Add support for NGAP Handover

Signed-off-by: Valentin <[email protected]>

cmd/packetrusher.go

@@ -89,7 +89,8 @@ func main() {
 					&cli.IntFlag{Name: "number-of-ues", Value: 1, Aliases: []string{"n"}},
 					&cli.IntFlag{Name: "timeBetweenRegistration", Value: 500, Aliases: []string{"tr"}, Usage: "The time in ms, between UE registration."},
 					&cli.IntFlag{Name: "timeBeforeDeregistration", Value: 0, Aliases: []string{"td"}, Usage: "The time in ms, before a UE deregisters once it has been registered. 0 to disable auto-deregistration."},
-					&cli.IntFlag{Name: "timeBeforeHandover", Value: 0, Aliases: []string{"th"}, Usage: "The time in ms, before triggering a UE handover. 0 to disable handover. This requires at least two gNodeB, eg: two N2/N3 IPs."},
+					&cli.IntFlag{Name: "timeBeforeNgapHandover", Value: 0, Aliases: []string{"ngh"}, Usage: "The time in ms, before triggering a UE handover using NGAP Handover. 0 to disable handover. This requires at least two gNodeB, eg: two N2/N3 IPs."},
+					&cli.IntFlag{Name: "timeBeforeXnHandover", Value: 0, Aliases: []string{"xnh"}, Usage: "The time in ms, before triggering a UE handover using Xn Handover. 0 to disable handover. This requires at least two gNodeB, eg: two N2/N3 IPs."},
 					&cli.IntFlag{Name: "numPduSessions", Value: 1, Aliases: []string{"nPdu"}, Usage: "The number of PDU Sessions to create"},
 					&cli.BoolFlag{Name: "loop", Aliases: []string{"l"}, Usage: "Enable the creation of the GTP-U tunnel interface."},
 					&cli.BoolFlag{Name: "tunnel", Aliases: []string{"t"}, Usage: "Enable the creation of the GTP-U tunnel interface."},
@@ -120,7 +121,7 @@ func main() {
 						pcap.CaptureTraffic(c.Path("pcap"))
 					}
 
-					templates.TestMultiUesInQueue(numUes, c.Bool("tunnel"), c.Bool("dedicatedGnb"), c.Bool("loop"), c.Int("timeBetweenRegistration"), c.Int("timeBeforeDeregistration"), c.Int("timeBeforeHandover"), c.Int("numPduSessions"))
+					templates.TestMultiUesInQueue(numUes, c.Bool("tunnel"), c.Bool("dedicatedGnb"), c.Bool("loop"), c.Int("timeBetweenRegistration"), c.Int("timeBeforeDeregistration"), c.Int("timeBeforeNgapHandover"), c.Int("timeBeforeXnHandover"), c.Int("numPduSessions"))
 
 					return nil
 				},

internal/common/tools/tools.go

@@ -103,7 +103,8 @@ type UESimulationConfig struct {
 	Cfg                      config.Config
 	ScenarioChan             chan procedures.UeTesterMessage
 	TimeBeforeDeregistration int
-	TimeBeforeHandover       int
+	TimeBeforeNgapHandover   int
+	TimeBeforeXnHandover     int
 	NumPduSessions           int
 }
 
@@ -113,7 +114,9 @@ func SimulateSingleUE(simConfig UESimulationConfig, wg *sync.WaitGroup) {
 	ueCfg.Ue.Msin = IncrementMsin(simConfig.UeId, simConfig.Cfg.Ue.Msin)
 	log.Info("[TESTER] TESTING REGISTRATION USING IMSI ", ueCfg.Ue.Msin, " UE")
 
-	gnbId := gnbIdGenerator(simConfig.UeId%numGnb, ueCfg.GNodeB.PlmnList.GnbId)
+	gnbIdGen := func(index int) string {
+		return gnbIdGenerator((simConfig.UeId+index)%numGnb, ueCfg.GNodeB.PlmnList.GnbId)
+	}
 
 	// Launch a coroutine to handle UE's individual scenario
 	go func(scenarioChan chan procedures.UeTesterMessage, ueId int) {
@@ -123,7 +126,7 @@ func SimulateSingleUE(simConfig UESimulationConfig, wg *sync.WaitGroup) {
 
 		// Create a new UE coroutine
 		// ue.NewUE returns context of the new UE
-		ueTx := ue.NewUE(ueCfg, ueId, ueRx, simConfig.Gnbs[gnbId], wg)
+		ueTx := ue.NewUE(ueCfg, ueId, ueRx, simConfig.Gnbs[gnbIdGen(0)], wg)
 
 		// We tell the UE to perform a registration
 		ueRx <- procedures.UeTesterMessage{Type: procedures.Registration}
@@ -132,11 +135,19 @@ func SimulateSingleUE(simConfig UESimulationConfig, wg *sync.WaitGroup) {
 		if simConfig.TimeBeforeDeregistration != 0 {
 			deregistrationChannel = time.After(time.Duration(simConfig.TimeBeforeDeregistration) * time.Millisecond)
 		}
-		var handoverChannel <-chan time.Time = nil
-		if simConfig.TimeBeforeHandover != 0 {
-			handoverChannel = time.After(time.Duration(simConfig.TimeBeforeHandover) * time.Millisecond)
+
+		nextHandoverId := 0
+		var ngapHandoverChannel <-chan time.Time = nil
+		if simConfig.TimeBeforeNgapHandover != 0 {
+			ngapHandoverChannel = time.After(time.Duration(simConfig.TimeBeforeNgapHandover) * time.Millisecond)
+		}
+		var xnHandoverChannel <-chan time.Time = nil
+		if simConfig.TimeBeforeXnHandover != 0 {
+			xnHandoverChannel = time.After(time.Duration(simConfig.TimeBeforeXnHandover) * time.Millisecond)
 		}
 
+		log.Error(simConfig.TimeBeforeNgapHandover)
+		log.Error(simConfig.TimeBeforeXnHandover)
 		loop := true
 		state := ueCtx.MM5G_NULL
 		for loop {
@@ -146,8 +157,12 @@ func SimulateSingleUE(simConfig UESimulationConfig, wg *sync.WaitGroup) {
 					ueRx <- procedures.UeTesterMessage{Type: procedures.Terminate}
 					ueRx = nil
 				}
-			case <-handoverChannel:
-				trigger.TriggerHandover(simConfig.Gnbs[gnbId], simConfig.Gnbs[gnbIdGenerator((ueId+1)%numGnb, ueCfg.GNodeB.PlmnList.GnbId)], int64(ueId))
+			case <-ngapHandoverChannel:
+				trigger.TriggerNgapHandover(simConfig.Gnbs[gnbIdGen(nextHandoverId)], simConfig.Gnbs[gnbIdGen(nextHandoverId+1)], int64(ueId))
+				nextHandoverId++
+			case <-xnHandoverChannel:
+				trigger.TriggerXnHandover(simConfig.Gnbs[gnbIdGen(nextHandoverId)], simConfig.Gnbs[gnbIdGen(nextHandoverId+1)], int64(ueId))
+				nextHandoverId++
 			case msg := <-scenarioChan:
 				if ueRx != nil {
 					ueRx <- msg

internal/control_test_engine/gnb/context/context.go

@@ -9,6 +9,10 @@ import (
 	"fmt"
 	"sync"
 
+	"github.com/free5gc/aper"
+	"github.com/free5gc/ngap/ngapConvert"
+	"github.com/free5gc/ngap/ngapType"
+	"github.com/free5gc/openapi/models"
 	"github.com/ishidawataru/sctp"
 	log "github.com/sirupsen/logrus"
 	gtpv1 "github.com/wmnsk/go-gtp/gtpv1"
@@ -99,7 +103,9 @@ func (gnb *GNBContext) NewGnBUe(gnbTx chan UEMessage, gnbRx chan UEMessage, prUe
 
 	// store UE in the UE Pool of GNB.
 	gnb.uePool.Store(ranId, ue)
-	gnb.prUePool.Store(prUeId, ue)
+	if prUeId != 0 {
+		gnb.prUePool.Store(prUeId, ue)
+	}
 
 	// select AMF with Capacity is more than 0.
 	amf := gnb.selectAmFByActive()
@@ -399,6 +405,22 @@ func (gnb *GNBContext) GetSliceInBytes() ([]byte, []byte) {
 	return sstBytes, nil
 }
 
+func (gnb *GNBContext) GetPLMNIdentity() ngapType.PLMNIdentity {
+	return ngapConvert.PlmnIdToNgap(models.PlmnId{Mcc: gnb.controlInfo.mcc, Mnc: gnb.controlInfo.mnc})
+}
+
+func (gnb *GNBContext) GetNRCellIdentity() ngapType.NRCellIdentity {
+	nci := gnb.GetGnbIdInBytes()
+	var slice = make([]byte, 2)
+
+	return ngapType.NRCellIdentity{
+		Value: aper.BitString{
+			Bytes:     append(nci, slice...),
+			BitLength: 36,
+		},
+	}
+}
+
 func (gnb *GNBContext) GetMccAndMnc() (string, string) {
 	return gnb.controlInfo.mcc, gnb.controlInfo.mnc
 }

internal/control_test_engine/gnb/context/msg.go

@@ -16,4 +16,5 @@ type UEMessage struct {
 	Mcc              string
 	Mnc              string
 	UEContext        *GNBUe
+	IsHandover       bool
 }

internal/control_test_engine/gnb/context/ue.go

@@ -29,6 +29,7 @@ type GNBUe struct {
 	pRueId         int64 // PacketRusher unique UE ID
 	context        Context
 	lock           sync.Mutex
+	newGnb         *GNBContext
 }
 
 type Context struct {
@@ -204,6 +205,14 @@ func (ue *GNBUe) SetStateDown() {
 	ue.state = Down
 }
 
+func (ue *GNBUe) SetHandoverGnodeB(gnb *GNBContext) {
+	ue.newGnb = gnb
+}
+
+func (ue *GNBUe) GetHandoverGnodeB() *GNBContext {
+	return ue.newGnb
+}
+
 func (ue *GNBUe) GetGnbRx() chan UEMessage {
 	return ue.gnbRx
 }

internal/control_test_engine/gnb/nas/service/service.go

@@ -1,12 +1,14 @@
 /**
  * SPDX-License-Identifier: Apache-2.0
  * © Copyright 2023 Hewlett Packard Enterprise Development LP
+ * © Copyright 2023 Valentin D'Emmanuele
  */
 package service
 
 import (
 	"my5G-RANTester/internal/control_test_engine/gnb/context"
 	"my5G-RANTester/internal/control_test_engine/gnb/nas"
+	"my5G-RANTester/internal/control_test_engine/gnb/nas/message/sender"
 	"my5G-RANTester/internal/control_test_engine/gnb/ngap/trigger"
 
 	log "github.com/sirupsen/logrus"
@@ -29,17 +31,36 @@ func gnbListen(gnb *context.GNBContext) {
 		// store UE connection
 		// select AMF and get sctp association
 		// make a tun interface
-		ue := gnb.NewGnBUe(message.GNBTx, message.GNBRx, message.PrUeId)
-		if message.UEContext == nil {
-			log.Info("[GNB] Received incoming connection from new UE")
-			mcc, mnc := gnb.GetMccAndMnc()
-			message.GNBTx <- context.UEMessage{Mcc: mcc, Mnc: mnc}
-			ue.SetPduSessions(message.GNBPduSessions)
-		} else {
-			log.Info("[GNB] Received incoming handover for UE from another gNodeB")
+		ue, _ := gnb.GetGnbUeByPrUeId(message.PrUeId)
+		if ue != nil && message.IsHandover {
+			// We already have a context for this UE since it was sent to us by the AMF from a NGAP Handover
+			// Notify the AMF that the UE has succesfully been handed over to US
+			ue.SetGnbRx(message.GNBRx)
+			ue.SetGnbTx(message.GNBTx)
+
+			// We enable the new PDU Session handed over to us
+			msg := context.UEMessage{GNBPduSessions: ue.GetPduSessions(), GnbIp: gnb.GetN3GnbIp()}
+			sender.SendMessageToUe(ue, msg)
+
 			ue.SetStateReady()
-			ue.CopyFromPreviousContext(message.UEContext)
-			trigger.SendPathSwitchRequest(gnb, ue)
+
+			trigger.SendHandoverNotify(gnb, ue)
+		} else {
+			ue = gnb.NewGnBUe(message.GNBTx, message.GNBRx, message.PrUeId)
+			if message.UEContext != nil && message.IsHandover {
+				// Xn Handover
+				log.Info("[GNB] Received incoming handover for UE from another gNodeB")
+				ue.SetStateReady()
+				ue.CopyFromPreviousContext(message.UEContext)
+				trigger.SendPathSwitchRequest(gnb, ue)
+
+			} else {
+				// Usual first UE connection to a gNodeB
+				log.Info("[GNB] Received incoming connection from new UE")
+				mcc, mnc := gnb.GetMccAndMnc()
+				message.GNBTx <- context.UEMessage{Mcc: mcc, Mnc: mnc}
+				ue.SetPduSessions(message.GNBPduSessions)
+			}
 		}
 
 		if ue == nil {

internal/control_test_engine/gnb/ngap/dispatcher.go

@@ -66,6 +66,11 @@ func Dispatch(amf *context.GNBAmf, gnb *context.GNBContext, message []byte) {
 			log.Info("[GNB][NGAP] Receive AMF Configuration Update")
 			handler.HandlerAmfConfigurationUpdate(amf, gnb, ngapMsg)
 
+		case ngapType.ProcedureCodeHandoverResourceAllocation:
+			// handler NGAP Handover REquest
+			log.Info("[GNB][NGAP] Receive Handover Request")
+			handler.HandlerHandoverRequest(amf, gnb, ngapMsg)
+
 		case ngapType.ProcedureCodeErrorIndication:
 			// handler Error Indicator
 			log.Error("[GNB][NGAP] Receive Error Indication")
@@ -89,6 +94,11 @@ func Dispatch(amf *context.GNBAmf, gnb *context.GNBContext, message []byte) {
 			log.Info("[GNB][NGAP] Receive PathSwitchRequestAcknowledge")
 			handler.HandlerPathSwitchRequestAcknowledge(gnb, ngapMsg)
 
+		case ngapType.ProcedureCodeHandoverPreparation:
+			// handler NGAP AMF Handover Command
+			log.Info("[GNB][NGAP] Receive Handover Command")
+			handler.HandlerHandoverCommand(amf, gnb, ngapMsg)
+
 		default:
 			log.Info("[GNB][NGAP] Received unknown NGAP message")
 		}