UE ip pool allocation by UPF

conf/upf.json

@@ -53,9 +53,11 @@
 
     "": "Control plane controller settings",
     "cpiface": {
-	"nb_dst_ip": "172.17.0.1",
-	"" : "nb_dst_ip: CPHostname",
-	"hostname": "spgwc"
+        "enable_ue_ip_alloc": false,
+        "ue_ip_pool": "10.250.0.0/16",
+        "nb_dst_ip": "172.17.0.1",
+        "" : "nb_dst_ip: CPHostname",
+	    "hostname": "spgwc"
     },
 
     "": "p4rtc interface settings",

pfcpiface/bess.go

@@ -278,6 +278,12 @@ func (b *bess) setUpfInfo(u *upf, conf *Conf) {
 		u.simInfo = simInfo
 	}
 
+	u.ippool_cidr = conf.CPIface.UeIPPool
+	log.Println("IP pool : ", u.ippool_cidr)
+	errin := u.ippool.init_pool(u.ippool_cidr)
+	if errin != nil {
+		log.Println("ip pool init failed")
+	}
 	u.accessIP = ParseIP(conf.AccessIface.IfName, "Access")
 	u.coreIP = ParseIP(conf.CoreIface.IfName, "Core")
 	if *n4SrcIPStr != "" {
@@ -299,7 +305,6 @@ func (b *bess) setUpfInfo(u *upf, conf *Conf) {
 		}
 	}
 	// get bess grpc client
-	var errin error
 	log.Println("bessIP ", *bessIP)
 
 	b.conn, errin = grpc.Dial(*bessIP, grpc.WithInsecure())

pfcpiface/go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/grpc-ecosystem/go-grpc-middleware v1.2.2
 	github.com/p4lang/p4runtime v1.3.0
 	github.com/prometheus/client_golang v1.9.0
-	github.com/wmnsk/go-pfcp v0.0.8
+	github.com/wmnsk/go-pfcp v0.0.9-0.20210129064645-e1b1f34ebd9f
 	google.golang.org/genproto v0.0.0-20200526211855-cb27e3aa2013
 	google.golang.org/grpc v1.35.0
 	google.golang.org/protobuf v1.25.0

pfcpiface/go.sum

@@ -288,8 +288,8 @@ github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5
 github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
 github.com/urfave/cli v1.22.1/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
-github.com/wmnsk/go-pfcp v0.0.8 h1:H/PDw2gvoYmXu3vltuIuJlckytUMpef4fAxl/ij2o64=
-github.com/wmnsk/go-pfcp v0.0.8/go.mod h1:Hwc6b/KmDF6tGa5hwhP5UGfKgwnL2CICFs3PgFz5cRE=
+github.com/wmnsk/go-pfcp v0.0.9-0.20210129064645-e1b1f34ebd9f h1:eof2jcYxj5zXKwR012IIeZ+odMCUMX/P+Oc163Ec6/s=
+github.com/wmnsk/go-pfcp v0.0.9-0.20210129064645-e1b1f34ebd9f/go.mod h1:Hwc6b/KmDF6tGa5hwhP5UGfKgwnL2CICFs3PgFz5cRE=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.etcd.io/etcd v0.0.0-20191023171146-3cf2f69b5738/go.mod h1:dnLIgRNXwCJa5e+c6mIZCrds/GIG4ncV9HhK5PX7jPg=

pfcpiface/ip_pool.go

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright(c) 2020 Intel Corporation
+
+package main
+
+import (
+	"errors"
+	"log"
+	"net"
+
+	"github.com/wmnsk/go-pfcp/ie"
+)
+
+type ip_pool struct {
+	free_pool []string
+}
+
+func needAllocIp(ueIPaddr *ie.UEIPAddressFields) bool {
+	if has2ndBit(ueIPaddr.Flags) && !has5thBit(ueIPaddr.Flags) {
+		return false
+	}
+	return true
+}
+
+func (ipp *ip_pool) deallocIPV4(element net.IP) {
+	ipp.free_pool = append(ipp.free_pool, element.String()) // Simply append to enqueue.
+	log.Println("Enqueued:", element.String())
+}
+
+func (ipp *ip_pool) allocIPV4() (net.IP, error) {
+	if len(ipp.free_pool) == 0 {
+		err := errors.New("ip pool empty")
+		return nil, err
+	}
+	element := ipp.free_pool[0] // The first element is the one to be dequeued.
+	log.Println("Dequeued:", element)
+	ipp.free_pool = ipp.free_pool[1:] // Slice off the element once it is dequeued.
+	ipVal := net.ParseIP(element).To4()
+	return ipVal, nil
+}
+
+func (ipp *ip_pool) init_pool(cidr string) error {
+	ip, ipnet, err := net.ParseCIDR(cidr)
+	if err != nil {
+		return err
+	}
+
+	for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); inc(ip) {
+		ipp.free_pool = append(ipp.free_pool, ip.String())
+	}
+	// remove network address and broadcast address
+
+	ipp.free_pool = ipp.free_pool[1 : len(ipp.free_pool)-1]
+	return nil
+}

pfcpiface/main.go

@@ -52,9 +52,11 @@ type SimModeInfo struct {
 
 // CPIfaceInfo : CPIface interface settings
 type CPIfaceInfo struct {
-	DestIP   string `json:"nb_dst_ip"`
-	SrcIP    string `json:"nb_src_ip"`
-	FQDNHost string `json:"hostname"`
+	EnableUeIPAlloc bool   `json:"enable_ue_ip_alloc"`
+	DestIP          string `json:"nb_dst_ip"`
+	SrcIP           string `json:"nb_src_ip"`
+	FQDNHost        string `json:"hostname"`
+	UeIPPool        string `json:"ue_ip_pool"`
 }
 
 // IfaceType : Gateway interface struct
@@ -139,11 +141,12 @@ func main() {
 	}
 
 	upf := &upf{
-		accessIface: conf.AccessIface.IfName,
-		coreIface:   conf.CoreIface.IfName,
-		fqdnHost:    fqdnh,
-		maxSessions: conf.MaxSessions,
-		intf:        intf,
+		accessIface:     conf.AccessIface.IfName,
+		coreIface:       conf.CoreIface.IfName,
+		fqdnHost:        fqdnh,
+		maxSessions:     conf.MaxSessions,
+		intf:            intf,
+		enableUeIPAlloc: conf.CPIface.EnableUeIPAlloc,
 	}
 
 	upf.setUpfInfo(&conf)

pfcpiface/messages.go

@@ -57,15 +57,23 @@ func (pc *PFCPConn) handleAssociationSetupRequest(upf *upf, msg message.Message,
 
 	// Build response message
 	// Timestamp shouldn't be the time message is sent in the real deployment but anyway :D
-	asres, err := message.NewAssociationSetupResponse(asreq.SequenceNumber,
+	asresmsg := message.NewAssociationSetupResponse(asreq.SequenceNumber,
 		ie.NewRecoveryTimeStamp(time.Now()),
 		ie.NewNodeID(sourceIP, "", ""), /* node id (IPv4) */
 		ie.NewCause(cause),             /* accept it blindly for the time being */
 		// 0x41 = Spare (0) | Assoc Src Inst (1) | Assoc Net Inst (0) | Tied Range (000) | IPV6 (0) | IPV4 (1)
 		//      = 01000001
 		ie.NewUserPlaneIPResourceInformation(0x41, 0, upf.accessIP.String(), "", "", ie.SrcInterfaceAccess),
 		// ie.NewUserPlaneIPResourceInformation(0x41, 0, coreIP, "", "", ie.SrcInterfaceCore),
-	).Marshal() /* userplane ip resource info */
+	) /* userplane ip resource info */
+
+	if upf.enableUeIPAlloc {
+		features := make([]uint8, 4)
+		setUeipFeature(features...)
+		asresmsg.UPFunctionFeatures =
+			ie.NewUPFunctionFeatures(features...)
+	}
+	asres, err := asresmsg.Marshal()
 	if err != nil {
 		log.Fatalln("Unable to create association setup response", err)
 	}
@@ -247,7 +255,7 @@ func (pc *PFCPConn) handleSessionEstablishmentRequest(upf *upf, msg message.Mess
 	session := pc.mgr.sessions[localSEID]
 	for _, cPDR := range sereq.CreatePDR {
 		var p pdr
-		if err := p.parsePDR(cPDR, session.localSEID, pc.mgr.appPFDs); err != nil {
+		if err := p.parsePDR(cPDR, session.localSEID, pc.mgr.appPFDs, upf); err != nil {
 			return sendError(err)
 		}
 		p.fseidIP = fseidIP
@@ -270,15 +278,18 @@ func (pc *PFCPConn) handleSessionEstablishmentRequest(upf *upf, msg message.Mess
 	}
 
 	// Build response message
-	seres, err := message.NewSessionEstablishmentResponse(0, /* MO?? <-- what's this */
+	seresMsg := message.NewSessionEstablishmentResponse(0, /* MO?? <-- what's this */
 		0,                                    /* FO <-- what's this? */
 		session.remoteSEID,                   /* seid */
 		sereq.SequenceNumber,                 /* seq # */
 		0,                                    /* priority */
 		ie.NewNodeID(sourceIP, "", ""),       /* node id (IPv4) */
 		ie.NewCause(ie.CauseRequestAccepted), /* accept it blindly for the time being */
 		ie.NewFSEID(session.localSEID, net.ParseIP(sourceIP), nil, nil),
-	).Marshal()
+	)
+
+	addPdrInfo(seresMsg, &session)
+	seres, err := seresMsg.Marshal()
 	if err != nil {
 		log.Fatalln("Unable to create session establishment response", err)
 	}
@@ -336,7 +347,7 @@ func (pc *PFCPConn) handleSessionModificationRequest(upf *upf, msg message.Messa
 	addFARs := make([]far, 0, MaxItems)
 	for _, cPDR := range smreq.CreatePDR {
 		var p pdr
-		if err := p.parsePDR(cPDR, localSEID, pc.mgr.appPFDs); err != nil {
+		if err := p.parsePDR(cPDR, localSEID, pc.mgr.appPFDs, upf); err != nil {
 			return sendError(err)
 		}
 		p.fseidIP = fseidIP
@@ -357,7 +368,7 @@ func (pc *PFCPConn) handleSessionModificationRequest(upf *upf, msg message.Messa
 	for _, uPDR := range smreq.UpdatePDR {
 		var p pdr
 		var err error
-		if err = p.parsePDR(uPDR, localSEID, pc.mgr.appPFDs); err != nil {
+		if err = p.parsePDR(uPDR, localSEID, pc.mgr.appPFDs, upf); err != nil {
 			return sendError(err)
 		}
 		err = session.UpdatePDR(p)
@@ -477,6 +488,7 @@ func (pc *PFCPConn) handleSessionDeletionRequest(upf *upf, msg message.Message,
 		return sendError(errors.New("Write to FastPath failed"))
 	}
 
+	releaseAllocatedIPs(upf, &session)
 	/* delete sessionRecord */
 	delete(pc.mgr.sessions, localSEID)
 

pfcpiface/parse-pdr.go

@@ -29,13 +29,14 @@ type pdr struct {
 	dstPortMask      uint16
 	protoMask        uint8
 
-	precedence uint32
-	pdrID      uint32
-	fseID      uint32
-	fseidIP    uint32
-	ctrID      uint32
-	farID      uint32
-	needDecap  uint8
+	precedence  uint32
+	pdrID       uint32
+	fseID       uint32
+	fseidIP     uint32
+	ctrID       uint32
+	farID       uint32
+	needDecap   uint8
+	allocIpFlag bool
 }
 
 func (p *pdr) printPDR() {
@@ -62,10 +63,11 @@ func (p *pdr) printPDR() {
 	log.Println("ctrID:", p.ctrID)
 	log.Println("farID:", p.farID)
 	log.Println("needDecap:", p.needDecap)
+	log.Println("allocIpFlag:", p.allocIpFlag)
 	log.Println("--------------------------------------------")
 }
 
-func (p *pdr) parsePDI(pdiIEs []*ie.IE, appPFDs map[string]appPFD) error {
+func (p *pdr) parsePDI(pdiIEs []*ie.IE, appPFDs map[string]appPFD, upf *upf) error {
 	var ueIP4 net.IP
 
 	for _, pdiIE := range pdiIEs {
@@ -77,7 +79,20 @@ func (p *pdr) parsePDI(pdiIEs []*ie.IE, appPFDs map[string]appPFD) error {
 				continue
 			}
 
-			ueIP4 = ueIPaddr.IPv4Address
+			if needAllocIp(ueIPaddr) {
+				/* alloc IPV6 if CHV6 is enabled : TBD */
+				log.Println("UPF should alloc UE IP. CHV4 flag set")
+				ueIP4, err = upf.ippool.allocIPV4()
+				if err != nil {
+					log.Println("failed to allocate UE IP")
+					return err
+				}
+				p.allocIpFlag = true
+				log.Println("ueipv4 : ", ueIP4.String())
+			} else {
+				log.Println("CP has allocated UE IP.")
+				ueIP4 = ueIPaddr.IPv4Address
+			}
 		case ie.SourceInterface:
 			srcIface, err := pdiIE.SourceInterface()
 			if err != nil {
@@ -212,7 +227,7 @@ func (p *pdr) parsePDI(pdiIEs []*ie.IE, appPFDs map[string]appPFD) error {
 	return nil
 }
 
-func (p *pdr) parsePDR(ie1 *ie.IE, seid uint64, appPFDs map[string]appPFD) error {
+func (p *pdr) parsePDR(ie1 *ie.IE, seid uint64, appPFDs map[string]appPFD, upf *upf) error {
 	/* reset outerHeaderRemoval to begin with */
 	outerHeaderRemoval := uint8(0)
 
@@ -239,7 +254,7 @@ func (p *pdr) parsePDR(ie1 *ie.IE, seid uint64, appPFDs map[string]appPFD) error
 		outerHeaderRemoval = 1
 	}
 
-	err = p.parsePDI(pdi, appPFDs)
+	err = p.parsePDI(pdi, appPFDs, upf)
 	if err != nil && err != errBadFilterDesc {
 		return err
 	}

pfcpiface/session-pdr.go

@@ -5,8 +5,43 @@ package main
 
 import (
 	"errors"
+	"github.com/wmnsk/go-pfcp/ie"
+	"github.com/wmnsk/go-pfcp/message"
+	"log"
+	"net"
 )
 
+// Release allocated IPs
+func releaseAllocatedIPs(upf *upf, session *PFCPSession) {
+	log.Println("release allocated IPs")
+	for _, pdr := range session.pdrs {
+		if (pdr.allocIpFlag) && (pdr.srcIface == core) {
+			log.Println("pdrID : ", pdr.pdrID)
+			var ueIP net.IP = int2ip(pdr.dstIP)
+			log.Println("ueIP : ", ueIP.String())
+			upf.ippool.deallocIPV4(ueIP)
+		}
+	}
+}
+
+func addPdrInfo(msg *message.SessionEstablishmentResponse,
+	session *PFCPSession) {
+	log.Println("Add PDRs with UPF alloc IPs to Establishment response")
+	for _, pdr := range session.pdrs {
+		if (pdr.allocIpFlag) && (pdr.srcIface == core) {
+			log.Println("pdrID : ", pdr.pdrID)
+			var flags uint8 = 0x02
+			var ueIP net.IP = int2ip(pdr.dstIP)
+			log.Println("ueIP : ", ueIP.String())
+			msg.CreatedPDR = append(msg.CreatedPDR,
+				ie.NewCreatedPDR(
+					ie.NewPDRID(uint16(pdr.pdrID)),
+					ie.NewUEIPAddress(flags, ueIP.String(), "", 0, 0),
+				))
+		}
+	}
+}
+
 // CreatePDR appends pdr to existing list of PDRs in the session
 func (s *PFCPSession) CreatePDR(p pdr) {
 	s.pdrs = append(s.pdrs, p)

pfcpiface/upf.go

@@ -8,15 +8,18 @@ import (
 )
 
 type upf struct {
-	accessIface string
-	coreIface   string
-	accessIP    net.IP
-	coreIP      net.IP
-	n4SrcIP     net.IP
-	fqdnHost    string
-	maxSessions uint32
-	simInfo     *SimModeInfo
-	intf        fastPath
+	enableUeIPAlloc bool
+	accessIface     string
+	coreIface       string
+	ippool_cidr     string
+	accessIP        net.IP
+	coreIP          net.IP
+	n4SrcIP         net.IP
+	fqdnHost        string
+	maxSessions     uint32
+	simInfo         *SimModeInfo
+	intf            fastPath
+	ippool          ip_pool
 }
 
 // to be replaced with go-pfcp structs