refactor: introduce UPNode as common interface for UPF and gNB nodes

go.mod

@@ -4,7 +4,7 @@ go 1.21
 
 require (
 	github.com/antihax/optional v1.0.0
-	github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d
+	github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2
 	github.com/davecgh/go-spew v1.1.1
 	github.com/free5gc/aper v1.0.5
 	github.com/free5gc/nas v1.1.3
@@ -60,6 +60,8 @@ require (
 	github.com/tim-ywliu/nested-logrus-formatter v1.3.2 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.11 // indirect
+	go4.org/intern v0.0.0-20211027215823-ae77deb06f29 // indirect
+	go4.org/unsafe/assume-no-moving-gc v0.0.0-20230525183740-e7c30c78aeb2 // indirect
 	golang.org/x/arch v0.3.0 // indirect
 	golang.org/x/crypto v0.21.0 // indirect
 	golang.org/x/net v0.23.0 // indirect
@@ -70,4 +72,5 @@ require (
 	google.golang.org/protobuf v1.33.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	inet.af/netaddr v0.0.0-20230525184311-b8eac61e914a // indirect
 )

go.sum

@@ -39,6 +39,8 @@ github.com/antonfisher/nested-logrus-formatter v1.3.1 h1:NFJIr+pzwv5QLHTPyKz9UME
 github.com/antonfisher/nested-logrus-formatter v1.3.1/go.mod h1:6WTfyWFkBc9+zyBaKIqRrg/KwMqBbodBjgbHjDz7zjA=
 github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d h1:Byv0BzEl3/e6D5CLfI0j/7hiIEtvGVFPCZ7Ei2oq8iQ=
 github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d/go.mod h1:WaHUgvxTVq04UNunO+XhnAqY/wQc+bxr74GqbsZ/Jqw=
+github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 h1:DklsrG3dyBCFEj5IhUbnKptjxatkF07cF2ak3yi77so=
+github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2/go.mod h1:WaHUgvxTVq04UNunO+XhnAqY/wQc+bxr74GqbsZ/Jqw=
 github.com/bytedance/sonic v1.5.0/go.mod h1:ED5hyg4y6t3/9Ku1R6dU/4KyJ48DZ4jPhfY1O2AihPM=
 github.com/bytedance/sonic v1.9.1 h1:6iJ6NqdoxCDr6mbY8h18oSO+cShGSMRGCEo7F2h0x8s=
 github.com/bytedance/sonic v1.9.1/go.mod h1:i736AoUSYt75HyZLoJW9ERYxcy6eaN6h4BZXU064P/U=
@@ -57,6 +59,7 @@ github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ3
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dvyukov/go-fuzz v0.0.0-20210103155950-6a8e9d1f2415/go.mod h1:11Gm+ccJnvAhCNLlf5+cS9KjtbaD5I5zaZpFMsTHWTw=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -235,13 +238,19 @@ github.com/urfave/cli v1.22.5/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtX
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.uber.org/mock v0.4.0 h1:VcM4ZOtdbR4f6VXfiOpwpVJDL6lCReaZ6mw31wqh7KU=
 go.uber.org/mock v0.4.0/go.mod h1:a6FSlNadKUHUa9IP5Vyt1zh4fC7uAwxMutEAscFbkZc=
+go4.org/intern v0.0.0-20211027215823-ae77deb06f29 h1:UXLjNohABv4S58tHmeuIZDO6e3mHpW2Dx33gaNt03LE=
+go4.org/intern v0.0.0-20211027215823-ae77deb06f29/go.mod h1:cS2ma+47FKrLPdXFpr7CuxiTW3eyJbWew4qx0qtQWDA=
+go4.org/unsafe/assume-no-moving-gc v0.0.0-20211027215541-db492cf91b37/go.mod h1:FftLjUGFEDu5k8lt0ddY+HcrH/qU/0qk+H8j9/nTl3E=
+go4.org/unsafe/assume-no-moving-gc v0.0.0-20230525183740-e7c30c78aeb2 h1:WJhcL4p+YeDxmZWg141nRm7XC8IDmhz7lk5GpadO1Sg=
+go4.org/unsafe/assume-no-moving-gc v0.0.0-20230525183740-e7c30c78aeb2/go.mod h1:FftLjUGFEDu5k8lt0ddY+HcrH/qU/0qk+H8j9/nTl3E=
 golang.org/x/arch v0.0.0-20210923205945-b76863e36670/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
 golang.org/x/arch v0.3.0 h1:02VY4/ZcO/gBOH6PUaoiptASxtXU10jazRCP865E97k=
 golang.org/x/arch v0.3.0/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
@@ -308,6 +317,7 @@ golang.org/x/net v0.0.0-20200520182314-0ba52f642ac2/go.mod h1:qpuaurCH72eLCgpAm/
 golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.23.0 h1:7EYJ93RZ9vYSZAIb2x3lnuvqO5zneoD6IvWjuhfxjTs=
 golang.org/x/net v0.23.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
@@ -325,6 +335,7 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -351,6 +362,8 @@ golang.org/x/sys v0.0.0-20200511232937-7e40ca221e25/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200515095857-1151b9dac4a9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200523222454-059865788121/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200803210538-64077c9b5642/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20220704084225-05e143d24a9e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
@@ -406,6 +419,7 @@ golang.org/x/tools v0.0.0-20200618134242-20370b0cb4b2/go.mod h1:EkVYQZoAsY45+roY
 golang.org/x/tools v0.0.0-20200729194436-6467de6f59a7/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20200804011535-6c149bb5ef0d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20200825202427-b303f430e36d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
+golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
@@ -507,6 +521,8 @@ honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWh
 honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
 honnef.co/go/tools v0.0.1-2020.1.3/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9vFzvIQ3k=
 honnef.co/go/tools v0.0.1-2020.1.4/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9vFzvIQ3k=
+inet.af/netaddr v0.0.0-20230525184311-b8eac61e914a h1:1XCVEdxrvL6c0TGOhecLuB7U9zYNdxZEjvOqJreKZiM=
+inet.af/netaddr v0.0.0-20230525184311-b8eac61e914a/go.mod h1:e83i32mAQOW1LAqEIweALsuK2Uw4mhQadA5r7b0Wobo=
 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=
 rsc.io/quote/v3 v3.1.0/go.mod h1:yEA65RcK8LyAZtP9Kv3t0HmxON59tX3rD+tICJqUlj0=

internal/context/context.go

@@ -176,26 +176,13 @@ func InitSmfContext(config *factory.Config) {
 		smfContext.ListenAddr = pfcp.ListenAddr
 		smfContext.ExternalAddr = pfcp.ExternalAddr
 
-		if ip := net.ParseIP(pfcp.NodeID); ip == nil {
-			smfContext.CPNodeID = pfcpType.NodeID{
-				NodeIdType: pfcpType.NodeIdTypeFqdn,
-				FQDN:       pfcp.NodeID,
-			}
-		} else {
-			ipv4 := ip.To4()
-			if ipv4 != nil {
-				smfContext.CPNodeID = pfcpType.NodeID{
-					NodeIdType: pfcpType.NodeIdTypeIpv4Address,
-					IP:         ipv4,
-				}
-			} else {
-				smfContext.CPNodeID = pfcpType.NodeID{
-					NodeIdType: pfcpType.NodeIdTypeIpv6Address,
-					IP:         ip,
-				}
-			}
+		nodeID, err := ConfigToNodeID(pfcp.NodeID)
+		if err != nil {
+			logger.InitLog.Fatalf("[InitSmfContext] cannot parse PFCP NodeID from config: %+v", err)
 		}
 
+		smfContext.CPNodeID = nodeID
+
 		smfContext.PfcpHeartbeatInterval = pfcp.HeartbeatInterval
 		var multipleOfInterval time.Duration = 5
 		if pfcp.AssocFailAlertInterval == 0 {
@@ -239,7 +226,7 @@ func InitSmfContext(config *factory.Config) {
 
 	smfContext.SupportedPDUSessionType = "IPv4"
 
-	smfContext.UserPlaneInformation = NewUserPlaneInformation(&configuration.UserPlaneInformation)
+	smfContext.UserPlaneInformation = NewUserPlaneInformation(configuration.UserPlaneInformation)
 
 	smfContext.ChargingIDGenerator = idgenerator.NewGenerator(1, math.MaxUint32)
 

internal/context/datapath.go

@@ -135,7 +135,7 @@ func (node *DataPathNode) ActivateUpLinkTunnel(smContext *SMContext) error {
 
 	destUPF := node.UPF
 	if node.UpLinkTunnel.PDR, err = destUPF.AddPDR(); err != nil {
-		logger.CtxLog.Errorln("In ActivateUpLinkTunnel UPF IP: ", node.UPF.NodeID.ResolveNodeIdToIp().String())
+		logger.CtxLog.Errorln("In ActivateUpLinkTunnel UPF IP: ", node.GetNodeIP())
 		logger.CtxLog.Errorln("Allocate PDR Error: ", err)
 		return fmt.Errorf("Add PDR failed: %s", err)
 	}
@@ -159,7 +159,7 @@ func (node *DataPathNode) ActivateDownLinkTunnel(smContext *SMContext) error {
 
 	destUPF := node.UPF
 	if node.DownLinkTunnel.PDR, err = destUPF.AddPDR(); err != nil {
-		logger.CtxLog.Errorln("In ActivateDownLinkTunnel UPF IP: ", node.UPF.NodeID.ResolveNodeIdToIp().String())
+		logger.CtxLog.Errorln("In ActivateDownLinkTunnel UPF IP: ", node.GetNodeIP())
 		logger.CtxLog.Errorln("Allocate PDR Error: ", err)
 		return fmt.Errorf("Add PDR failed: %s", err)
 	}
@@ -244,20 +244,12 @@ func (node *DataPathNode) DeactivateDownLinkTunnel(smContext *SMContext) {
 	}
 }
 
-func (node *DataPathNode) GetUPFID() (id string, err error) {
-	node_ip := node.GetNodeIP()
-	var exist bool
-
-	if id, exist = smfContext.UserPlaneInformation.UPFsIPtoID[node_ip]; !exist {
-		err = fmt.Errorf("UPNode IP %s doesn't exist in smfcfg.yaml", node_ip)
-		return "", err
-	}
-
-	return id, nil
+func (node *DataPathNode) GetUPFID() uuid.UUID {
+	return node.UPF.GetID()
 }
 
 func (node *DataPathNode) GetNodeIP() (ip string) {
-	ip = node.UPF.NodeID.ResolveNodeIdToIp().String()
+	ip = node.UPF.GetNodeIDString()
 	return
 }
 
@@ -319,17 +311,17 @@ func (dataPath *DataPath) String() string {
 	for curDPNode := firstDPNode; curDPNode != nil; curDPNode = curDPNode.Next() {
 		str += strconv.Itoa(index) + "th Node in the Path\n"
 		str += "Current UPF IP: " + curDPNode.GetNodeIP() + "\n"
-		str += "Current UPF ID: " + curDPNode.UPF.GetUPFID() + "\n"
+		str += "Current UPF ID: " + curDPNode.UPF.GetID().String() + "\n"
 		if curDPNode.Prev() != nil {
 			str += "Previous UPF IP: " + curDPNode.Prev().GetNodeIP() + "\n"
-			str += "Previous UPF ID: " + curDPNode.Prev().UPF.GetUPFID() + "\n"
+			str += "Previous UPF ID: " + curDPNode.Prev().UPF.GetID().String() + "\n"
 		} else {
 			str += "Previous UPF IP: None\n"
 		}
 
 		if curDPNode.Next() != nil {
 			str += "Next UPF IP: " + curDPNode.Next().GetNodeIP() + "\n"
-			str += "Next UPF ID: " + curDPNode.Next().UPF.GetUPFID() + "\n"
+			str += "Next UPF ID: " + curDPNode.Next().UPF.GetID().String() + "\n"
 		} else {
 			str += "Next UPF IP: None\n"
 		}
@@ -340,8 +332,8 @@ func (dataPath *DataPath) String() string {
 	return str
 }
 
-func getUrrIdKey(uuid string, urrId uint32) string {
-	return uuid + ":" + strconv.Itoa(int(urrId))
+func getUrrIdKey(uuid uuid.UUID, urrId uint32) string {
+	return uuid.String() + ":" + strconv.Itoa(int(urrId))
 }
 
 func GetUpfIdFromUrrIdKey(urrIdKey string) string {
@@ -352,7 +344,7 @@ func (node DataPathNode) addUrrToNode(smContext *SMContext, urrId uint32, isMeas
 	var urr *URR
 	var ok bool
 	var err error
-	currentUUID := node.UPF.UUID()
+	currentUUID := node.UPF.GetID()
 	id := getUrrIdKey(currentUUID, urrId)
 
 	if urr, ok = smContext.UrrUpfMap[id]; !ok {
@@ -412,7 +404,7 @@ func (dataPath *DataPath) ActivateTunnelAndPDR(smContext *SMContext, precedence
 	logger.PduSessLog.Traceln(dataPath.String())
 	// Activate Tunnels
 	for node := firstDPNode; node != nil; node = node.Next() {
-		logger.PduSessLog.Traceln("Current DP Node IP: ", node.UPF.NodeID.ResolveNodeIdToIp().String())
+		logger.PduSessLog.Traceln("Current DP Node IP: ", node.GetNodeIP())
 		if err := node.ActivateUpLinkTunnel(smContext); err != nil {
 			logger.CtxLog.Warnln(err)
 			return
@@ -438,7 +430,7 @@ func (dataPath *DataPath) ActivateTunnelAndPDR(smContext *SMContext, precedence
 	for curDataPathNode := firstDPNode; curDataPathNode != nil; curDataPathNode = curDataPathNode.Next() {
 		var defaultQER *QER
 		var ambrQER *QER
-		currentUUID := curDataPathNode.UPF.uuid
+		currentUUID := curDataPathNode.UPF.GetID()
 		if qerId, okCurrentId := smContext.AMBRQerMap[currentUUID]; !okCurrentId {
 			if newQER, err := curDataPathNode.UPF.AddQER(); err != nil {
 				logger.PduSessLog.Errorln("new QER failed")
@@ -644,7 +636,7 @@ func (dataPath *DataPath) ActivateTunnelAndPDR(smContext *SMContext, precedence
 
 			DLFAR := DLPDR.FAR
 
-			logger.PduSessLog.Traceln("Current DP Node IP: ", curDataPathNode.UPF.NodeID.ResolveNodeIdToIp().String())
+			logger.PduSessLog.Traceln("Current DP Node IP: ", curDataPathNode.GetNodeIP())
 			logger.PduSessLog.Traceln("Before DLPDR OuterHeaderCreation")
 			if nextDLDest := curDataPathNode.Prev(); nextDLDest != nil {
 				logger.PduSessLog.Traceln("In DLPDR OuterHeaderCreation")
@@ -768,7 +760,7 @@ func (p *DataPath) AddChargingRules(smContext *SMContext, chgLevel ChargingLevel
 			chgInfo := &ChargingInfo{
 				RatingGroup:   chgData.RatingGroup,
 				ChargingLevel: chgLevel,
-				UpfId:         node.UPF.UUID(),
+				UpfId:         node.UPF.GetID().String(),
 			}
 
 			urrId, err := smContext.UrrIDGenerator.Allocate()
@@ -777,7 +769,7 @@ func (p *DataPath) AddChargingRules(smContext *SMContext, chgLevel ChargingLevel
 				return
 			}
 
-			currentUUID := node.UPF.UUID()
+			currentUUID := node.UPF.GetID()
 			id := getUrrIdKey(currentUUID, uint32(urrId))
 
 			if oldURR, ok := smContext.UrrUpfMap[id]; !ok {
@@ -820,7 +812,7 @@ func (p *DataPath) AddChargingRules(smContext *SMContext, chgLevel ChargingLevel
 					if !isUrrExist(node.UpLinkTunnel.PDR.URR, urr) {
 						node.UpLinkTunnel.PDR.AppendURRs([]*URR{urr})
 						// nolint
-						nodeId, _ := node.GetUPFID()
+						nodeId := node.GetUPFID()
 						logger.PduSessLog.Tracef("UpLinkTunnel add URR for node %s %+v",
 							nodeId, node.UpLinkTunnel.PDR)
 					}
@@ -829,7 +821,7 @@ func (p *DataPath) AddChargingRules(smContext *SMContext, chgLevel ChargingLevel
 					if !isUrrExist(node.DownLinkTunnel.PDR.URR, urr) {
 						node.DownLinkTunnel.PDR.AppendURRs([]*URR{urr})
 						// nolint
-						nodeId, _ := node.GetUPFID()
+						nodeId := node.GetUPFID()
 						logger.PduSessLog.Tracef("DownLinkTunnel add URR for node %s %+v",
 							nodeId, node.DownLinkTunnel.PDR)
 					}
@@ -847,7 +839,7 @@ func (p *DataPath) AddQoS(smContext *SMContext, qfi uint8, qos *models.QosData)
 	for node := p.FirstDPNode; node != nil; node = node.Next() {
 		var qer *QER
 
-		currentUUID := node.UPF.GetUUID()
+		currentUUID := node.UPF.GetID()
 		id := getQosIdKey(currentUUID, qfi)
 
 		if qerId, ok := smContext.QerUpfMap[id]; !ok {

internal/context/gnb.go

@@ -0,0 +1,71 @@
+package context
+
+import (
+	"fmt"
+
+	"github.com/google/uuid"
+
+	"github.com/free5gc/smf/internal/logger"
+)
+
+// embeds the UPNode struct ("inheritance")
+// implements UPNodeInterface
+type GNB struct {
+	*UPNode
+}
+
+func (gNB *GNB) GetName() string {
+	return gNB.Name
+}
+
+func (gNB *GNB) GetID() uuid.UUID {
+	return gNB.ID
+}
+
+func (gNB *GNB) GetType() UPNodeType {
+	return gNB.Type
+}
+
+func (gNB *GNB) String() string {
+	str := "gNB {\n"
+	prefix := "  "
+	str += prefix + fmt.Sprintf("Name: %s\n", gNB.Name)
+	str += prefix + fmt.Sprintf("ID: %s\n", gNB.ID)
+	str += prefix + fmt.Sprintln("Links:")
+	for _, link := range gNB.Links {
+		str += prefix + fmt.Sprintf("-- %s: %s\n", link.GetName(), link.GetName())
+	}
+	str += "}"
+	return str
+}
+
+func (gNB *GNB) GetLinks() UPPath {
+	return gNB.Links
+}
+
+func (gNB *GNB) AddLink(link UPNodeInterface) bool {
+	for _, existingLink := range gNB.Links {
+		if link.GetName() == existingLink.GetName() {
+			logger.CfgLog.Warningf("UPLink [%s] <=> [%s] already exists, skip\n", existingLink.GetName(), link.GetName())
+			return false
+		}
+	}
+	gNB.Links = append(gNB.Links, link)
+	return true
+}
+
+func (gNB *GNB) RemoveLink(link UPNodeInterface) bool {
+	for i, existingLink := range gNB.Links {
+		if link.GetName() == existingLink.GetName() && existingLink.GetName() == link.GetName() {
+			logger.CfgLog.Warningf("Remove UPLink [%s] <=> [%s]\n", existingLink.GetName(), link.GetName())
+			gNB.Links = append(gNB.Links[:i], gNB.Links[i+1:]...)
+			return true
+		}
+	}
+	return false
+}
+
+func (gNB *GNB) RemoveLinkByIndex(index int) bool {
+	gNB.Links[index] = gNB.Links[len(gNB.Links)-1]
+	return true
+}

internal/context/pfcp_reports.go

@@ -15,7 +15,7 @@ func (smContext *SMContext) HandleReports(
 ) {
 	var usageReport UsageReport
 	upf := RetrieveUPFNodeByNodeID(nodeId)
-	upfId := upf.UUID()
+	upfId := upf.GetID()
 
 	for _, report := range usageReportRequest {
 		usageReport.UrrId = report.URRID.UrrIdValue