurity \
		../../titan-test-system-framework/ttcn/LibXsd \
		@@ -30,6 +30,7 @@ modules := \
		../../titan-test-system-framework/ccsrc/Protocols/IP \
		../../titan-test-system-framework/ccsrc/Protocols/Sctp \
		../../titan-test-system-framework/ccsrc/Protocols/Tcp \
		../../titan-test-system-framework/ccsrc/Protocols/UDP \
		../../titan-test-system-framework/ccsrc/Protocols/Xml \
		../../titan-test-system-framework/ccsrc/Framework \
		../../titan-test-system-framework/ccsrc/Helpers \
		@@ -39,15 +40,15 @@ modules := \
		../../ccsrc/Externals \
		../../ccsrc/Ports/LibNAS \
		../../ccsrc/Ports/LibNGAP \
		../../ccsrc/Ports/LibGtpv2 \
		../../ccsrc/Ports/LibGtpu \
		../../ccsrc/Ports/UpperTester \
		../../ccsrc/framework \
		../../ccsrc/Protocols/NGAP_layer \
		../../ccsrc/Protocols/NGAP \
		../../ccsrc/Protocols/NG_NAS \
		../../ccsrc/Protocols/FiveG_AKA \
		../../ccsrc/Protocols/Gtpv2_layer \
		../../ccsrc/Protocols/Gtpv2 \
		../../ccsrc/Protocols/Gtpu_layer \
		../../ccsrc/Protocols/Gtpu \
		../../ccsrc/Protocols/UT_layer \
		../../ccsrc/Protocols/UT \
		../modules/titan.TestPorts.Common_Components.Abstract_Socket