Add RAN Areas

config/config.yaml

@@ -8,11 +8,29 @@ slices:
   nextmn-lite:
     pool: "10.0.0.0/24"
     upfs:
-      - node-id: "203.0.113.2" # only the first upf is used for now
+      - node-id: "203.0.113.2" # srgw1
         interfaces:
           - type: "N3"
             addr: "198.51.100.11"
+      - node-id: "203.0.113.3" # srgw2
+        interfaces:
+          - type: "N3"
+            addr: "198.51.100.12"
 
+areas: # RAN areas
+  area1:
+    gnbs: # list of gnbs in the area
+      - "http://192.0.2.2:8080" # gnb1
+      - "http://192.0.2.4.8080" # gnb2
+    paths: # define one path per slice
+      nextmn-lite:
+        - "203.0.113.2" # srgw1
+  area2:
+    gnbs:
+      - "http://192.0.2.5:8080" # gnb3
+    paths:
+      nextmn-lite:
+        - "203.0.113.3" # srgw2
 
 logger:
   level: "trace"

go.mod

@@ -16,7 +16,7 @@ require (
 
 require (
 	github.com/bytedance/sonic v1.12.7 // indirect
-	github.com/bytedance/sonic/loader v0.2.2 // indirect
+	github.com/bytedance/sonic/loader v0.2.3 // indirect
 	github.com/cloudwego/base64x v0.1.4 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.6 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.8 // indirect

go.sum

@@ -5,6 +5,8 @@ github.com/bytedance/sonic v1.12.7/go.mod h1:tnbal4mxOMju17EGfknm2XyYcpyCnIROYOE
 github.com/bytedance/sonic/loader v0.1.1/go.mod h1:ncP89zfokxS5LZrJxl5z0UJcsk4M4yY2JpfqGeCtNLU=
 github.com/bytedance/sonic/loader v0.2.2 h1:jxAJuN9fOot/cyz5Q6dUuMJF5OqQ6+5GfA8FjjQ0R4o=
 github.com/bytedance/sonic/loader v0.2.2/go.mod h1:N8A3vUdtUebEY2/VQC0MyhYeKUFosQU6FxH2JmUe6VI=
+github.com/bytedance/sonic/loader v0.2.3 h1:yctD0Q3v2NOGfSWPLPvG2ggA2kV6TS6s4wioyEqssH0=
+github.com/bytedance/sonic/loader v0.2.3/go.mod h1:N8A3vUdtUebEY2/VQC0MyhYeKUFosQU6FxH2JmUe6VI=
 github.com/cloudwego/base64x v0.1.4 h1:jwCgWpFanWmN8xoIUHa2rtzmkd5J2plF/dnLS6Xd/0Y=
 github.com/cloudwego/base64x v0.1.4/go.mod h1:0zlkT4Wn5C6NdauXdJRhSKRlJvmclQ1hhJgA0rcu/8w=
 github.com/cloudwego/iasm v0.2.0/go.mod h1:8rXZaNYT2n95jn+zTI1sDr+IgcD2GVs0nlbbQPiEFhY=

internal/amf/handover_notify.go

@@ -25,6 +25,7 @@ func (amf *Amf) HandoverNotify(c *gin.Context) {
 	logrus.WithFields(logrus.Fields{
 		"ue":         m.UeCtrl.String(),
 		"gnb-target": m.TargetGnb.String(),
+		"gbn-source": m.SourceGnb.String(),
 	}).Info("New Handover Confirm")
 	go amf.HandleHandoverNotify(m)
 	c.JSON(http.StatusAccepted, jsonapi.Message{Message: "please refer to logs for more information"})
@@ -40,11 +41,12 @@ func (amf *Amf) HandleHandoverNotify(m n1n2.HandoverNotify) {
 	ctx := amf.Context()
 	for _, session := range m.Sessions {
 		// Note: for the moment, we are only doing direct forwarding (step 2)
-		if err := amf.smf.UpdateSessionDownlinkContext(ctx, m.UeCtrl, session.Addr, session.Dnn); err != nil {
+		if err := amf.smf.UpdateSessionDownlinkContext(ctx, m.UeCtrl, session.Addr, session.Dnn, m.SourceGnb); err != nil {
 			logrus.WithError(err).WithFields(logrus.Fields{
 				"ue":          m.UeCtrl.String(),
 				"pdu-session": session.Addr,
 				"dnn":         session.Dnn,
+				"gnb-source":  m.SourceGnb,
 			}).Error("Handover Notify: could not update session downlink path")
 		}
 

internal/amf/n2_establishment_response.go

@@ -28,7 +28,7 @@ func (amf *Amf) N2EstablishmentResponse(c *gin.Context) {
 
 func (amf *Amf) HandleN2EstablishmentResponse(ps n1n2.N2PduSessionRespMsg) {
 	ctx := amf.Context()
-	pduSession, err := amf.smf.CreateSessionDownlinkContext(ctx, ps.UeInfo.Header.Ue, ps.UeInfo.Addr, ps.UeInfo.Header.Dnn, ps.DownlinkFteid.Addr, ps.DownlinkFteid.Teid)
+	pduSession, err := amf.smf.CreateSessionDownlinkContext(ctx, ps.UeInfo.Header.Ue, ps.UeInfo.Addr, ps.UeInfo.Header.Dnn, ps.UeInfo.Header.Gnb, ps.DownlinkFteid)
 	if err != nil {
 		logrus.WithError(err).WithFields(logrus.Fields{
 			"ue-ip-addr": ps.UeInfo.Addr,

internal/app/setup.go

@@ -21,7 +21,7 @@ type Setup struct {
 }
 
 func NewSetup(config *config.CPConfig) *Setup {
-	smf := smf.NewSmf(config.Pfcp, config.Slices)
+	smf := smf.NewSmf(config.Pfcp, config.Slices, config.Areas)
 	return &Setup{
 		config: config,
 		amf:    amf.NewAmf(config.Control.BindAddr, config.Control.Uri, "go-github-nextmn-cp-lite", smf),

internal/config/config.go

@@ -33,9 +33,10 @@ func ParseConf(file string) (*CPConfig, error) {
 
 type CPConfig struct {
 	Control Control          `yaml:"control"`
-	Logger  *Logger          `yaml:"logger,omitempty"`
-	Slices  map[string]Slice `yaml:"slices"`
 	Pfcp    netip.Addr       `yaml:"pfcp"`
+	Slices  map[string]Slice `yaml:"slices"`
+	Areas   map[string]Area  `yaml:"areas"`
+	Logger  *Logger          `yaml:"logger,omitempty"`
 }
 
 type Control struct {
@@ -57,3 +58,8 @@ type Interface struct {
 	Type string     `yaml:"type"`
 	Addr netip.Addr `yaml:"addr"`
 }
+
+type Area struct {
+	Gnbs  []jsonapi.ControlURI    `yaml:"gnbs"`
+	Paths map[string][]netip.Addr `yaml:"paths"`
+}

internal/smf/area.go

@@ -0,0 +1,46 @@
+// Copyright Louis Royer and the NextMN contributors. All rights reserved.
+// Use of this source code is governed by a MIT-style license that can be
+// found in the LICENSE file.
+// SPDX-License-Identifier: MIT
+
+package smf
+
+import (
+	"slices"
+
+	"github.com/nextmn/cp-lite/internal/config"
+
+	"github.com/nextmn/json-api/jsonapi"
+)
+
+type AreasMap struct {
+	content map[string][]jsonapi.ControlURI
+}
+
+func NewAreasMap(areas map[string]config.Area) AreasMap {
+	m := AreasMap{
+		content: make(map[string][]jsonapi.ControlURI),
+	}
+	for k, area := range areas {
+		m.content[k] = area.Gnbs
+	}
+	return m
+}
+
+func (a AreasMap) Area(gnb jsonapi.ControlURI) (string, bool) {
+	for name, area := range a.content {
+		if slices.Contains(area, gnb) {
+			return name, true
+		}
+	}
+	return "", false
+}
+
+func (a AreasMap) Contains(areaName string, gnb jsonapi.ControlURI) bool {
+	if area, ok := a.content[areaName]; ok {
+		if slices.Contains(area, gnb) {
+			return true
+		}
+	}
+	return false
+}

internal/smf/errors.go

@@ -12,6 +12,8 @@ import (
 var (
 	ErrDnnNotFound        = errors.New("DNN not found")
 	ErrPDUSessionNotFound = errors.New("PDU Session not found")
+	ErrAreaNotFound       = errors.New("RAN Area not found for this gNB")
+	ErrPathNotFound       = errors.New("Path not found for this RAN Area")
 
 	ErrUpfNotAssociated    = errors.New("UPF not associated")
 	ErrUpfNotFound         = errors.New("UPF not found")

internal/smf/slice.go

@@ -16,14 +16,22 @@ type SlicesMap struct {
 	sync.Map // slice name: Slice
 }
 
-func NewSlicesMap(slices map[string]config.Slice) *SlicesMap {
+func NewSlicesMap(slices map[string]config.Slice, areas map[string]config.Area) *SlicesMap {
 	m := SlicesMap{}
 	for k, slice := range slices {
 		upfs := make([]netip.Addr, len(slice.Upfs))
 		for i, upf := range slice.Upfs {
 			upfs[i] = upf.NodeID
 		}
-		sl := NewSlice(slice.Pool, upfs)
+
+		paths := make(map[string][]netip.Addr)
+		for area_name, area := range areas {
+			if path, exists := area.Paths[k]; exists {
+				paths[area_name] = path
+			}
+		}
+
+		sl := NewSlice(slice.Pool, upfs, paths)
 		m.Store(k, sl)
 	}
 	return &m
@@ -33,12 +41,14 @@ type Slice struct {
 	Upfs     []netip.Addr
 	Pool     *UeIpPool
 	sessions *SessionsMap
+	Paths    map[string][]netip.Addr
 }
 
-func NewSlice(pool netip.Prefix, upfs []netip.Addr) *Slice {
+func NewSlice(pool netip.Prefix, upfs []netip.Addr, paths map[string][]netip.Addr) *Slice {
 	return &Slice{
 		Pool:     NewUeIpPool(pool),
 		Upfs:     upfs,
 		sessions: NewSessionsMap(),
+		Paths:    paths,
 	}
 }

internal/smf/smf.go

@@ -24,6 +24,7 @@ type UpfPath []netip.Addr
 type Smf struct {
 	upfs    *UpfsMap
 	slices  *SlicesMap
+	areas   AreasMap
 	srv     *pfcp.PFCPEntityCP
 	started bool
 	closed  chan struct{}
@@ -32,13 +33,14 @@ type Smf struct {
 	ctx context.Context
 }
 
-func NewSmf(addr netip.Addr, slices map[string]config.Slice) *Smf {
-	s := NewSlicesMap(slices)
+func NewSmf(addr netip.Addr, slices map[string]config.Slice, areas map[string]config.Area) *Smf {
+	s := NewSlicesMap(slices, areas)
 	upfs := NewUpfsMap(slices)
 	return &Smf{
 		srv:    pfcp.NewPFCPEntityCP(addr.String(), addr),
 		slices: s,
 		upfs:   upfs,
+		areas:  NewAreasMap(areas),
 		closed: make(chan struct{}),
 		ctx:    nil,
 	}
@@ -101,11 +103,11 @@ func (smf *Smf) Context() context.Context {
 	return context.Background()
 }
 
-func (smf *Smf) CreateSessionDownlink(ueCtrl jsonapi.ControlURI, ueIp netip.Addr, dnn string, gnb netip.Addr, gnb_teid uint32) (*PduSessionN3, error) {
-	return smf.CreateSessionDownlinkContext(smf.ctx, ueCtrl, ueIp, dnn, gnb, gnb_teid)
+func (smf *Smf) CreateSessionDownlink(ueCtrl jsonapi.ControlURI, ueIp netip.Addr, dnn string, gnbCtrl jsonapi.ControlURI, gnbFteid jsonapi.Fteid) (*PduSessionN3, error) {
+	return smf.CreateSessionDownlinkContext(smf.ctx, ueCtrl, ueIp, dnn, gnbCtrl, gnbFteid)
 }
 
-func (smf *Smf) CreateSessionDownlinkContext(ctx context.Context, ueCtrl jsonapi.ControlURI, ueIp netip.Addr, dnn string, gnb netip.Addr, gnb_teid uint32) (*PduSessionN3, error) {
+func (smf *Smf) CreateSessionDownlinkContext(ctx context.Context, ueCtrl jsonapi.ControlURI, ueIp netip.Addr, dnn string, gnbCtrl jsonapi.ControlURI, gnbFteid jsonapi.Fteid) (*PduSessionN3, error) {
 	if !smf.started {
 		return nil, ErrSmfNotStarted
 	}
@@ -131,12 +133,23 @@ func (smf *Smf) CreateSessionDownlinkContext(ctx context.Context, ueCtrl jsonapi
 	if err != nil {
 		return nil, err
 	}
-	session.DownlinkFteid = jsonapi.NewFteid(gnb, gnb_teid)
+	session.DownlinkFteid = &gnbFteid
 	if len(slice.Upfs) == 0 {
 		return nil, ErrUpfNotFound
 	}
 	last_fteid := session.DownlinkFteid
-	for i, upf_ctrl := range slice.Upfs {
+
+	area, ok := smf.areas.Area(gnbCtrl)
+	if !ok {
+		return nil, ErrAreaNotFound
+	}
+
+	path, ok := slice.Paths[area]
+	if !ok {
+		return nil, ErrPathNotFound
+	}
+
+	for i, upf_ctrl := range path {
 		upf_any, ok := smf.upfs.Load(upf_ctrl)
 		if !ok {
 			return nil, ErrUpfNotFound
@@ -202,18 +215,28 @@ func (smf *Smf) CreateSessionUplinkContext(ctx context.Context, ueCtrl jsonapi.C
 	}
 	// create new session
 	// 1. check path
-	if len(slice.Upfs) == 0 {
+	area, ok := smf.areas.Area(gnbCtrl)
+	if !ok {
+		return nil, ErrAreaNotFound
+	}
+
+	path, ok := slice.Paths[area]
+	if !ok {
+		return nil, ErrPathNotFound
+	}
+
+	if len(path) == 0 {
 		return nil, ErrUpfNotFound
 	}
 	// 2. init anchor
-	upfa_ctrl := slice.Upfs[len(slice.Upfs)-1]
+	upfa_ctrl := path[len(path)-1]
 	upfa_any, ok := smf.upfs.Load(upfa_ctrl)
 	if !ok {
 		return nil, ErrUpfNotFound
 	}
 	upfa := upfa_any.(*Upf)
 	var upfa_iface netip.Addr
-	if len(slice.Upfs) == 1 {
+	if len(path) == 1 {
 		upfa_iface, err = upfa.GetN3()
 		if err != nil {
 			logrus.WithError(err).WithFields(logrus.Fields{
@@ -243,8 +266,8 @@ func (smf *Smf) CreateSessionUplinkContext(ctx context.Context, ueCtrl jsonapi.C
 	}
 
 	// 3. init path from anchor
-	for i := len(slice.Upfs) - 2; i >= 0; i-- {
-		upf_ctrl := slice.Upfs[i]
+	for i := len(path) - 2; i >= 0; i-- {
+		upf_ctrl := path[i]
 		upf_any, ok := smf.upfs.Load(upf_ctrl)
 		if !ok {
 			return nil, ErrUpfNotFound
@@ -333,25 +356,37 @@ func (smf *Smf) StoreNextDownlinkFteid(ueCtrl jsonapi.ControlURI, ueAddr netip.A
 	return slice.(*Slice).sessions.SetNextDownlinkFteid(ueCtrl, ueAddr, fteid)
 }
 
-func (smf *Smf) UpdateSessionDownlink(ueCtrl jsonapi.ControlURI, ueAddr netip.Addr, dnn string) error {
-	return smf.UpdateSessionDownlinkContext(smf.ctx, ueCtrl, ueAddr, dnn)
+func (smf *Smf) UpdateSessionDownlink(ueCtrl jsonapi.ControlURI, ueAddr netip.Addr, dnn string, oldGnbCtrl jsonapi.ControlURI) error {
+	return smf.UpdateSessionDownlinkContext(smf.ctx, ueCtrl, ueAddr, dnn, oldGnbCtrl)
 }
 
 // Updates Session to NextDownlinkFteid
-func (smf *Smf) UpdateSessionDownlinkContext(ctx context.Context, ueCtrl jsonapi.ControlURI, ueAddr netip.Addr, dnn string) error {
-	slice, ok := smf.slices.Load(dnn)
+func (smf *Smf) UpdateSessionDownlinkContext(ctx context.Context, ueCtrl jsonapi.ControlURI, ueAddr netip.Addr, dnn string, oldGnbCtrl jsonapi.ControlURI) error {
+	s, ok := smf.slices.Load(dnn)
 	if !ok {
 		return ErrDnnNotFound
 	}
-	session, err := slice.(*Slice).sessions.Get(ueCtrl, ueAddr)
+	slice := s.(*Slice)
+
+	session, err := slice.sessions.Get(ueCtrl, ueAddr)
 	if err != nil {
 		return err
 	}
 
-	if len(slice.(*Slice).Upfs) == 0 {
+	area, ok := smf.areas.Area(oldGnbCtrl)
+	if !ok {
+		return ErrAreaNotFound
+	}
+
+	path, ok := slice.Paths[area]
+	if !ok {
+		return ErrPathNotFound
+	}
+
+	if len(path) == 0 {
 		return ErrUpfNotFound
 	}
-	upf_ctrl := slice.(*Slice).Upfs[0] // upf-i
+	upf_ctrl := path[0] // upf-i
 	upf_any, ok := smf.upfs.Load(upf_ctrl)
 	if !ok {
 		return ErrUpfNotFound