Fix IPSec allocate error

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/free5gc/ike v1.1.1-0.20241014015325-083f89768f43
 	github.com/free5gc/ngap v1.0.9-0.20240708062829-734d184eed74
 	github.com/free5gc/sctp v1.0.1
-	github.com/free5gc/util v1.0.7-0.20240713162917-350ee8f4af4c
+	github.com/free5gc/util v1.0.7-0.20241016064137-5698cc626593
 	github.com/gin-contrib/pprof v1.5.0
 	github.com/gin-gonic/gin v1.10.0
 	github.com/google/gopacket v1.1.19

go.sum

@@ -24,8 +24,8 @@ github.com/free5gc/openapi v1.0.9-0.20240503143645-eac9f06c2f6b h1:+VcgZq+3apB6X
 github.com/free5gc/openapi v1.0.9-0.20240503143645-eac9f06c2f6b/go.mod h1:0qRW+H1/Nyzw5tjjvyp+90m+2SOZZefGQC9QV8iPwu8=
 github.com/free5gc/sctp v1.0.1 h1:g8WDO97r8B9ubkT5Hyk9b4I1fZUOii9Z39gQ2eRaASo=
 github.com/free5gc/sctp v1.0.1/go.mod h1:7QXfRWCmlkBGD0EIu3qL5o71bslfIakydz4h2QDZdjQ=
-github.com/free5gc/util v1.0.7-0.20240713162917-350ee8f4af4c h1:baToZn4hxGKoCm3BWwYlRuZoCQ74cMZUJzg9BVLEdE0=
-github.com/free5gc/util v1.0.7-0.20240713162917-350ee8f4af4c/go.mod h1:IHKIBd4OM9rwSJ0fG/hv6pXbVC+Eu4Lcaq++BWkfSsY=
+github.com/free5gc/util v1.0.7-0.20241016064137-5698cc626593 h1:Wp32mLckyP25feOmwHBTS32pSkIAjuZgq8iP7njbe/k=
+github.com/free5gc/util v1.0.7-0.20241016064137-5698cc626593/go.mod h1:IHKIBd4OM9rwSJ0fG/hv6pXbVC+Eu4Lcaq++BWkfSsY=
 github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
 github.com/gabriel-vasile/mimetype v1.4.3/go.mod h1:d8uq/6HKRL6CGdk+aubisF/M5GcPfT7nKyLpA0lbSSk=
 github.com/gin-contrib/pprof v1.5.0 h1:E/Oy7g+kNw94KfdCy3bZxQFtyDnAX2V7axRS7sNYVrU=

internal/context/context.go

@@ -26,6 +26,7 @@ import (
 	"github.com/free5gc/openapi/models"
 	"github.com/free5gc/sctp"
 	"github.com/free5gc/util/idgenerator"
+	"github.com/free5gc/util/ippool"
 )
 
 type n3iwf interface {
@@ -59,7 +60,8 @@ type N3IWFContext struct {
 	N3IWFCertificate     []byte
 	N3IWFPrivateKey      *rsa.PrivateKey
 
-	UeIPRange *net.IPNet
+	IPSecInnerIPPool *ippool.IPPool
+	// TODO: [TWIF] TwifUe may has its own IP address pool
 
 	/* XFRM interface */
 	XfrmIfaces          sync.Map // map[uint32]*netlink.Link, XfrmIfaceId as key
@@ -130,11 +132,11 @@ func NewContext(n3iwf n3iwf) (*N3IWFContext, error) {
 	n.N3IWFCertificate = block.Bytes
 
 	// UE IP address range
-	_, ueIPRange, err := net.ParseCIDR(cfg.GetUEIPAddrRange())
+	ueIPPool, err := ippool.NewIPPool(cfg.GetUEIPAddrRange())
 	if err != nil {
-		return nil, errors.Errorf("Parse CIDR failed: %+v", err)
+		return nil, errors.Errorf("NewContext(): %+v", err)
 	}
-	n.UeIPRange = ueIPRange
+	n.IPSecInnerIPPool = ueIPPool
 
 	// XFRM related
 	ikeBindIfaceName, err := getInterfaceName(cfg.GetIKEBindAddr())
@@ -461,26 +463,30 @@ func (c *N3IWFContext) GTPConnectionWithUPFStore(upfAddr string, conn *gtpv1.UPl
 	c.GTPConnectionWithUPF.Store(upfAddr, conn)
 }
 
-func (c *N3IWFContext) NewInternalUEIPAddr(ikeUe *N3IWFIkeUe) net.IP {
+func (c *N3IWFContext) NewIPsecInnerUEIP(ikeUe *N3IWFIkeUe) (net.IP, error) {
 	var ueIPAddr net.IP
-
+	var err error
 	cfg := c.Config()
 	ipsecGwAddr := cfg.GetIPSecGatewayAddr()
-	// TODO: Check number of allocated IP to detect running out of IPs
+
 	for {
-		ueIPAddr = generateRandomIPinRange(c.UeIPRange)
-		if ueIPAddr != nil {
-			if ueIPAddr.String() == ipsecGwAddr {
-				continue
-			}
-			_, ok := c.AllocatedUEIPAddress.LoadOrStore(ueIPAddr.String(), ikeUe)
-			if !ok {
-				break
-			}
+		ueIPAddr, err = c.IPSecInnerIPPool.Allocate(nil)
+		if err != nil {
+			return nil, errors.Wrapf(err, "NewIPsecInnerUEIP()")
+		}
+		if ueIPAddr.String() == ipsecGwAddr {
+			continue
+		}
+		_, ok := c.AllocatedUEIPAddress.LoadOrStore(ueIPAddr.String(), ikeUe)
+		if ok {
+			logger.CtxLog.Warnf("NewIPsecInnerUEIP(): IP(%v) is used by other IkeUE",
+				ueIPAddr.String())
+		} else {
+			break
 		}
 	}
 
-	return ueIPAddr
+	return ueIPAddr, nil
 }
 
 func (c *N3IWFContext) DeleteInternalUEIPAddr(ipAddr string) {
@@ -554,22 +560,3 @@ func (c *N3IWFContext) AMFSelection(
 	}
 	return availableAMF
 }
-
-func generateRandomIPinRange(subnet *net.IPNet) net.IP {
-	ipAddr := make([]byte, 4)
-	randomNumber := make([]byte, 4)
-
-	_, err := rand.Read(randomNumber)
-	if err != nil {
-		logger.CtxLog.Errorf("Generate random number for IP address failed: %+v", err)
-		return nil
-	}
-
-	// TODO: elimenate network name, gateway, and broadcast
-	for i := 0; i < 4; i++ {
-		alter := randomNumber[i] & (subnet.Mask[i] ^ 255)
-		ipAddr[i] = subnet.IP[i] + alter
-	}
-
-	return net.IPv4(ipAddr[0], ipAddr[1], ipAddr[2], ipAddr[3])
-}

internal/context/context_test.go

@@ -0,0 +1,106 @@
+package context_test
+
+import (
+	"context"
+	"net"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	n3iwf_context "github.com/free5gc/n3iwf/internal/context"
+	"github.com/free5gc/n3iwf/pkg/factory"
+	"github.com/free5gc/util/ippool"
+)
+
+type n3iwfTestApp struct {
+	cfg      *factory.Config
+	n3iwfCtx *n3iwf_context.N3IWFContext
+	ctx      context.Context
+	cancel   context.CancelFunc
+	wg       *sync.WaitGroup
+}
+
+func (a *n3iwfTestApp) Config() *factory.Config {
+	return a.cfg
+}
+
+func (a *n3iwfTestApp) Context() *n3iwf_context.N3IWFContext {
+	return a.n3iwfCtx
+}
+
+func (a *n3iwfTestApp) CancelContext() context.Context {
+	return a.ctx
+}
+
+func NewN3iwfTestApp(cfg *factory.Config) (*n3iwfTestApp, error) {
+	var err error
+	ctx, cancel := context.WithCancel(context.Background())
+
+	n3iwfApp := &n3iwfTestApp{
+		cfg:    cfg,
+		ctx:    ctx,
+		cancel: cancel,
+		wg:     &sync.WaitGroup{},
+	}
+
+	n3iwfApp.n3iwfCtx, err = n3iwf_context.NewTestContext(n3iwfApp)
+	if err != nil {
+		return nil, err
+	}
+	return n3iwfApp, err
+}
+
+func NewTestCfg() *factory.Config {
+	return &factory.Config{
+		Configuration: &factory.Configuration{
+			IPSecGatewayAddr: "10.0.0.1",
+			UEIPAddressRange: "10.0.0.0/24",
+		},
+	}
+}
+
+func TestNewInternalUEIPAddr(t *testing.T) {
+	cfg := NewTestCfg()
+	var app *n3iwfTestApp
+	var err error
+	var ip, invalidIP, invalidIP2 net.IP
+
+	app, err = NewN3iwfTestApp(cfg)
+	require.NoError(t, err)
+
+	n3iwfCtx := app.n3iwfCtx
+
+	invalidIP = net.ParseIP("10.0.0.0")
+	invalidIP2 = net.ParseIP("10.0.0.255")
+	n3iwfCtx.IPSecInnerIPPool, err = ippool.NewIPPool("10.0.0.0/24")
+	require.NoError(t, err)
+
+	for i := 1; i <= 253; i++ {
+		ip, err = n3iwfCtx.NewIPsecInnerUEIP(&n3iwf_context.N3IWFIkeUe{})
+		require.NoError(t, err)
+		require.NotEqual(t, cfg.GetIPSecGatewayAddr(), ip.String())
+		require.NotEqual(t, ip, invalidIP)
+		require.NotEqual(t, ip, invalidIP2)
+	}
+
+	_, err = n3iwfCtx.NewIPsecInnerUEIP(&n3iwf_context.N3IWFIkeUe{})
+	require.Error(t, err)
+
+	n3iwfCtx.AllocatedUEIPAddress = sync.Map{}
+
+	n3iwfCtx.IPSecInnerIPPool, err = ippool.NewIPPool("10.0.0.0/16")
+	require.NoError(t, err)
+
+	invalidIP2 = net.ParseIP("10.0.255.255")
+	for i := 1; i <= 65533; i++ {
+		ip, err = n3iwfCtx.NewIPsecInnerUEIP(&n3iwf_context.N3IWFIkeUe{})
+		require.NoError(t, err)
+		require.NotEqual(t, cfg.GetIPSecGatewayAddr(), ip.String())
+		require.NotEqual(t, ip, invalidIP)
+		require.NotEqual(t, ip, invalidIP2)
+	}
+
+	_, err = n3iwfCtx.NewIPsecInnerUEIP(&n3iwf_context.N3IWFIkeUe{})
+	require.Error(t, err)
+}

internal/context/ikeue.go

@@ -217,6 +217,11 @@ func (ikeUe *N3IWFIkeUe) Remove() error {
 	n3iwfCtx.DeleteIKESecurityAssociation(ikeUe.N3IWFIKESecurityAssociation.LocalSPI)
 	n3iwfCtx.DeleteInternalUEIPAddr(ikeUe.IPSecInnerIP.String())
 
+	err := n3iwfCtx.IPSecInnerIPPool.Release(net.ParseIP(ikeUe.IPSecInnerIP.String()).To4())
+	if err != nil {
+		return errors.Wrapf(err, "N3IWFIkeUe Remove()")
+	}
+
 	for _, childSA := range ikeUe.N3IWFChildSecurityAssociation {
 		if err := ikeUe.DeleteChildSA(childSA); err != nil {
 			return err

internal/ike/handler.go

@@ -737,15 +737,21 @@ func (s *Server) HandleIKEAUTH(
 		var ueIPAddr, n3iwfIPAddr net.IP
 		if addrRequest {
 			// IP addresses (IPSec)
-			ueIPAddr = n3iwfCtx.NewInternalUEIPAddr(ikeUE).To4()
+			var ueIp net.IP
+			ueIp, err = n3iwfCtx.NewIPsecInnerUEIP(ikeUE)
+			if err != nil {
+				ikeLog.Errorf("HandleIKEAUTH(): %v", err)
+				return
+			}
+			ueIPAddr = ueIp.To4()
 			n3iwfIPAddr = net.ParseIP(ipsecGwAddr).To4()
 
 			responseConfiguration := responseIKEPayload.BuildConfiguration(
 				ike_message.CFG_REPLY)
 			responseConfiguration.ConfigurationAttribute.BuildConfigurationAttribute(
 				ike_message.INTERNAL_IP4_ADDRESS, ueIPAddr)
 			responseConfiguration.ConfigurationAttribute.BuildConfigurationAttribute(
-				ike_message.INTERNAL_IP4_NETMASK, n3iwfCtx.UeIPRange.Mask)
+				ike_message.INTERNAL_IP4_NETMASK, n3iwfCtx.IPSecInnerIPPool.IPSubnet.Mask)
 
 			var ipsecInnerIPAddr *net.IPAddr
 			ikeUE.IPSecInnerIP = ueIPAddr
@@ -1072,7 +1078,7 @@ func (s *Server) continueCreateChildSA(
 		// Setup XFRM interface for ipsec
 		var linkIPSec netlink.Link
 		n3iwfIPAddr := net.ParseIP(ipsecGwAddr).To4()
-		n3iwfIPAddrAndSubnet := net.IPNet{IP: n3iwfIPAddr, Mask: n3iwfCtx.UeIPRange.Mask}
+		n3iwfIPAddrAndSubnet := net.IPNet{IP: n3iwfIPAddr, Mask: n3iwfCtx.IPSecInnerIPPool.IPSubnet.Mask}
 		newXfrmiId += cfg.GetXfrmIfaceId() + n3iwfCtx.XfrmIfaceIdOffsetForUP
 		newXfrmiName := fmt.Sprintf("%s-%d", cfg.GetXfrmIfaceName(), newXfrmiId)
 
@@ -1152,7 +1158,6 @@ func (s *Server) HandleInformational(
 		switch ikePayload.Type() {
 		case ike_message.TypeD:
 			deletePayload = ikePayload.(*ike_message.Delete)
-
 		default:
 			ikeLog.Warnf(
 				"Get IKE payload (type %d) in Inoformational message, this payload will not be handled by IKE handler",

internal/ike/handler_test.go

@@ -9,6 +9,7 @@ import (
 	ike_message "github.com/free5gc/ike/message"
 	n3iwf_context "github.com/free5gc/n3iwf/internal/context"
 	"github.com/free5gc/n3iwf/pkg/factory"
+	"github.com/free5gc/util/ippool"
 )
 
 func TestRemoveIkeUe(t *testing.T) {
@@ -22,8 +23,14 @@ func TestRemoveIkeUe(t *testing.T) {
 	ikeSA := n3iwfCtx.NewIKESecurityAssociation()
 	ikeUe := n3iwfCtx.NewN3iwfIkeUe(ikeSA.LocalSPI)
 	ikeUe.N3IWFIKESecurityAssociation = ikeSA
+	ikeUe.IPSecInnerIP = net.ParseIP("10.0.0.1")
 	ikeSA.IsUseDPD = false
 
+	n3iwfCtx.IPSecInnerIPPool, err = ippool.NewIPPool("10.0.0.0/24")
+	require.NoError(t, err)
+	_, err = n3iwfCtx.IPSecInnerIPPool.Allocate(nil)
+	require.NoError(t, err)
+
 	ikeUe.CreateHalfChildSA(1, 123, 1)
 
 	ikeAuth := &ike_message.SecurityAssociation{}

internal/ike/server.go

@@ -3,6 +3,7 @@ package ike
 import (
 	"bytes"
 	"context"
+	"encoding/hex"
 	"fmt"
 	"net"
 	"runtime/debug"
@@ -173,6 +174,7 @@ func (s *Server) receiver(
 
 		msgBuf := make([]byte, n)
 		copy(msgBuf, buf)
+		ikeLog.Tracef("recv from port(%d):\n%s", localAddr.Port, hex.Dump(msgBuf))
 
 		// As specified in RFC 7296 section 3.1, the IKE message send from/to UDP port 4500
 		// should prepend a 4 bytes zero
@@ -349,14 +351,17 @@ func constructPacketWithESP(srcIP, dstIP *net.UDPAddr, espPacket []byte) ([]byte
 }
 
 func handleESPPacket(srcIP, dstIP *net.UDPAddr, espPacket []byte) error {
+	ikeLog := logger.IKELog
+	ikeLog.Tracef("Handle ESPPacket")
+
 	fd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, syscall.IPPROTO_RAW)
 	if err != nil {
 		return errors.Errorf("socket error: %v", err)
 	}
 
 	defer func() {
 		if err = syscall.Close(fd); err != nil {
-			logger.IKELog.Errorf("Close fd error : %v", err)
+			ikeLog.Errorf("Close fd error : %v", err)
 		}
 	}()
 

pkg/service/init.go

@@ -205,7 +205,7 @@ func (a *N3iwfApp) initDefaultXfrmInterface() error {
 	cfg := a.Config()
 	mainLog := logger.MainLog
 	n3iwfIPAddr := net.ParseIP(cfg.GetIPSecGatewayAddr()).To4()
-	n3iwfIPAddrAndSubnet := net.IPNet{IP: n3iwfIPAddr, Mask: n3iwfCtx.UeIPRange.Mask}
+	n3iwfIPAddrAndSubnet := net.IPNet{IP: n3iwfIPAddr, Mask: n3iwfCtx.IPSecInnerIPPool.IPSubnet.Mask}
 	newXfrmiName := fmt.Sprintf("%s-default", cfg.GetXfrmIfaceName())
 
 	if linkIPSec, err = xfrm.SetupIPsecXfrmi(newXfrmiName, n3iwfCtx.XfrmParentIfaceName,
@@ -216,7 +216,7 @@ func (a *N3iwfApp) initDefaultXfrmInterface() error {
 
 	route := &netlink.Route{
 		LinkIndex: linkIPSec.Attrs().Index,
-		Dst:       n3iwfCtx.UeIPRange,
+		Dst:       n3iwfCtx.IPSecInnerIPPool.IPSubnet,
 	}
 
 	if err := netlink.RouteAdd(route); err != nil {