try to fix windows?

it is about 4.4% better on the bench-cpu-long cpu usage test

batch_pipeline.go

@@ -1,164 +0,0 @@
-package nebula
-
-import (
-	"net/netip"
-
-	"github.com/slackhq/nebula/overlay"
-	"github.com/slackhq/nebula/udp"
-)
-
-// batchPipelines tracks whether the inside device can operate on packet batches
-// and, if so, holds the shared packet pool sized for the virtio headroom and
-// payload limits advertised by the device. It also owns the fan-in/fan-out
-// queues between the TUN readers, encrypt/decrypt workers, and the UDP writers.
-type batchPipelines struct {
-	enabled    bool
-	inside     overlay.BatchCapableDevice
-	headroom   int
-	payloadCap int
-	pool       *overlay.PacketPool
-	batchSize  int
-	routines   int
-	rxQueues   []chan *overlay.Packet
-	txQueues   []chan queuedDatagram
-	tunQueues  []chan *overlay.Packet
-}
-
-type queuedDatagram struct {
-	packet *overlay.Packet
-	addr   netip.AddrPort
-}
-
-func (bp *batchPipelines) init(device overlay.Device, routines int, queueDepth int, maxSegments int) {
-	if device == nil || routines <= 0 {
-		return
-	}
-	bcap, ok := device.(overlay.BatchCapableDevice)
-	if !ok {
-		return
-	}
-	headroom := bcap.BatchHeadroom()
-	payload := bcap.BatchPayloadCap()
-	if maxSegments < 1 {
-		maxSegments = 1
-	}
-	requiredPayload := udp.MTU * maxSegments
-	if payload < requiredPayload {
-		payload = requiredPayload
-	}
-	batchSize := bcap.BatchSize()
-	if headroom <= 0 || payload <= 0 || batchSize <= 0 {
-		return
-	}
-	bp.enabled = true
-	bp.inside = bcap
-	bp.headroom = headroom
-	bp.payloadCap = payload
-	bp.batchSize = batchSize
-	bp.routines = routines
-	bp.pool = overlay.NewPacketPool(headroom, payload)
-	queueCap := batchSize * defaultBatchQueueDepthFactor
-	if queueDepth > 0 {
-		queueCap = queueDepth
-	}
-	if queueCap < batchSize {
-		queueCap = batchSize
-	}
-	bp.rxQueues = make([]chan *overlay.Packet, routines)
-	bp.txQueues = make([]chan queuedDatagram, routines)
-	bp.tunQueues = make([]chan *overlay.Packet, routines)
-	for i := 0; i < routines; i++ {
-		bp.rxQueues[i] = make(chan *overlay.Packet, queueCap)
-		bp.txQueues[i] = make(chan queuedDatagram, queueCap)
-		bp.tunQueues[i] = make(chan *overlay.Packet, queueCap)
-	}
-}
-
-func (bp *batchPipelines) Pool() *overlay.PacketPool {
-	if bp == nil || !bp.enabled {
-		return nil
-	}
-	return bp.pool
-}
-
-func (bp *batchPipelines) Enabled() bool {
-	return bp != nil && bp.enabled
-}
-
-func (bp *batchPipelines) batchSizeHint() int {
-	if bp == nil || bp.batchSize <= 0 {
-		return 1
-	}
-	return bp.batchSize
-}
-
-func (bp *batchPipelines) rxQueue(i int) chan *overlay.Packet {
-	if bp == nil || !bp.enabled || i < 0 || i >= len(bp.rxQueues) {
-		return nil
-	}
-	return bp.rxQueues[i]
-}
-
-func (bp *batchPipelines) txQueue(i int) chan queuedDatagram {
-	if bp == nil || !bp.enabled || i < 0 || i >= len(bp.txQueues) {
-		return nil
-	}
-	return bp.txQueues[i]
-}
-
-func (bp *batchPipelines) tunQueue(i int) chan *overlay.Packet {
-	if bp == nil || !bp.enabled || i < 0 || i >= len(bp.tunQueues) {
-		return nil
-	}
-	return bp.tunQueues[i]
-}
-
-func (bp *batchPipelines) txQueueLen(i int) int {
-	q := bp.txQueue(i)
-	if q == nil {
-		return 0
-	}
-	return len(q)
-}
-
-func (bp *batchPipelines) tunQueueLen(i int) int {
-	q := bp.tunQueue(i)
-	if q == nil {
-		return 0
-	}
-	return len(q)
-}
-
-func (bp *batchPipelines) enqueueRx(i int, pkt *overlay.Packet) bool {
-	q := bp.rxQueue(i)
-	if q == nil {
-		return false
-	}
-	q <- pkt
-	return true
-}
-
-func (bp *batchPipelines) enqueueTx(i int, pkt *overlay.Packet, addr netip.AddrPort) bool {
-	q := bp.txQueue(i)
-	if q == nil {
-		return false
-	}
-	q <- queuedDatagram{packet: pkt, addr: addr}
-	return true
-}
-
-func (bp *batchPipelines) enqueueTun(i int, pkt *overlay.Packet) bool {
-	q := bp.tunQueue(i)
-	if q == nil {
-		return false
-	}
-	q <- pkt
-	return true
-}
-
-func (bp *batchPipelines) newPacket() *overlay.Packet {
-	if bp == nil || !bp.enabled || bp.pool == nil {
-		return nil
-	}
-	return bp.pool.Get()
-}

cert/pem.go

@@ -1,10 +1,8 @@
 package cert
 
 import (
-	"encoding/hex"
 	"encoding/pem"
 	"fmt"
-	"time"
 
 	"golang.org/x/crypto/ed25519"
 )
@@ -140,101 +138,6 @@ func MarshalSigningPrivateKeyToPEM(curve Curve, b []byte) []byte {
 	}
 }
 
-// Backward compatibility functions for older API
-func MarshalX25519PublicKey(b []byte) []byte {
-	return MarshalPublicKeyToPEM(Curve_CURVE25519, b)
-}
-
-func MarshalX25519PrivateKey(b []byte) []byte {
-	return MarshalPrivateKeyToPEM(Curve_CURVE25519, b)
-}
-
-func MarshalPublicKey(curve Curve, b []byte) []byte {
-	return MarshalPublicKeyToPEM(curve, b)
-}
-
-func MarshalPrivateKey(curve Curve, b []byte) []byte {
-	return MarshalPrivateKeyToPEM(curve, b)
-}
-
-// NebulaCertificate is a compatibility wrapper for the old API
-type NebulaCertificate struct {
-	Details   NebulaCertificateDetails
-	Signature []byte
-	cert      Certificate
-}
-
-// NebulaCertificateDetails is a compatibility wrapper for certificate details
-type NebulaCertificateDetails struct {
-	Name      string
-	NotBefore time.Time
-	NotAfter  time.Time
-	PublicKey []byte
-	IsCA      bool
-	Issuer    []byte
-	Curve     Curve
-}
-
-// UnmarshalNebulaCertificateFromPEM provides backward compatibility with the old API
-func UnmarshalNebulaCertificateFromPEM(b []byte) (*NebulaCertificate, []byte, error) {
-	c, rest, err := UnmarshalCertificateFromPEM(b)
-	if err != nil {
-		return nil, rest, err
-	}
-
-	issuerBytes, err := func() ([]byte, error) {
-		issuer := c.Issuer()
-		if issuer == "" {
-			return nil, nil
-		}
-		decoded, err := hex.DecodeString(issuer)
-		if err != nil {
-			return nil, fmt.Errorf("failed to decode issuer fingerprint: %w", err)
-		}
-		return decoded, nil
-	}()
-	if err != nil {
-		return nil, rest, err
-	}
-
-	pubKey := c.PublicKey()
-	if pubKey != nil {
-		pubKey = append([]byte(nil), pubKey...)
-	}
-
-	sig := c.Signature()
-	if sig != nil {
-		sig = append([]byte(nil), sig...)
-	}
-
-	return &NebulaCertificate{
-		Details: NebulaCertificateDetails{
-			Name:      c.Name(),
-			NotBefore: c.NotBefore(),
-			NotAfter:  c.NotAfter(),
-			PublicKey: pubKey,
-			IsCA:      c.IsCA(),
-			Issuer:    issuerBytes,
-			Curve:     c.Curve(),
-		},
-		Signature: sig,
-		cert:      c,
-	}, rest, nil
-}
-
-// IssuerString returns the issuer in hex format for compatibility
-func (n *NebulaCertificate) IssuerString() string {
-	if n.Details.Issuer == nil {
-		return ""
-	}
-	return hex.EncodeToString(n.Details.Issuer)
-}
-
-// Certificate returns the underlying certificate (read-only)
-func (n *NebulaCertificate) Certificate() Certificate {
-	return n.cert
-}
-
 // UnmarshalPrivateKeyFromPEM will try to unmarshal the first pem block in a byte array, returning any non
 // consumed data or an error on failure
 func UnmarshalPrivateKeyFromPEM(b []byte) ([]byte, []byte, Curve, error) {

cert_test/cert.go

@@ -114,33 +114,6 @@ func NewTestCert(v cert.Version, curve cert.Curve, ca cert.Certificate, key []by
 	return c, pub, cert.MarshalPrivateKeyToPEM(curve, priv), pem
 }
 
-func NewTestCertDifferentVersion(c cert.Certificate, v cert.Version, ca cert.Certificate, key []byte) (cert.Certificate, []byte) {
-	nc := &cert.TBSCertificate{
-		Version:        v,
-		Curve:          c.Curve(),
-		Name:           c.Name(),
-		Networks:       c.Networks(),
-		UnsafeNetworks: c.UnsafeNetworks(),
-		Groups:         c.Groups(),
-		NotBefore:      time.Unix(c.NotBefore().Unix(), 0),
-		NotAfter:       time.Unix(c.NotAfter().Unix(), 0),
-		PublicKey:      c.PublicKey(),
-		IsCA:           false,
-	}
-
-	c, err := nc.Sign(ca, ca.Curve(), key)
-	if err != nil {
-		panic(err)
-	}
-
-	pem, err := c.MarshalPEM()
-	if err != nil {
-		panic(err)
-	}
-
-	return c, pem
-}
-
 func X25519Keypair() ([]byte, []byte) {
 	privkey := make([]byte, 32)
 	if _, err := io.ReadFull(rand.Reader, privkey); err != nil {

connection_manager.go

@@ -354,6 +354,7 @@ func (cm *connectionManager) makeTrafficDecision(localIndex uint32, now time.Tim
 
 		if mainHostInfo {
 			decision = tryRehandshake
+
 		} else {
 			if cm.shouldSwapPrimary(hostinfo) {
 				decision = swapPrimary
@@ -460,10 +461,6 @@ func (cm *connectionManager) shouldSwapPrimary(current *HostInfo) bool {
 	}
 
 	crt := cm.intf.pki.getCertState().getCertificate(current.ConnectionState.myCert.Version())
-	if crt == nil {
-		//my cert was reloaded away. We should definitely swap from this tunnel
-		return true
-	}
 	// If this tunnel is using the latest certificate then we should swap it to primary for a bit and see if things
 	// settle down.
 	return bytes.Equal(current.ConnectionState.myCert.Signature(), crt.Signature())
@@ -478,34 +475,31 @@ func (cm *connectionManager) swapPrimary(current, primary *HostInfo) {
 	cm.hostMap.Unlock()
 }
 
-// isInvalidCertificate decides if we should destroy a tunnel.
+// isInvalidCertificate will check if we should destroy a tunnel if pki.disconnect_invalid is true and
-// returns true if pki.disconnect_invalid is true and the certificate is no longer valid.
+// the certificate is no longer valid. Block listed certificates will skip the pki.disconnect_invalid
-// Blocklisted certificates will skip the pki.disconnect_invalid check and return true.
+// check and return true.
 func (cm *connectionManager) isInvalidCertificate(now time.Time, hostinfo *HostInfo) bool {
 	remoteCert := hostinfo.GetCert()
 	if remoteCert == nil {
-		return false //don't tear down tunnels for handshakes in progress
+		return false
 	}
 
 	caPool := cm.intf.pki.GetCAPool()
 	err := caPool.VerifyCachedCertificate(now, remoteCert)
 	if err == nil {
-		return false //cert is still valid! yay!
+		return false
-	} else if err == cert.ErrBlockListed { //avoiding errors.Is for speed
+	}
+
+	if !cm.intf.disconnectInvalid.Load() && err != cert.ErrBlockListed {
 		// Block listed certificates should always be disconnected
-		hostinfo.logger(cm.l).WithError(err).
+		return false
-			WithField("fingerprint", remoteCert.Fingerprint).
+	}
-			Info("Remote certificate is blocked, tearing down the tunnel")
+
-		return true
-	} else if cm.intf.disconnectInvalid.Load() {
 	hostinfo.logger(cm.l).WithError(err).
 		WithField("fingerprint", remoteCert.Fingerprint).
 		Info("Remote certificate is no longer valid, tearing down the tunnel")
+
 	return true
-	} else {
-		//if we reach here, the cert is no longer valid, but we're configured to keep tunnels from now-invalid certs open
-		return false
-	}
 }
 
 func (cm *connectionManager) sendPunch(hostinfo *HostInfo) {
@@ -536,45 +530,15 @@ func (cm *connectionManager) sendPunch(hostinfo *HostInfo) {
 func (cm *connectionManager) tryRehandshake(hostinfo *HostInfo) {
 	cs := cm.intf.pki.getCertState()
 	curCrt := hostinfo.ConnectionState.myCert
-	curCrtVersion := curCrt.Version()
+	myCrt := cs.getCertificate(curCrt.Version())
-	myCrt := cs.getCertificate(curCrtVersion)
+	if curCrt.Version() >= cs.initiatingVersion && bytes.Equal(curCrt.Signature(), myCrt.Signature()) == true {
-	if myCrt == nil {
+		// The current tunnel is using the latest certificate and version, no need to rehandshake.
-		cm.l.WithField("vpnAddrs", hostinfo.vpnAddrs).
-			WithField("version", curCrtVersion).
-			WithField("reason", "local certificate removed").
-			Info("Re-handshaking with remote")
-		cm.intf.handshakeManager.StartHandshake(hostinfo.vpnAddrs[0], nil)
 		return
 	}
-	peerCrt := hostinfo.ConnectionState.peerCert
+
-	if peerCrt != nil && curCrtVersion < peerCrt.Certificate.Version() {
-		// if our certificate version is less than theirs, and we have a matching version available, rehandshake?
-		if cs.getCertificate(peerCrt.Certificate.Version()) != nil {
-			cm.l.WithField("vpnAddrs", hostinfo.vpnAddrs).
-				WithField("version", curCrtVersion).
-				WithField("peerVersion", peerCrt.Certificate.Version()).
-				WithField("reason", "local certificate version lower than peer, attempting to correct").
-				Info("Re-handshaking with remote")
-			cm.intf.handshakeManager.StartHandshake(hostinfo.vpnAddrs[0], func(hh *HandshakeHostInfo) {
-				hh.initiatingVersionOverride = peerCrt.Certificate.Version()
-			})
-			return
-		}
-	}
-	if !bytes.Equal(curCrt.Signature(), myCrt.Signature()) {
 	cm.l.WithField("vpnAddrs", hostinfo.vpnAddrs).
 		WithField("reason", "local certificate is not current").
 		Info("Re-handshaking with remote")
 
 	cm.intf.handshakeManager.StartHandshake(hostinfo.vpnAddrs[0], nil)
-		return
-	}
-	if curCrtVersion < cs.initiatingVersion {
-		cm.l.WithField("vpnAddrs", hostinfo.vpnAddrs).
-			WithField("reason", "current cert version < pki.initiatingVersion").
-			Info("Re-handshaking with remote")
-
-		cm.intf.handshakeManager.StartHandshake(hostinfo.vpnAddrs[0], nil)
-		return
-	}
 }

e2e/helpers_test.go

@@ -129,109 +129,6 @@ func newSimpleServer(v cert.Version, caCrt cert.Certificate, caKey []byte, name
 	return control, vpnNetworks, udpAddr, c
 }
 
-// newServer creates a nebula instance with fewer assumptions
-func newServer(caCrt []cert.Certificate, certs []cert.Certificate, key []byte, overrides m) (*nebula.Control, []netip.Prefix, netip.AddrPort, *config.C) {
-	l := NewTestLogger()
-
-	vpnNetworks := certs[len(certs)-1].Networks()
-
-	var udpAddr netip.AddrPort
-	if vpnNetworks[0].Addr().Is4() {
-		budpIp := vpnNetworks[0].Addr().As4()
-		budpIp[1] -= 128
-		udpAddr = netip.AddrPortFrom(netip.AddrFrom4(budpIp), 4242)
-	} else {
-		budpIp := vpnNetworks[0].Addr().As16()
-		// beef for funsies
-		budpIp[2] = 190
-		budpIp[3] = 239
-		udpAddr = netip.AddrPortFrom(netip.AddrFrom16(budpIp), 4242)
-	}
-
-	caStr := ""
-	for _, ca := range caCrt {
-		x, err := ca.MarshalPEM()
-		if err != nil {
-			panic(err)
-		}
-		caStr += string(x)
-	}
-	certStr := ""
-	for _, c := range certs {
-		x, err := c.MarshalPEM()
-		if err != nil {
-			panic(err)
-		}
-		certStr += string(x)
-	}
-
-	mc := m{
-		"pki": m{
-			"ca":   caStr,
-			"cert": certStr,
-			"key":  string(key),
-		},
-		//"tun": m{"disabled": true},
-		"firewall": m{
-			"outbound": []m{{
-				"proto": "any",
-				"port":  "any",
-				"host":  "any",
-			}},
-			"inbound": []m{{
-				"proto": "any",
-				"port":  "any",
-				"host":  "any",
-			}},
-		},
-		//"handshakes": m{
-		//	"try_interval": "1s",
-		//},
-		"listen": m{
-			"host": udpAddr.Addr().String(),
-			"port": udpAddr.Port(),
-		},
-		"logging": m{
-			"timestamp_format": fmt.Sprintf("%v 15:04:05.000000", certs[0].Name()),
-			"level":            l.Level.String(),
-		},
-		"timers": m{
-			"pending_deletion_interval": 2,
-			"connection_alive_interval": 2,
-		},
-	}
-
-	if overrides != nil {
-		final := m{}
-		err := mergo.Merge(&final, overrides, mergo.WithAppendSlice)
-		if err != nil {
-			panic(err)
-		}
-		err = mergo.Merge(&final, mc, mergo.WithAppendSlice)
-		if err != nil {
-			panic(err)
-		}
-		mc = final
-	}
-
-	cb, err := yaml.Marshal(mc)
-	if err != nil {
-		panic(err)
-	}
-
-	c := config.NewC(l)
-	cStr := string(cb)
-	c.LoadString(cStr)
-
-	control, err := nebula.Main(c, false, "e2e-test", l, nil)
-
-	if err != nil {
-		panic(err)
-	}
-
-	return control, vpnNetworks, udpAddr, c
-}
-
 type doneCb func()
 
 func deadline(t *testing.T, seconds time.Duration) doneCb {

e2e/tunnels_test.go

@@ -4,16 +4,12 @@
 package e2e
 
 import (
-	"fmt"
-	"net/netip"
 	"testing"
 	"time"
 
 	"github.com/slackhq/nebula/cert"
 	"github.com/slackhq/nebula/cert_test"
 	"github.com/slackhq/nebula/e2e/router"
-	"github.com/stretchr/testify/assert"
-	"gopkg.in/yaml.v3"
 )
 
 func TestDropInactiveTunnels(t *testing.T) {
@@ -59,262 +55,3 @@ func TestDropInactiveTunnels(t *testing.T) {
 	myControl.Stop()
 	theirControl.Stop()
 }
-
-func TestCertUpgrade(t *testing.T) {
-	// The goal of this test is to ensure the shortest inactivity timeout will close the tunnel on both sides
-	// under ideal conditions
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version1, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	caB, err := ca.MarshalPEM()
-	if err != nil {
-		panic(err)
-	}
-	ca2, _, caKey2, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-
-	ca2B, err := ca2.MarshalPEM()
-	if err != nil {
-		panic(err)
-	}
-	caStr := fmt.Sprintf("%s\n%s", caB, ca2B)
-
-	myCert, _, myPrivKey, _ := cert_test.NewTestCert(cert.Version1, cert.Curve_CURVE25519, ca, caKey, "me", time.Now(), time.Now().Add(5*time.Minute), []netip.Prefix{netip.MustParsePrefix("10.128.0.1/24")}, nil, []string{})
-	_, myCert2Pem := cert_test.NewTestCertDifferentVersion(myCert, cert.Version2, ca2, caKey2)
-
-	theirCert, _, theirPrivKey, _ := cert_test.NewTestCert(cert.Version1, cert.Curve_CURVE25519, ca, caKey, "them", time.Now(), time.Now().Add(5*time.Minute), []netip.Prefix{netip.MustParsePrefix("10.128.0.2/24")}, nil, []string{})
-	theirCert2, _ := cert_test.NewTestCertDifferentVersion(theirCert, cert.Version2, ca2, caKey2)
-
-	myControl, myVpnIpNet, myUdpAddr, myC := newServer([]cert.Certificate{ca, ca2}, []cert.Certificate{myCert}, myPrivKey, m{})
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newServer([]cert.Certificate{ca, ca2}, []cert.Certificate{theirCert, theirCert2}, theirPrivKey, m{})
-
-	// Share our underlay information
-	myControl.InjectLightHouseAddr(theirVpnIpNet[0].Addr(), theirUdpAddr)
-	theirControl.InjectLightHouseAddr(myVpnIpNet[0].Addr(), myUdpAddr)
-
-	// Start the servers
-	myControl.Start()
-	theirControl.Start()
-
-	r := router.NewR(t, myControl, theirControl)
-	defer r.RenderFlow()
-
-	r.Log("Assert the tunnel between me and them works")
-	assertTunnel(t, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), myControl, theirControl, r)
-	r.Log("yay")
-	//todo ???
-	time.Sleep(1 * time.Second)
-	r.FlushAll()
-
-	mc := m{
-		"pki": m{
-			"ca":   caStr,
-			"cert": string(myCert2Pem),
-			"key":  string(myPrivKey),
-		},
-		//"tun": m{"disabled": true},
-		"firewall": myC.Settings["firewall"],
-		//"handshakes": m{
-		//	"try_interval": "1s",
-		//},
-		"listen":  myC.Settings["listen"],
-		"logging": myC.Settings["logging"],
-		"timers":  myC.Settings["timers"],
-	}
-
-	cb, err := yaml.Marshal(mc)
-	if err != nil {
-		panic(err)
-	}
-
-	r.Logf("reload new v2-only config")
-	err = myC.ReloadConfigString(string(cb))
-	assert.NoError(t, err)
-	r.Log("yay, spin until their sees it")
-	waitStart := time.Now()
-	for {
-		assertTunnel(t, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), myControl, theirControl, r)
-		c := theirControl.GetHostInfoByVpnAddr(myVpnIpNet[0].Addr(), false)
-		if c == nil {
-			r.Log("nil")
-		} else {
-			version := c.Cert.Version()
-			r.Logf("version %d", version)
-			if version == cert.Version2 {
-				break
-			}
-		}
-		since := time.Since(waitStart)
-		if since > time.Second*10 {
-			t.Fatal("Cert should be new by now")
-		}
-		time.Sleep(time.Second)
-	}
-
-	r.RenderHostmaps("Final hostmaps", myControl, theirControl)
-
-	myControl.Stop()
-	theirControl.Stop()
-}
-
-func TestCertDowngrade(t *testing.T) {
-	// The goal of this test is to ensure the shortest inactivity timeout will close the tunnel on both sides
-	// under ideal conditions
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version1, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	caB, err := ca.MarshalPEM()
-	if err != nil {
-		panic(err)
-	}
-	ca2, _, caKey2, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-
-	ca2B, err := ca2.MarshalPEM()
-	if err != nil {
-		panic(err)
-	}
-	caStr := fmt.Sprintf("%s\n%s", caB, ca2B)
-
-	myCert, _, myPrivKey, myCertPem := cert_test.NewTestCert(cert.Version1, cert.Curve_CURVE25519, ca, caKey, "me", time.Now(), time.Now().Add(5*time.Minute), []netip.Prefix{netip.MustParsePrefix("10.128.0.1/24")}, nil, []string{})
-	myCert2, _ := cert_test.NewTestCertDifferentVersion(myCert, cert.Version2, ca2, caKey2)
-
-	theirCert, _, theirPrivKey, _ := cert_test.NewTestCert(cert.Version1, cert.Curve_CURVE25519, ca, caKey, "them", time.Now(), time.Now().Add(5*time.Minute), []netip.Prefix{netip.MustParsePrefix("10.128.0.2/24")}, nil, []string{})
-	theirCert2, _ := cert_test.NewTestCertDifferentVersion(theirCert, cert.Version2, ca2, caKey2)
-
-	myControl, myVpnIpNet, myUdpAddr, myC := newServer([]cert.Certificate{ca, ca2}, []cert.Certificate{myCert2}, myPrivKey, m{})
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newServer([]cert.Certificate{ca, ca2}, []cert.Certificate{theirCert, theirCert2}, theirPrivKey, m{})
-
-	// Share our underlay information
-	myControl.InjectLightHouseAddr(theirVpnIpNet[0].Addr(), theirUdpAddr)
-	theirControl.InjectLightHouseAddr(myVpnIpNet[0].Addr(), myUdpAddr)
-
-	// Start the servers
-	myControl.Start()
-	theirControl.Start()
-
-	r := router.NewR(t, myControl, theirControl)
-	defer r.RenderFlow()
-
-	r.Log("Assert the tunnel between me and them works")
-	//assertTunnel(t, theirVpnIpNet[0].Addr(), myVpnIpNet[0].Addr(), theirControl, myControl, r)
-	//r.Log("yay")
-	assertTunnel(t, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), myControl, theirControl, r)
-	r.Log("yay")
-	//todo ???
-	time.Sleep(1 * time.Second)
-	r.FlushAll()
-
-	mc := m{
-		"pki": m{
-			"ca":   caStr,
-			"cert": string(myCertPem),
-			"key":  string(myPrivKey),
-		},
-		"firewall": myC.Settings["firewall"],
-		"listen":   myC.Settings["listen"],
-		"logging":  myC.Settings["logging"],
-		"timers":   myC.Settings["timers"],
-	}
-
-	cb, err := yaml.Marshal(mc)
-	if err != nil {
-		panic(err)
-	}
-
-	r.Logf("reload new v1-only config")
-	err = myC.ReloadConfigString(string(cb))
-	assert.NoError(t, err)
-	r.Log("yay, spin until their sees it")
-	waitStart := time.Now()
-	for {
-		assertTunnel(t, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), myControl, theirControl, r)
-		c := theirControl.GetHostInfoByVpnAddr(myVpnIpNet[0].Addr(), false)
-		c2 := myControl.GetHostInfoByVpnAddr(theirVpnIpNet[0].Addr(), false)
-		if c == nil || c2 == nil {
-			r.Log("nil")
-		} else {
-			version := c.Cert.Version()
-			theirVersion := c2.Cert.Version()
-			r.Logf("version %d,%d", version, theirVersion)
-			if version == cert.Version1 {
-				break
-			}
-		}
-		since := time.Since(waitStart)
-		if since > time.Second*5 {
-			r.Log("it is unusual that the cert is not new yet, but not a failure yet")
-		}
-		if since > time.Second*10 {
-			r.Log("wtf")
-			t.Fatal("Cert should be new by now")
-		}
-		time.Sleep(time.Second)
-	}
-
-	r.RenderHostmaps("Final hostmaps", myControl, theirControl)
-
-	myControl.Stop()
-	theirControl.Stop()
-}
-
-func TestCertMismatchCorrection(t *testing.T) {
-	// The goal of this test is to ensure the shortest inactivity timeout will close the tunnel on both sides
-	// under ideal conditions
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version1, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	ca2, _, caKey2, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-
-	myCert, _, myPrivKey, _ := cert_test.NewTestCert(cert.Version1, cert.Curve_CURVE25519, ca, caKey, "me", time.Now(), time.Now().Add(5*time.Minute), []netip.Prefix{netip.MustParsePrefix("10.128.0.1/24")}, nil, []string{})
-	myCert2, _ := cert_test.NewTestCertDifferentVersion(myCert, cert.Version2, ca2, caKey2)
-
-	theirCert, _, theirPrivKey, _ := cert_test.NewTestCert(cert.Version1, cert.Curve_CURVE25519, ca, caKey, "them", time.Now(), time.Now().Add(5*time.Minute), []netip.Prefix{netip.MustParsePrefix("10.128.0.2/24")}, nil, []string{})
-	theirCert2, _ := cert_test.NewTestCertDifferentVersion(theirCert, cert.Version2, ca2, caKey2)
-
-	myControl, myVpnIpNet, myUdpAddr, _ := newServer([]cert.Certificate{ca, ca2}, []cert.Certificate{myCert2}, myPrivKey, m{})
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newServer([]cert.Certificate{ca, ca2}, []cert.Certificate{theirCert, theirCert2}, theirPrivKey, m{})
-
-	// Share our underlay information
-	myControl.InjectLightHouseAddr(theirVpnIpNet[0].Addr(), theirUdpAddr)
-	theirControl.InjectLightHouseAddr(myVpnIpNet[0].Addr(), myUdpAddr)
-
-	// Start the servers
-	myControl.Start()
-	theirControl.Start()
-
-	r := router.NewR(t, myControl, theirControl)
-	defer r.RenderFlow()
-
-	r.Log("Assert the tunnel between me and them works")
-	//assertTunnel(t, theirVpnIpNet[0].Addr(), myVpnIpNet[0].Addr(), theirControl, myControl, r)
-	//r.Log("yay")
-	assertTunnel(t, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), myControl, theirControl, r)
-	r.Log("yay")
-	//todo ???
-	time.Sleep(1 * time.Second)
-	r.FlushAll()
-
-	waitStart := time.Now()
-	for {
-		assertTunnel(t, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), myControl, theirControl, r)
-		c := theirControl.GetHostInfoByVpnAddr(myVpnIpNet[0].Addr(), false)
-		c2 := myControl.GetHostInfoByVpnAddr(theirVpnIpNet[0].Addr(), false)
-		if c == nil || c2 == nil {
-			r.Log("nil")
-		} else {
-			version := c.Cert.Version()
-			theirVersion := c2.Cert.Version()
-			r.Logf("version %d,%d", version, theirVersion)
-			if version == theirVersion {
-				break
-			}
-		}
-		since := time.Since(waitStart)
-		if since > time.Second*5 {
-			r.Log("wtf")
-		}
-		if since > time.Second*10 {
-			r.Log("wtf")
-			t.Fatal("Cert should be new by now")
-		}
-		time.Sleep(time.Second)
-	}
-
-	r.RenderHostmaps("Final hostmaps", myControl, theirControl)
-
-	myControl.Stop()
-	theirControl.Stop()
-}

firewall.go

@@ -423,7 +423,7 @@ var ErrNoMatchingRule = errors.New("no matching rule in firewall table")
 
 // Drop returns an error if the packet should be dropped, explaining why. It
 // returns nil if the packet should not be dropped.
-func (f *Firewall) Drop(fp firewall.Packet, incoming bool, h *HostInfo, caPool *cert.CAPool, localCache *firewall.ConntrackCache) error {
+func (f *Firewall) Drop(fp firewall.Packet, incoming bool, h *HostInfo, caPool *cert.CAPool, localCache firewall.ConntrackCache) error {
 	// Check if we spoke to this tuple, if we did then allow this packet
 	if f.inConns(fp, h, caPool, localCache) {
 		return nil
@@ -490,10 +490,12 @@ func (f *Firewall) EmitStats() {
 	metrics.GetOrRegisterGauge("firewall.rules.hash", nil).Update(int64(f.GetRuleHashFNV()))
 }
 
-func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool, localCache *firewall.ConntrackCache) bool {
+func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool, localCache firewall.ConntrackCache) bool {
-	if localCache != nil && localCache.Has(fp) {
+	if localCache != nil {
+		if _, ok := localCache[fp]; ok {
 			return true
 		}
+	}
 	conntrack := f.Conntrack
 	conntrack.Lock()
 
@@ -557,7 +559,7 @@ func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool,
 	conntrack.Unlock()
 
 	if localCache != nil {
-		localCache.Add(fp)
+		localCache[fp] = struct{}{}
 	}
 
 	return true

firewall/cache.go

@@ -1,7 +1,6 @@
 package firewall
 
 import (
-	"sync"
 	"sync/atomic"
 	"time"
 
@@ -10,58 +9,13 @@ import (
 
 // ConntrackCache is used as a local routine cache to know if a given flow
 // has been seen in the conntrack table.
-type ConntrackCache struct {
+type ConntrackCache map[Packet]struct{}
-	mu      sync.Mutex
-	entries map[Packet]struct{}
-}
-
-func newConntrackCache() *ConntrackCache {
-	return &ConntrackCache{entries: make(map[Packet]struct{})}
-}
-
-func (c *ConntrackCache) Has(p Packet) bool {
-	if c == nil {
-		return false
-	}
-	c.mu.Lock()
-	_, ok := c.entries[p]
-	c.mu.Unlock()
-	return ok
-}
-
-func (c *ConntrackCache) Add(p Packet) {
-	if c == nil {
-		return
-	}
-	c.mu.Lock()
-	c.entries[p] = struct{}{}
-	c.mu.Unlock()
-}
-
-func (c *ConntrackCache) Len() int {
-	if c == nil {
-		return 0
-	}
-	c.mu.Lock()
-	l := len(c.entries)
-	c.mu.Unlock()
-	return l
-}
-
-func (c *ConntrackCache) Reset(capHint int) {
-	if c == nil {
-		return
-	}
-	c.mu.Lock()
-	c.entries = make(map[Packet]struct{}, capHint)
-	c.mu.Unlock()
-}
 
 type ConntrackCacheTicker struct {
 	cacheV    uint64
 	cacheTick atomic.Uint64
 
-	cache *ConntrackCache
+	cache ConntrackCache
 }
 
 func NewConntrackCacheTicker(d time.Duration) *ConntrackCacheTicker {
@@ -69,7 +23,9 @@ func NewConntrackCacheTicker(d time.Duration) *ConntrackCacheTicker {
 		return nil
 	}
 
-	c := &ConntrackCacheTicker{cache: newConntrackCache()}
+	c := &ConntrackCacheTicker{
+		cache: ConntrackCache{},
+	}
 
 	go c.tick(d)
 
@@ -85,17 +41,17 @@ func (c *ConntrackCacheTicker) tick(d time.Duration) {
 
 // Get checks if the cache ticker has moved to the next version before returning
 // the map. If it has moved, we reset the map.
-func (c *ConntrackCacheTicker) Get(l *logrus.Logger) *ConntrackCache {
+func (c *ConntrackCacheTicker) Get(l *logrus.Logger) ConntrackCache {
 	if c == nil {
 		return nil
 	}
 	if tick := c.cacheTick.Load(); tick != c.cacheV {
 		c.cacheV = tick
-		if ll := c.cache.Len(); ll > 0 {
+		if ll := len(c.cache); ll > 0 {
 			if l.Level == logrus.DebugLevel {
 				l.WithField("len", ll).Debug("resetting conntrack cache")
 			}
-			c.cache.Reset(ll)
+			c.cache = make(ConntrackCache, ll)
 		}
 	}
 

go.mod

@@ -29,11 +29,11 @@ require (
 	golang.org/x/sys v0.37.0
 	golang.org/x/term v0.36.0
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2
-	golang.zx2c4.com/wireguard v0.0.0-20230325221338-052af4a8072b
+	golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb
 	golang.zx2c4.com/wireguard/windows v0.5.3
 	google.golang.org/protobuf v1.36.8
 	gopkg.in/yaml.v3 v3.0.1
-	gvisor.dev/gvisor v0.0.0-20240423190808-9d7a357edefe
+	gvisor.dev/gvisor v0.0.0-20250503011706-39ed1f5ac29c
 )
 
 require (
@@ -49,6 +49,6 @@ require (
 	github.com/vishvananda/netns v0.0.5 // indirect
 	go.yaml.in/yaml/v2 v2.4.2 // indirect
 	golang.org/x/mod v0.24.0 // indirect
-	golang.org/x/time v0.5.0 // indirect
+	golang.org/x/time v0.7.0 // indirect
 	golang.org/x/tools v0.33.0 // indirect
 )

go.sum

@@ -215,8 +215,8 @@ golang.org/x/term v0.36.0/go.mod h1:Qu394IJq6V6dCBRgwqshf3mPF85AqzYEzofzRdZkWss=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/time v0.5.0 h1:o7cqy6amK/52YcAKIPlM3a+Fpj35zvRj2TP+e1xFSfk=
+golang.org/x/time v0.7.0 h1:ntUhktv3OPE6TgYxXWv9vKvUSJyIFJlyohwbkEwPrKQ=
-golang.org/x/time v0.5.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
+golang.org/x/time v0.7.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
@@ -230,8 +230,8 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 h1:B82qJJgjvYKsXS9jeunTOisW56dUokqW/FOteYJJ/yg=
 golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2/go.mod h1:deeaetjYA+DHMHg+sMSMI58GrEteJUUzzw7en6TJQcI=
-golang.zx2c4.com/wireguard v0.0.0-20230325221338-052af4a8072b h1:J1CaxgLerRR5lgx3wnr6L04cJFbWoceSK9JWBdglINo=
+golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb h1:whnFRlWMcXI9d+ZbWg+4sHnLp52d5yiIPUxMBSt4X9A=
-golang.zx2c4.com/wireguard v0.0.0-20230325221338-052af4a8072b/go.mod h1:tqur9LnfstdR9ep2LaJT4lFUl0EjlHtge+gAjmsHUG4=
+golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb/go.mod h1:rpwXGsirqLqN2L0JDJQlwOboGHmptD5ZD6T2VmcqhTw=
 golang.zx2c4.com/wireguard/windows v0.5.3 h1:On6j2Rpn3OEMXqBq00QEDC7bWSZrPIHKIus8eIuExIE=
 golang.zx2c4.com/wireguard/windows v0.5.3/go.mod h1:9TEe8TJmtwyQebdFwAkEWOPr3prrtqm+REGFifP60hI=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
@@ -257,5 +257,5 @@ gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gvisor.dev/gvisor v0.0.0-20240423190808-9d7a357edefe h1:fre4i6mv4iBuz5lCMOzHD1rH1ljqHWSICFmZRbbgp3g=
+gvisor.dev/gvisor v0.0.0-20250503011706-39ed1f5ac29c h1:m/r7OM+Y2Ty1sgBQ7Qb27VgIMBW8ZZhT4gLnUyDIhzI=
-gvisor.dev/gvisor v0.0.0-20240423190808-9d7a357edefe/go.mod h1:sxc3Uvk/vHcd3tj7/DHVBoR5wvWT/MmRq2pj7HRJnwU=
+gvisor.dev/gvisor v0.0.0-20250503011706-39ed1f5ac29c/go.mod h1:3r5CMtNQMKIvBlrmM9xWUNamjKBYPOWyXOjmg5Kts3g=

handshake_ix.go

@@ -23,19 +23,15 @@ func ixHandshakeStage0(f *Interface, hh *HandshakeHostInfo) bool {
 		return false
 	}
 
+	// If we're connecting to a v6 address we must use a v2 cert
 	cs := f.pki.getCertState()
 	v := cs.initiatingVersion
-	if hh.initiatingVersionOverride != cert.VersionPre1 {
-		v = hh.initiatingVersionOverride
-	} else if v < cert.Version2 {
-		// If we're connecting to a v6 address we should encourage use of a V2 cert
 	for _, a := range hh.hostinfo.vpnAddrs {
 		if a.Is6() {
 			v = cert.Version2
 			break
 		}
 	}
-	}
 
 	crt := cs.getCertificate(v)
 	if crt == nil {
@@ -52,7 +48,6 @@ func ixHandshakeStage0(f *Interface, hh *HandshakeHostInfo) bool {
 			WithField("handshake", m{"stage": 0, "style": "ix_psk0"}).
 			WithField("certVersion", v).
 			Error("Unable to handshake with host because no certificate handshake bytes is available")
-		return false
 	}
 
 	ci, err := NewConnectionState(f.l, cs, crt, true, noise.HandshakeIX)
@@ -108,7 +103,6 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 			WithField("handshake", m{"stage": 0, "style": "ix_psk0"}).
 			WithField("certVersion", cs.initiatingVersion).
 			Error("Unable to handshake with host because no certificate is available")
-		return
 	}
 
 	ci, err := NewConnectionState(f.l, cs, crt, false, noise.HandshakeIX)
@@ -149,8 +143,8 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 
 	remoteCert, err := f.pki.GetCAPool().VerifyCertificate(time.Now(), rc)
 	if err != nil {
-		fp, fperr := rc.Fingerprint()
+		fp, err := rc.Fingerprint()
-		if fperr != nil {
+		if err != nil {
 			fp = "<error generating certificate fingerprint>"
 		}
 
@@ -169,19 +163,16 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 
 	if remoteCert.Certificate.Version() != ci.myCert.Version() {
 		// We started off using the wrong certificate version, lets see if we can match the version that was sent to us
-		myCertOtherVersion := cs.getCertificate(remoteCert.Certificate.Version())
+		rc := cs.getCertificate(remoteCert.Certificate.Version())
-		if myCertOtherVersion == nil {
+		if rc == nil {
-			if f.l.Level >= logrus.DebugLevel {
+			f.l.WithError(err).WithField("udpAddr", addr).
-				f.l.WithError(err).WithFields(m{
+				WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).WithField("cert", remoteCert).
-					"udpAddr":   addr,
+				Info("Unable to handshake with host due to missing certificate version")
-					"handshake": m{"stage": 1, "style": "ix_psk0"},
+			return
-					"cert":      remoteCert,
-				}).Debug("Might be unable to handshake with host due to missing certificate version")
 		}
-		} else {
+
 		// Record the certificate we are actually using
-			ci.myCert = myCertOtherVersion
+		ci.myCert = rc
-		}
 	}
 
 	if len(remoteCert.Certificate.Networks()) == 0 {

handshake_manager.go

@@ -70,7 +70,6 @@ type HandshakeHostInfo struct {
 
 	startTime   time.Time        // Time that we first started trying with this handshake
 	ready       bool             // Is the handshake ready
-	initiatingVersionOverride cert.Version     // Should we use a non-default cert version for this handshake?
 	counter     int64            // How many attempts have we made so far
 	lastRemotes []netip.AddrPort // Remotes that we sent to during the previous attempt
 	packetStore []*cachedPacket  // A set of packets to be transmitted once the handshake completes

inside.go

@@ -2,18 +2,16 @@ package nebula
 
 import (
 	"net/netip"
-	"unsafe"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/firewall"
 	"github.com/slackhq/nebula/header"
 	"github.com/slackhq/nebula/iputil"
 	"github.com/slackhq/nebula/noiseutil"
-	"github.com/slackhq/nebula/overlay"
 	"github.com/slackhq/nebula/routing"
 )
 
-func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet, nb, out []byte, q int, localCache *firewall.ConntrackCache) {
+func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet, nb, out []byte, q int, localCache firewall.ConntrackCache) {
 	err := newPacket(packet, false, fwPacket)
 	if err != nil {
 		if f.l.Level >= logrus.DebugLevel {
@@ -35,8 +33,7 @@ func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet
 		// routes packets from the Nebula addr to the Nebula addr through the Nebula
 		// TUN device.
 		if immediatelyForwardToSelf {
-			_, err := f.readers[q].Write(packet)
+			if err := f.writeTun(q, packet); err != nil {
-			if err != nil {
 				f.l.WithError(err).Error("Failed to forward to tun")
 			}
 		}
@@ -93,8 +90,7 @@ func (f *Interface) rejectInside(packet []byte, out []byte, q int) {
 		return
 	}
 
-	_, err := f.readers[q].Write(out)
+	if err := f.writeTun(q, out); err != nil {
-	if err != nil {
 		f.l.WithError(err).Error("Failed to write to tun")
 	}
 }
@@ -337,21 +333,9 @@ func (f *Interface) sendNoMetrics(t header.MessageType, st header.MessageSubType
 	if ci.eKey == nil {
 		return
 	}
-	target := remote
+	useRelay := !remote.IsValid() && !hostinfo.remote.IsValid()
-	if !target.IsValid() {
-		target = hostinfo.remote
-	}
-	useRelay := !target.IsValid()
 	fullOut := out
 
-	var pkt *overlay.Packet
-	if !useRelay && f.batches.Enabled() {
-		pkt = f.batches.newPacket()
-		if pkt != nil {
-			out = pkt.Payload()[:0]
-		}
-	}
-
 	if useRelay {
 		if len(out) < header.Len {
 			// out always has a capacity of mtu, but not always a length greater than the header.Len.
@@ -385,62 +369,31 @@ func (f *Interface) sendNoMetrics(t header.MessageType, st header.MessageSubType
 	}
 
 	var err error
-	if len(p) > 0 && slicesOverlap(out, p) {
-		tmp := make([]byte, len(p))
-		copy(tmp, p)
-		p = tmp
-	}
 	out, err = ci.eKey.EncryptDanger(out, out, p, c, nb)
 	if noiseutil.EncryptLockNeeded {
 		ci.writeLock.Unlock()
 	}
 	if err != nil {
-		if pkt != nil {
-			pkt.Release()
-		}
 		hostinfo.logger(f.l).WithError(err).
-			WithField("udpAddr", target).WithField("counter", c).
+			WithField("udpAddr", remote).WithField("counter", c).
 			WithField("attemptedCounter", c).
 			Error("Failed to encrypt outgoing packet")
 		return
 	}
 
-	if target.IsValid() {
+	if remote.IsValid() {
-		if pkt != nil {
+		err = f.writers[q].WriteTo(out, remote)
-			pkt.Len = len(out)
+		if err != nil {
-			if f.l.Level >= logrus.DebugLevel {
+			hostinfo.logger(f.l).WithError(err).
-				f.l.WithFields(logrus.Fields{
+				WithField("udpAddr", remote).Error("Failed to write outgoing packet")
-					"queue":        q,
-					"dest":         target,
-					"payload_len":  pkt.Len,
-					"use_batches":  true,
-					"remote_index": hostinfo.remoteIndexId,
-				}).Debug("enqueueing packet to UDP batch queue")
 		}
-			if f.tryQueuePacket(q, pkt, target) {
+	} else if hostinfo.remote.IsValid() {
-				return
+		err = f.writers[q].WriteTo(out, hostinfo.remote)
+		if err != nil {
+			hostinfo.logger(f.l).WithError(err).
+				WithField("udpAddr", remote).Error("Failed to write outgoing packet")
 		}
-			if f.l.Level >= logrus.DebugLevel {
+	} else {
-				f.l.WithFields(logrus.Fields{
-					"queue": q,
-					"dest":  target,
-				}).Debug("failed to enqueue packet; falling back to immediate send")
-			}
-			f.writeImmediatePacket(q, pkt, target, hostinfo)
-			return
-		}
-		if f.tryQueueDatagram(q, out, target) {
-			return
-		}
-		f.writeImmediate(q, out, target, hostinfo)
-		return
-	}
-
-	// fall back to relay path
-	if pkt != nil {
-		pkt.Release()
-	}
-
 		// Try to send via a relay
 		for _, relayIP := range hostinfo.relayState.CopyRelayIps() {
 			relayHostInfo, relay, err := f.hostMap.QueryVpnAddrsRelayFor(hostinfo.vpnAddrs, relayIP)
@@ -453,17 +406,4 @@ func (f *Interface) sendNoMetrics(t header.MessageType, st header.MessageSubType
 			break
 		}
 	}
-
-// slicesOverlap reports whether the two byte slices share any portion of memory.
-// cipher.AEAD.Seal requires plaintext and dst to live in disjoint regions.
-func slicesOverlap(a, b []byte) bool {
-	if len(a) == 0 || len(b) == 0 {
-		return false
-	}
-
-	aStart := uintptr(unsafe.Pointer(&a[0]))
-	aEnd := aStart + uintptr(len(a))
-	bStart := uintptr(unsafe.Pointer(&b[0]))
-	bEnd := bStart + uintptr(len(b))
-	return aStart < bEnd && bStart < aEnd
 }

interface.go

@@ -8,7 +8,6 @@ import (
 	"net/netip"
 	"os"
 	"runtime"
-	"strings"
 	"sync/atomic"
 	"time"
 
@@ -22,13 +21,7 @@ import (
 	"github.com/slackhq/nebula/udp"
 )
 
-const (
+const mtu = 9001
-	mtu                          = 9001
-	defaultGSOFlushInterval      = 150 * time.Microsecond
-	defaultBatchQueueDepthFactor = 4
-	defaultGSOMaxSegments        = 8
-	maxKernelGSOSegments         = 64
-)
 
 type InterfaceConfig struct {
 	HostMap            *HostMap
@@ -43,9 +36,6 @@ type InterfaceConfig struct {
 	connectionManager  *connectionManager
 	DropLocalBroadcast bool
 	DropMulticast      bool
-	EnableGSO          bool
-	EnableGRO          bool
-	GSOMaxSegments     int
 	routines           int
 	MessageMetrics     *MessageMetrics
 	version            string
@@ -57,8 +47,7 @@ type InterfaceConfig struct {
 	reQueryWait     time.Duration
 
 	ConntrackCacheTimeout time.Duration
-	BatchFlushInterval    time.Duration
+	batchSize             int
-	BatchQueueDepth       int
 	l                     *logrus.Logger
 }
 
@@ -96,20 +85,10 @@ type Interface struct {
 	version     string
 
 	conntrackCacheTimeout time.Duration
-	batchQueueDepth       int
+	batchSize             int
-	enableGSO             bool
-	enableGRO             bool
-	gsoMaxSegments        int
-	batchUDPQueueGauge    metrics.Gauge
-	batchUDPFlushCounter  metrics.Counter
-	batchTunQueueGauge    metrics.Gauge
-	batchTunFlushCounter  metrics.Counter
-	batchFlushInterval    atomic.Int64
-	sendSem               chan struct{}
 
 	writers []udp.Conn
 	readers []io.ReadWriteCloser
-	batches batchPipelines
 
 	metricHandshakes    metrics.Histogram
 	messageMetrics      *MessageMetrics
@@ -133,6 +112,16 @@ type EncWriter interface {
 	GetCertState() *CertState
 }
 
+// BatchReader is an interface for readers that support vectorized packet reading
+type BatchReader interface {
+	BatchRead(buffers [][]byte, sizes []int) (int, error)
+}
+
+// BatchWriter is an interface for writers that support vectorized packet writing
+type BatchWriter interface {
+	BatchWrite([][]byte) (int, error)
+}
+
 type sendRecvErrorConfig uint8
 
 const (
@@ -184,22 +173,6 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 		return nil, errors.New("no connection manager")
 	}
 
-	if c.GSOMaxSegments <= 0 {
-		c.GSOMaxSegments = defaultGSOMaxSegments
-	}
-	if c.GSOMaxSegments > maxKernelGSOSegments {
-		c.GSOMaxSegments = maxKernelGSOSegments
-	}
-	if c.BatchQueueDepth <= 0 {
-		c.BatchQueueDepth = c.routines * defaultBatchQueueDepthFactor
-	}
-	if c.BatchFlushInterval < 0 {
-		c.BatchFlushInterval = 0
-	}
-	if c.BatchFlushInterval == 0 && c.EnableGSO {
-		c.BatchFlushInterval = defaultGSOFlushInterval
-	}
-
 	cs := c.pki.getCertState()
 	ifce := &Interface{
 		pki:                   c.pki,
@@ -225,10 +198,7 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 		relayManager:          c.relayManager,
 		connectionManager:     c.connectionManager,
 		conntrackCacheTimeout: c.ConntrackCacheTimeout,
-		batchQueueDepth:       c.BatchQueueDepth,
+		batchSize:             c.batchSize,
-		enableGSO:             c.EnableGSO,
-		enableGRO:             c.EnableGRO,
-		gsoMaxSegments:        c.GSOMaxSegments,
 
 		metricHandshakes: metrics.GetOrRegisterHistogram("handshakes", nil, metrics.NewExpDecaySample(1028, 0.015)),
 		messageMetrics:   c.MessageMetrics,
@@ -241,25 +211,8 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 	}
 
 	ifce.tryPromoteEvery.Store(c.tryPromoteEvery)
-	ifce.batchUDPQueueGauge = metrics.GetOrRegisterGauge("batch.udp.queue_depth", nil)
-	ifce.batchUDPFlushCounter = metrics.GetOrRegisterCounter("batch.udp.flushes", nil)
-	ifce.batchTunQueueGauge = metrics.GetOrRegisterGauge("batch.tun.queue_depth", nil)
-	ifce.batchTunFlushCounter = metrics.GetOrRegisterCounter("batch.tun.flushes", nil)
-	ifce.batchFlushInterval.Store(int64(c.BatchFlushInterval))
-	ifce.sendSem = make(chan struct{}, c.routines)
-	ifce.batches.init(c.Inside, c.routines, c.BatchQueueDepth, c.GSOMaxSegments)
 	ifce.reQueryEvery.Store(c.reQueryEvery)
 	ifce.reQueryWait.Store(int64(c.reQueryWait))
-	if c.l.Level >= logrus.DebugLevel {
-		c.l.WithFields(logrus.Fields{
-			"enableGSO":       c.EnableGSO,
-			"enableGRO":       c.EnableGRO,
-			"gsoMaxSegments":  c.GSOMaxSegments,
-			"batchQueueDepth": c.BatchQueueDepth,
-			"batchFlush":      c.BatchFlushInterval,
-			"batching":        ifce.batches.Enabled(),
-		}).Debug("initialized batch pipelines")
-	}
 
 	ifce.connectionManager.intf = ifce
 
@@ -308,18 +261,6 @@ func (f *Interface) run() {
 		go f.listenOut(i)
 	}
 
-	if f.l.Level >= logrus.DebugLevel {
-		f.l.WithField("batching", f.batches.Enabled()).Debug("starting interface run loops")
-	}
-
-	if f.batches.Enabled() {
-		for i := 0; i < f.routines; i++ {
-			go f.runInsideBatchWorker(i)
-			go f.runTunWriteQueue(i)
-			go f.runSendQueue(i)
-		}
-	}
-
 	// Launch n queues to read packets from tun dev
 	for i := 0; i < f.routines; i++ {
 		go f.listenIn(f.readers[i], i)
@@ -341,7 +282,7 @@ func (f *Interface) listenOut(i int) {
 	plaintext := make([]byte, udp.MTU)
 	h := &header.H{}
 	fwPacket := &firewall.Packet{}
-	nb := make([]byte, 12, 12)
+	nb := make([]byte, 12)
 
 	li.ListenOut(func(fromUdpAddr netip.AddrPort, payload []byte) {
 		f.readOutsidePackets(fromUdpAddr, nil, plaintext[:0], payload, h, fwPacket, lhh, nb, i, ctCache.Get(f.l))
@@ -351,17 +292,16 @@ func (f *Interface) listenOut(i int) {
 func (f *Interface) listenIn(reader io.ReadWriteCloser, i int) {
 	runtime.LockOSThread()
 
-	if f.batches.Enabled() {
+	// Check if reader supports batch operations
-		if br, ok := reader.(overlay.BatchReader); ok {
+	if batchReader, ok := reader.(BatchReader); ok {
-			f.listenInBatchLocked(reader, br, i)
+		err := f.listenInBatch(batchReader, i)
+		if err != nil {
+			f.l.WithError(err).Error("Fatal error in batch packet reader, exiting goroutine")
+		}
 		return
 	}
-	}
 
-	f.listenInLegacyLocked(reader, i)
+	// Fall back to single-packet mode
-}
-
-func (f *Interface) listenInLegacyLocked(reader io.ReadWriteCloser, i int) {
 	packet := make([]byte, mtu)
 	out := make([]byte, mtu)
 	fwPacket := &firewall.Packet{}
@@ -376,588 +316,83 @@ func (f *Interface) listenInLegacyLocked(reader io.ReadWriteCloser, i int) {
 				return
 			}
 
-			f.l.WithError(err).Error("Error while reading outbound packet")
+			f.l.WithError(err).Error("Fatal error while reading outbound packet, exiting goroutine")
-			// This only seems to happen when something fatal happens to the fd, so exit.
+			return
-			os.Exit(2)
 		}
 
 		f.consumeInsidePacket(packet[:n], fwPacket, nb, out, i, conntrackCache.Get(f.l))
 	}
 }
 
-func (f *Interface) listenInBatchLocked(raw io.ReadWriteCloser, reader overlay.BatchReader, i int) {
+// listenInBatch handles vectorized packet reading for improved performance
-	pool := f.batches.Pool()
+func (f *Interface) listenInBatch(reader BatchReader, i int) error {
-	if pool == nil {
+	// Allocate per-packet state and buffers for batch reading
-		f.l.Warn("batch pipeline enabled without an allocated pool; falling back to single-packet reads")
+	batchSize := f.batchSize
-		f.listenInLegacyLocked(raw, i)
+	if batchSize <= 0 {
-		return
+		batchSize = 64 // Fallback to default if not configured
+	}
+	fwPackets := make([]*firewall.Packet, batchSize)
+	outBuffers := make([][]byte, batchSize)
+	nbBuffers := make([][]byte, batchSize)
+	packets := make([][]byte, batchSize)
+	sizes := make([]int, batchSize)
+
+	for j := 0; j < batchSize; j++ {
+		fwPackets[j] = &firewall.Packet{}
+		outBuffers[j] = make([]byte, mtu)
+		nbBuffers[j] = make([]byte, 12)
+		packets[j] = make([]byte, mtu)
 	}
 
-	for {
-		packets, err := reader.ReadIntoBatch(pool)
-		if err != nil {
-			if errors.Is(err, os.ErrClosed) && f.closed.Load() {
-				return
-			}
-
-			if isVirtioHeadroomError(err) {
-				f.l.WithError(err).Warn("Batch reader fell back due to tun headroom issue")
-				f.listenInLegacyLocked(raw, i)
-				return
-			}
-
-			f.l.WithError(err).Error("Error while reading outbound packet batch")
-			os.Exit(2)
-		}
-
-		if len(packets) == 0 {
-			continue
-		}
-
-		for _, pkt := range packets {
-			if pkt == nil {
-				continue
-			}
-			if !f.batches.enqueueRx(i, pkt) {
-				pkt.Release()
-			}
-		}
-	}
-}
-
-func (f *Interface) runInsideBatchWorker(i int) {
-	queue := f.batches.rxQueue(i)
-	if queue == nil {
-		return
-	}
-
-	out := make([]byte, mtu)
-	fwPacket := &firewall.Packet{}
-	nb := make([]byte, 12, 12)
 	conntrackCache := firewall.NewConntrackCacheTicker(f.conntrackCacheTimeout)
 
-	for pkt := range queue {
-		if pkt == nil {
-			continue
-		}
-		f.consumeInsidePacket(pkt.Payload(), fwPacket, nb, out, i, conntrackCache.Get(f.l))
-		pkt.Release()
-	}
-}
-
-func (f *Interface) runSendQueue(i int) {
-	queue := f.batches.txQueue(i)
-	if queue == nil {
-		if f.l.Level >= logrus.DebugLevel {
-			f.l.WithField("queue", i).Debug("tx queue not initialized; batching disabled for writer")
-		}
-		return
-	}
-	writer := f.writerForIndex(i)
-	if writer == nil {
-		if f.l.Level >= logrus.DebugLevel {
-			f.l.WithField("queue", i).Debug("no UDP writer for batch queue")
-		}
-		return
-	}
-	if f.l.Level >= logrus.DebugLevel {
-		f.l.WithField("queue", i).Debug("send queue worker started")
-	}
-	defer func() {
-		if f.l.Level >= logrus.WarnLevel {
-			f.l.WithField("queue", i).Warn("send queue worker exited")
-		}
-	}()
-
-	batchCap := f.batches.batchSizeHint()
-	if batchCap <= 0 {
-		batchCap = 1
-	}
-	gsoLimit := f.effectiveGSOMaxSegments()
-	if gsoLimit > batchCap {
-		batchCap = gsoLimit
-	}
-	pending := make([]queuedDatagram, 0, batchCap)
-	var (
-		flushTimer *time.Timer
-		flushC     <-chan time.Time
-	)
-	dispatch := func(reason string, timerFired bool) {
-		if len(pending) == 0 {
-			return
-		}
-		batch := pending
-		f.flushAndReleaseBatch(i, writer, batch, reason)
-		for idx := range batch {
-			batch[idx] = queuedDatagram{}
-		}
-		pending = pending[:0]
-		if flushTimer != nil {
-			if !timerFired {
-				if !flushTimer.Stop() {
-					select {
-					case <-flushTimer.C:
-					default:
-					}
-				}
-			}
-			flushTimer = nil
-			flushC = nil
-		}
-	}
-	armTimer := func() {
-		delay := f.currentBatchFlushInterval()
-		if delay <= 0 {
-			dispatch("nogso", false)
-			return
-		}
-		if flushTimer == nil {
-			flushTimer = time.NewTimer(delay)
-			flushC = flushTimer.C
-		}
-	}
-
 	for {
-		select {
+		n, err := reader.BatchRead(packets, sizes)
-		case d := <-queue:
+		if err != nil {
-			if d.packet == nil {
+			if errors.Is(err, os.ErrClosed) && f.closed.Load() {
-				continue
-			}
-			if f.l.Level >= logrus.DebugLevel {
-				f.l.WithFields(logrus.Fields{
-					"queue":       i,
-					"payload_len": d.packet.Len,
-					"dest":        d.addr,
-				}).Debug("send queue received packet")
-			}
-			pending = append(pending, d)
-			if gsoLimit > 0 && len(pending) >= gsoLimit {
-				dispatch("gso", false)
-				continue
-			}
-			if len(pending) >= cap(pending) {
-				dispatch("cap", false)
-				continue
-			}
-			armTimer()
-			f.observeUDPQueueLen(i)
-		case <-flushC:
-			dispatch("timer", true)
-		}
-	}
-}
-
-func (f *Interface) runTunWriteQueue(i int) {
-	queue := f.batches.tunQueue(i)
-	if queue == nil {
-		return
-	}
-	writer := f.batches.inside
-	if writer == nil {
-		return
-	}
-	requiredHeadroom := writer.BatchHeadroom()
-
-	batchCap := f.batches.batchSizeHint()
-	if batchCap <= 0 {
-		batchCap = 1
-	}
-	pending := make([]*overlay.Packet, 0, batchCap)
-	var (
-		flushTimer *time.Timer
-		flushC     <-chan time.Time
-	)
-	flush := func(reason string, timerFired bool) {
-		if len(pending) == 0 {
-			return
-		}
-		valid := pending[:0]
-		for idx := range pending {
-			if !f.ensurePacketHeadroom(&pending[idx], requiredHeadroom, i, reason) {
-				pending[idx] = nil
-				continue
-			}
-			if pending[idx] != nil {
-				valid = append(valid, pending[idx])
-			}
-		}
-		if len(valid) > 0 {
-			if _, err := writer.WriteBatch(valid); err != nil {
-				f.l.WithError(err).
-					WithField("queue", i).
-					WithField("reason", reason).
-					Warn("Failed to write tun batch")
-				for _, pkt := range valid {
-					if pkt != nil {
-						f.writePacketToTun(i, pkt)
-					}
-				}
-			}
-		}
-		pending = pending[:0]
-		if flushTimer != nil {
-			if !timerFired {
-				if !flushTimer.Stop() {
-					select {
-					case <-flushTimer.C:
-					default:
-					}
-				}
-			}
-			flushTimer = nil
-			flushC = nil
-		}
-	}
-	armTimer := func() {
-		delay := f.currentBatchFlushInterval()
-		if delay <= 0 {
-			return
-		}
-		if flushTimer == nil {
-			flushTimer = time.NewTimer(delay)
-			flushC = flushTimer.C
-		}
-	}
-
-	for {
-		select {
-		case pkt := <-queue:
-			if pkt == nil {
-				continue
-			}
-			if f.ensurePacketHeadroom(&pkt, requiredHeadroom, i, "queue") {
-				pending = append(pending, pkt)
-			}
-			if len(pending) >= cap(pending) {
-				flush("cap", false)
-				continue
-			}
-			armTimer()
-			f.observeTunQueueLen(i)
-		case <-flushC:
-			flush("timer", true)
-		}
-	}
-}
-
-func (f *Interface) flushAndReleaseBatch(index int, writer udp.Conn, batch []queuedDatagram, reason string) {
-	if len(batch) == 0 {
-		return
-	}
-	f.flushDatagrams(index, writer, batch, reason)
-	for idx := range batch {
-		if batch[idx].packet != nil {
-			batch[idx].packet.Release()
-			batch[idx].packet = nil
-		}
-	}
-	if f.batchUDPFlushCounter != nil {
-		f.batchUDPFlushCounter.Inc(int64(len(batch)))
-	}
-}
-
-func (f *Interface) flushDatagrams(index int, writer udp.Conn, batch []queuedDatagram, reason string) {
-	if len(batch) == 0 {
-		return
-	}
-	if f.l.Level >= logrus.DebugLevel {
-		f.l.WithFields(logrus.Fields{
-			"writer":  index,
-			"reason":  reason,
-			"pending": len(batch),
-		}).Debug("udp batch flush summary")
-	}
-	maxSeg := f.effectiveGSOMaxSegments()
-	if bw, ok := writer.(udp.BatchConn); ok {
-		chunkCap := maxSeg
-		if chunkCap <= 0 {
-			chunkCap = len(batch)
-		}
-		chunk := make([]udp.Datagram, 0, chunkCap)
-		var (
-			currentAddr netip.AddrPort
-			segments    int
-		)
-		flushChunk := func() {
-			if len(chunk) == 0 {
-				return
-			}
-			if f.l.Level >= logrus.DebugLevel {
-				f.l.WithFields(logrus.Fields{
-					"writer":        index,
-					"segments":      len(chunk),
-					"dest":          chunk[0].Addr,
-					"reason":        reason,
-					"pending_total": len(batch),
-				}).Debug("flushing UDP batch")
-			}
-			if err := bw.WriteBatch(chunk); err != nil {
-				f.l.WithError(err).
-					WithField("writer", index).
-					WithField("reason", reason).
-					Warn("Failed to write UDP batch")
-			}
-			chunk = chunk[:0]
-			segments = 0
-		}
-		for _, item := range batch {
-			if item.packet == nil || !item.addr.IsValid() {
-				continue
-			}
-			payload := item.packet.Payload()[:item.packet.Len]
-			if segments == 0 {
-				currentAddr = item.addr
-			}
-			if item.addr != currentAddr || (maxSeg > 0 && segments >= maxSeg) {
-				flushChunk()
-				currentAddr = item.addr
-			}
-			chunk = append(chunk, udp.Datagram{Payload: payload, Addr: item.addr})
-			segments++
-		}
-		flushChunk()
-		return
-	}
-	for _, item := range batch {
-		if item.packet == nil || !item.addr.IsValid() {
-			continue
-		}
-		if f.l.Level >= logrus.DebugLevel {
-			f.l.WithFields(logrus.Fields{
-				"writer":   index,
-				"reason":   reason,
-				"dest":     item.addr,
-				"segments": 1,
-			}).Debug("flushing UDP batch")
-		}
-		if err := writer.WriteTo(item.packet.Payload()[:item.packet.Len], item.addr); err != nil {
-			f.l.WithError(err).
-				WithField("writer", index).
-				WithField("udpAddr", item.addr).
-				WithField("reason", reason).
-				Warn("Failed to write UDP packet")
-		}
-	}
-}
-
-func (f *Interface) tryQueueDatagram(q int, buf []byte, addr netip.AddrPort) bool {
-	if !addr.IsValid() || !f.batches.Enabled() {
-		return false
-	}
-	pkt := f.batches.newPacket()
-	if pkt == nil {
-		return false
-	}
-	payload := pkt.Payload()
-	if len(payload) < len(buf) {
-		pkt.Release()
-		return false
-	}
-	copy(payload, buf)
-	pkt.Len = len(buf)
-	if f.batches.enqueueTx(q, pkt, addr) {
-		f.observeUDPQueueLen(q)
-		return true
-	}
-	pkt.Release()
-	return false
-}
-
-func (f *Interface) writerForIndex(i int) udp.Conn {
-	if i < 0 || i >= len(f.writers) {
 				return nil
 			}
-	return f.writers[i]
+
+			return fmt.Errorf("error while batch reading outbound packets: %w", err)
 		}
 
-func (f *Interface) writeImmediate(q int, buf []byte, addr netip.AddrPort, hostinfo *HostInfo) {
+		// Process each packet in the batch
-	writer := f.writerForIndex(q)
+		cache := conntrackCache.Get(f.l)
-	if writer == nil {
+		for idx := 0; idx < n; idx++ {
-		f.l.WithField("udpAddr", addr).
+			if sizes[idx] > 0 {
-			WithField("writer", q).
+				// Use modulo to reuse fw packet state if batch is larger than our pre-allocated state
-			Error("Failed to write outgoing packet: no writer available")
+				stateIdx := idx % len(fwPackets)
-		return
+				f.consumeInsidePacket(packets[idx][:sizes[idx]], fwPackets[stateIdx], nbBuffers[stateIdx], outBuffers[stateIdx], i, cache)
+			}
 		}
-	if err := writer.WriteTo(buf, addr); err != nil {
-		hostinfo.logger(f.l).
-			WithError(err).
-			WithField("udpAddr", addr).
-			Error("Failed to write outgoing packet")
 	}
 }
 
-func (f *Interface) tryQueuePacket(q int, pkt *overlay.Packet, addr netip.AddrPort) bool {
+// writeTunBatch attempts to write multiple packets to the TUN device using batch operations if supported
-	if pkt == nil || !addr.IsValid() || !f.batches.Enabled() {
+func (f *Interface) writeTunBatch(q int, packets [][]byte) error {
-		return false
+	if len(packets) == 0 {
-	}
-	if f.batches.enqueueTx(q, pkt, addr) {
-		f.observeUDPQueueLen(q)
-		return true
-	}
-	return false
-}
-
-func (f *Interface) writeImmediatePacket(q int, pkt *overlay.Packet, addr netip.AddrPort, hostinfo *HostInfo) {
-	if pkt == nil {
-		return
-	}
-	writer := f.writerForIndex(q)
-	if writer == nil {
-		f.l.WithField("udpAddr", addr).
-			WithField("writer", q).
-			Error("Failed to write outgoing packet: no writer available")
-		pkt.Release()
-		return
-	}
-	if err := writer.WriteTo(pkt.Payload()[:pkt.Len], addr); err != nil {
-		hostinfo.logger(f.l).
-			WithError(err).
-			WithField("udpAddr", addr).
-			Error("Failed to write outgoing packet")
-	}
-	pkt.Release()
-}
-
-func (f *Interface) writePacketToTun(q int, pkt *overlay.Packet) {
-	if pkt == nil {
-		return
-	}
-	writer := f.readers[q]
-	if writer == nil {
-		pkt.Release()
-		return
-	}
-	if bw, ok := writer.(interface {
-		WriteBatch([]*overlay.Packet) (int, error)
-	}); ok {
-		if _, err := bw.WriteBatch([]*overlay.Packet{pkt}); err != nil {
-			f.l.WithError(err).WithField("queue", q).Warn("Failed to write tun packet via batch writer")
-			pkt.Release()
-		}
-		return
-	}
-	if _, err := writer.Write(pkt.Payload()[:pkt.Len]); err != nil {
-		f.l.WithError(err).Error("Failed to write to tun")
-	}
-	pkt.Release()
-}
-
-func (f *Interface) clonePacketWithHeadroom(pkt *overlay.Packet, required int) *overlay.Packet {
-	if pkt == nil {
 		return nil
 	}
-	payload := pkt.Payload()[:pkt.Len]
+
-	if len(payload) == 0 && required <= 0 {
+	// Check if the reader/writer supports batch operations
-		return pkt
+	if batchWriter, ok := f.readers[q].(BatchWriter); ok {
+		_, err := batchWriter.BatchWrite(packets)
+		return err
 	}
 
-	pool := f.batches.Pool()
+	// Fall back to writing packets individually
-	if pool != nil {
+	for _, packet := range packets {
-		if clone := pool.Get(); clone != nil {
+		if _, err := f.readers[q].Write(packet); err != nil {
-			if len(clone.Payload()) >= len(payload) {
+			return err
-				clone.Len = copy(clone.Payload(), payload)
-				pkt.Release()
-				return clone
 		}
-			clone.Release()
 	}
+	return nil
 }
 
-	if required < 0 {
+// writeTun writes a single packet to the TUN device
-		required = 0
+func (f *Interface) writeTun(q int, packet []byte) error {
-	}
+	_, err := f.readers[q].Write(packet)
-	buf := make([]byte, required+len(payload))
+	return err
-	n := copy(buf[required:], payload)
-	pkt.Release()
-	return &overlay.Packet{
-		Buf:    buf,
-		Offset: required,
-		Len:    n,
-	}
-}
-
-func (f *Interface) observeUDPQueueLen(i int) {
-	if f.batchUDPQueueGauge == nil {
-		return
-	}
-	f.batchUDPQueueGauge.Update(int64(f.batches.txQueueLen(i)))
-}
-
-func (f *Interface) observeTunQueueLen(i int) {
-	if f.batchTunQueueGauge == nil {
-		return
-	}
-	f.batchTunQueueGauge.Update(int64(f.batches.tunQueueLen(i)))
-}
-
-func (f *Interface) currentBatchFlushInterval() time.Duration {
-	if v := f.batchFlushInterval.Load(); v > 0 {
-		return time.Duration(v)
-	}
-	return 0
-}
-
-func (f *Interface) ensurePacketHeadroom(pkt **overlay.Packet, required int, queue int, reason string) bool {
-	p := *pkt
-	if p == nil {
-		return false
-	}
-	if required <= 0 || p.Offset >= required {
-		return true
-	}
-	clone := f.clonePacketWithHeadroom(p, required)
-	if clone == nil {
-		f.l.WithFields(logrus.Fields{
-			"queue":  queue,
-			"reason": reason,
-		}).Warn("dropping packet lacking tun headroom")
-		return false
-	}
-	*pkt = clone
-	return true
-}
-
-func isVirtioHeadroomError(err error) bool {
-	if err == nil {
-		return false
-	}
-	msg := err.Error()
-	return strings.Contains(msg, "headroom") || strings.Contains(msg, "virtio")
-}
-
-func (f *Interface) effectiveGSOMaxSegments() int {
-	max := f.gsoMaxSegments
-	if max <= 0 {
-		max = defaultGSOMaxSegments
-	}
-	if max > maxKernelGSOSegments {
-		max = maxKernelGSOSegments
-	}
-	if !f.enableGSO {
-		return 1
-	}
-	return max
-}
-
-type udpOffloadConfigurator interface {
-	ConfigureOffload(enableGSO, enableGRO bool, maxSegments int)
-}
-
-func (f *Interface) applyOffloadConfig(enableGSO, enableGRO bool, maxSegments int) {
-	if maxSegments <= 0 {
-		maxSegments = defaultGSOMaxSegments
-	}
-	if maxSegments > maxKernelGSOSegments {
-		maxSegments = maxKernelGSOSegments
-	}
-	f.enableGSO = enableGSO
-	f.enableGRO = enableGRO
-	f.gsoMaxSegments = maxSegments
-	for _, writer := range f.writers {
-		if cfg, ok := writer.(udpOffloadConfigurator); ok {
-			cfg.ConfigureOffload(enableGSO, enableGRO, maxSegments)
-		}
-	}
 }
 
 func (f *Interface) RegisterConfigChangeCallbacks(c *config.C) {
@@ -1062,42 +497,6 @@ func (f *Interface) reloadMisc(c *config.C) {
 		f.reQueryWait.Store(int64(n))
 		f.l.Info("timers.requery_wait_duration has changed")
 	}
-
-	if c.HasChanged("listen.gso_flush_timeout") {
-		d := c.GetDuration("listen.gso_flush_timeout", defaultGSOFlushInterval)
-		if d < 0 {
-			d = 0
-		}
-		f.batchFlushInterval.Store(int64(d))
-		f.l.WithField("duration", d).Info("listen.gso_flush_timeout has changed")
-	} else if c.HasChanged("batch.flush_interval") {
-		d := c.GetDuration("batch.flush_interval", defaultGSOFlushInterval)
-		if d < 0 {
-			d = 0
-		}
-		f.batchFlushInterval.Store(int64(d))
-		f.l.WithField("duration", d).Warn("batch.flush_interval is deprecated; use listen.gso_flush_timeout")
-	}
-
-	if c.HasChanged("batch.queue_depth") {
-		n := c.GetInt("batch.queue_depth", f.batchQueueDepth)
-		if n != f.batchQueueDepth {
-			f.batchQueueDepth = n
-			f.l.Warn("batch.queue_depth changes require a restart to take effect")
-		}
-	}
-
-	if c.HasChanged("listen.enable_gso") || c.HasChanged("listen.enable_gro") || c.HasChanged("listen.gso_max_segments") {
-		enableGSO := c.GetBool("listen.enable_gso", f.enableGSO)
-		enableGRO := c.GetBool("listen.enable_gro", f.enableGRO)
-		maxSeg := c.GetInt("listen.gso_max_segments", f.gsoMaxSegments)
-		f.applyOffloadConfig(enableGSO, enableGRO, maxSeg)
-		f.l.WithFields(logrus.Fields{
-			"enableGSO":      enableGSO,
-			"enableGRO":      enableGRO,
-			"gsoMaxSegments": maxSeg,
-		}).Info("listen GSO/GRO configuration updated")
-	}
 }
 
 func (f *Interface) emitStats(ctx context.Context, i time.Duration) {

main.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
-	"runtime"
 	"time"
 
 	"github.com/sirupsen/logrus"
@@ -144,20 +143,6 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 	// set up our UDP listener
 	udpConns := make([]udp.Conn, routines)
 	port := c.GetInt("listen.port", 0)
-	enableGSO := c.GetBool("listen.enable_gso", true)
-	enableGRO := c.GetBool("listen.enable_gro", true)
-	gsoMaxSegments := c.GetInt("listen.gso_max_segments", defaultGSOMaxSegments)
-	if gsoMaxSegments <= 0 {
-		gsoMaxSegments = defaultGSOMaxSegments
-	}
-	if gsoMaxSegments > maxKernelGSOSegments {
-		gsoMaxSegments = maxKernelGSOSegments
-	}
-	gsoFlushTimeout := c.GetDuration("listen.gso_flush_timeout", defaultGSOFlushInterval)
-	if gsoFlushTimeout < 0 {
-		gsoFlushTimeout = 0
-	}
-	batchQueueDepth := c.GetInt("batch.queue_depth", 0)
 
 	if !configTest {
 		rawListenHost := c.GetString("listen.host", "0.0.0.0")
@@ -177,27 +162,13 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 			listenHost = ips[0].Unmap()
 		}
 
-		useWGDefault := runtime.GOOS == "linux"
-		useWG := c.GetBool("listen.use_wireguard_stack", useWGDefault)
-		var mkListener func(*logrus.Logger, netip.Addr, int, bool, int) (udp.Conn, error)
-		if useWG {
-			mkListener = udp.NewWireguardListener
-		} else {
-			mkListener = udp.NewListener
-		}
-
 		for i := 0; i < routines; i++ {
 			l.Infof("listening on %v", netip.AddrPortFrom(listenHost, uint16(port)))
-			udpServer, err := mkListener(l, listenHost, port, routines > 1, c.GetInt("listen.batch", 64))
+			udpServer, err := udp.NewListener(l, listenHost, port, routines > 1, c.GetInt("listen.batch", 64))
 			if err != nil {
 				return nil, util.NewContextualError("Failed to open udp listener", m{"queue": i}, err)
 			}
 			udpServer.ReloadConfig(c)
-			if cfg, ok := udpServer.(interface {
-				ConfigureOffload(bool, bool, int)
-			}); ok {
-				cfg.ConfigureOffload(enableGSO, enableGRO, gsoMaxSegments)
-			}
 			udpConns[i] = udpServer
 
 			// If port is dynamic, discover it before the next pass through the for loop
@@ -265,17 +236,13 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		reQueryWait:           c.GetDuration("timers.requery_wait_duration", defaultReQueryWait),
 		DropLocalBroadcast:    c.GetBool("tun.drop_local_broadcast", false),
 		DropMulticast:         c.GetBool("tun.drop_multicast", false),
-		EnableGSO:             enableGSO,
-		EnableGRO:             enableGRO,
-		GSOMaxSegments:        gsoMaxSegments,
 		routines:              routines,
 		MessageMetrics:        messageMetrics,
 		version:               buildVersion,
 		relayManager:          NewRelayManager(ctx, l, hostMap, c),
 		punchy:                punchy,
 		ConntrackCacheTimeout: conntrackCacheTimeout,
-		BatchFlushInterval:    gsoFlushTimeout,
+		batchSize:             c.GetInt("tun.batch_size", 64),
-		BatchQueueDepth:       batchQueueDepth,
 		l:                     l,
 	}
 
@@ -287,7 +254,6 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		}
 
 		ifce.writers = udpConns
-		ifce.applyOffloadConfig(enableGSO, enableGRO, gsoMaxSegments)
 		lightHouse.ifce = ifce
 
 		ifce.RegisterConfigChangeCallbacks(c)

outside.go

@@ -12,7 +12,6 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/firewall"
 	"github.com/slackhq/nebula/header"
-	"github.com/slackhq/nebula/overlay"
 	"golang.org/x/net/ipv4"
 )
 
@@ -20,7 +19,7 @@ const (
 	minFwPacketLen = 4
 )
 
-func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []byte, packet []byte, h *header.H, fwPacket *firewall.Packet, lhf *LightHouseHandler, nb []byte, q int, localCache *firewall.ConntrackCache) {
+func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []byte, packet []byte, h *header.H, fwPacket *firewall.Packet, lhf *LightHouseHandler, nb []byte, q int, localCache firewall.ConntrackCache) {
 	err := h.Parse(packet)
 	if err != nil {
 		// Hole punch packets are 0 or 1 byte big, so lets ignore printing those errors
@@ -62,7 +61,7 @@ func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []
 
 		switch h.Subtype {
 		case header.MessageNone:
-			if !f.decryptToTun(hostinfo, h.MessageCounter, out, packet, fwPacket, nb, q, localCache, ip, h.RemoteIndex) {
+			if !f.decryptToTun(hostinfo, h.MessageCounter, out, packet, fwPacket, nb, q, localCache) {
 				return
 			}
 		case header.MessageRelay:
@@ -334,12 +333,13 @@ func parseV6(data []byte, incoming bool, fp *firewall.Packet) error {
 			}
 
 			fp.Protocol = uint8(proto)
+			ports := data[offset : offset+4]
 			if incoming {
-				fp.RemotePort = binary.BigEndian.Uint16(data[offset : offset+2])
+				fp.RemotePort = binary.BigEndian.Uint16(ports[0:2])
-				fp.LocalPort = binary.BigEndian.Uint16(data[offset+2 : offset+4])
+				fp.LocalPort = binary.BigEndian.Uint16(ports[2:4])
 			} else {
-				fp.LocalPort = binary.BigEndian.Uint16(data[offset : offset+2])
+				fp.LocalPort = binary.BigEndian.Uint16(ports[0:2])
-				fp.RemotePort = binary.BigEndian.Uint16(data[offset+2 : offset+4])
+				fp.RemotePort = binary.BigEndian.Uint16(ports[2:4])
 			}
 
 			fp.Fragment = false
@@ -466,45 +466,23 @@ func (f *Interface) decrypt(hostinfo *HostInfo, mc uint64, out []byte, packet []
 	return out, nil
 }
 
-func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out []byte, packet []byte, fwPacket *firewall.Packet, nb []byte, q int, localCache *firewall.ConntrackCache, addr netip.AddrPort, recvIndex uint32) bool {
+func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out []byte, packet []byte, fwPacket *firewall.Packet, nb []byte, q int, localCache firewall.ConntrackCache) bool {
-	var (
+	var err error
-		err error
-		pkt *overlay.Packet
-	)
-
-	if f.batches.tunQueue(q) != nil {
-		pkt = f.batches.newPacket()
-		if pkt != nil {
-			out = pkt.Payload()[:0]
-		}
-	}
 
 	out, err = hostinfo.ConnectionState.dKey.DecryptDanger(out, packet[:header.Len], packet[header.Len:], messageCounter, nb)
 	if err != nil {
-		if pkt != nil {
-			pkt.Release()
-		}
 		hostinfo.logger(f.l).WithError(err).Error("Failed to decrypt packet")
-		if addr.IsValid() {
-			f.maybeSendRecvError(addr, recvIndex)
-		}
 		return false
 	}
 
 	err = newPacket(out, true, fwPacket)
 	if err != nil {
-		if pkt != nil {
-			pkt.Release()
-		}
 		hostinfo.logger(f.l).WithError(err).WithField("packet", out).
 			Warnf("Error while validating inbound packet")
 		return false
 	}
 
 	if !hostinfo.ConnectionState.window.Update(f.l, messageCounter) {
-		if pkt != nil {
-			pkt.Release()
-		}
 		hostinfo.logger(f.l).WithField("fwPacket", fwPacket).
 			Debugln("dropping out of window packet")
 		return false
@@ -512,9 +490,6 @@ func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out
 
 	dropReason := f.firewall.Drop(*fwPacket, true, hostinfo, f.pki.GetCAPool(), localCache)
 	if dropReason != nil {
-		if pkt != nil {
-			pkt.Release()
-		}
 		// NOTE: We give `packet` as the `out` here since we already decrypted from it and we don't need it anymore
 		// This gives us a buffer to build the reject packet in
 		f.rejectOutside(out, hostinfo.ConnectionState, hostinfo, nb, packet, q)
@@ -527,17 +502,8 @@ func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out
 	}
 
 	f.connectionManager.In(hostinfo)
-	if pkt != nil {
+	_, err = f.readers[q].Write(out)
-		pkt.Len = len(out)
+	if err != nil {
-		if f.batches.enqueueTun(q, pkt) {
-			f.observeTunQueueLen(q)
-			return true
-		}
-		f.writePacketToTun(q, pkt)
-		return true
-	}
-
-	if _, err = f.readers[q].Write(out); err != nil {
 		f.l.WithError(err).Error("Failed to write to tun")
 	}
 	return true

overlay/device.go

@@ -3,7 +3,6 @@ package overlay
 import (
 	"io"
 	"net/netip"
-	"sync"
 
 	"github.com/slackhq/nebula/routing"
 )
@@ -16,84 +15,3 @@ type Device interface {
 	RoutesFor(netip.Addr) routing.Gateways
 	NewMultiQueueReader() (io.ReadWriteCloser, error)
 }
-
-// Packet represents a single packet buffer with optional headroom to carry
-// metadata (for example virtio-net headers).
-type Packet struct {
-	Buf     []byte
-	Offset  int
-	Len     int
-	release func()
-}
-
-func (p *Packet) Payload() []byte {
-	return p.Buf[p.Offset : p.Offset+p.Len]
-}
-
-func (p *Packet) Reset() {
-	p.Len = 0
-	p.Offset = 0
-	p.release = nil
-}
-
-func (p *Packet) Release() {
-	if p.release != nil {
-		p.release()
-		p.release = nil
-	}
-}
-
-func (p *Packet) Capacity() int {
-	return len(p.Buf) - p.Offset
-}
-
-// PacketPool manages reusable buffers with headroom.
-type PacketPool struct {
-	headroom int
-	blksz    int
-	pool     sync.Pool
-}
-
-func NewPacketPool(headroom, payload int) *PacketPool {
-	p := &PacketPool{headroom: headroom, blksz: headroom + payload}
-	p.pool.New = func() any {
-		buf := make([]byte, p.blksz)
-		return &Packet{Buf: buf, Offset: headroom}
-	}
-	return p
-}
-
-func (p *PacketPool) Get() *Packet {
-	pkt := p.pool.Get().(*Packet)
-	pkt.Offset = p.headroom
-	pkt.Len = 0
-	pkt.release = func() { p.put(pkt) }
-	return pkt
-}
-
-func (p *PacketPool) put(pkt *Packet) {
-	pkt.Reset()
-	p.pool.Put(pkt)
-}
-
-// BatchReader allows reading multiple packets into a shared pool with
-// preallocated headroom (e.g. virtio-net headers).
-type BatchReader interface {
-	ReadIntoBatch(pool *PacketPool) ([]*Packet, error)
-}
-
-// BatchWriter writes a slice of packets that carry their own metadata.
-type BatchWriter interface {
-	WriteBatch(packets []*Packet) (int, error)
-}
-
-// BatchCapableDevice describes a device that can efficiently read and write
-// batches of packets with virtio headroom.
-type BatchCapableDevice interface {
-	Device
-	BatchReader
-	BatchWriter
-	BatchHeadroom() int
-	BatchPayloadCap() int
-	BatchSize() int
-}

overlay/route.go

@@ -3,7 +3,6 @@ package overlay
 import (
 	"fmt"
 	"math"
-	"net"
 	"net/netip"
 	"runtime"
 	"strconv"
@@ -305,29 +304,3 @@ func parseUnsafeRoutes(c *config.C, networks []netip.Prefix) ([]Route, error) {
 
 	return routes, nil
 }
-
-func ipWithin(o *net.IPNet, i *net.IPNet) bool {
-	// Make sure o contains the lowest form of i
-	if !o.Contains(i.IP.Mask(i.Mask)) {
-		return false
-	}
-
-	// Find the max ip in i
-	ip4 := i.IP.To4()
-	if ip4 == nil {
-		return false
-	}
-
-	last := make(net.IP, len(ip4))
-	copy(last, ip4)
-	for x := range ip4 {
-		last[x] |= ^i.Mask[x]
-	}
-
-	// Make sure o contains the max
-	if !o.Contains(last) {
-		return false
-	}
-
-	return true
-}

overlay/route_test.go

@@ -225,6 +225,7 @@ func Test_parseUnsafeRoutes(t *testing.T) {
 	// no mtu
 	c.Settings["tun"] = map[string]any{"unsafe_routes": []any{map[string]any{"via": "127.0.0.1", "route": "1.0.0.0/8"}}}
 	routes, err = parseUnsafeRoutes(c, []netip.Prefix{n})
+	require.NoError(t, err)
 	assert.Len(t, routes, 1)
 	assert.Equal(t, 0, routes[0].MTU)
 
@@ -318,7 +319,7 @@ func Test_makeRouteTree(t *testing.T) {
 
 	ip, err = netip.ParseAddr("1.1.0.1")
 	require.NoError(t, err)
-	r, ok = routeTree.Lookup(ip)
+	_, ok = routeTree.Lookup(ip)
 	assert.False(t, ok)
 }
 

overlay/tun.go

@@ -1,8 +1,6 @@
 package overlay
 
 import (
-	"fmt"
-	"net"
 	"net/netip"
 
 	"github.com/sirupsen/logrus"
@@ -72,51 +70,3 @@ func findRemovedRoutes(newRoutes, oldRoutes []Route) []Route {
 
 	return removed
 }
-
-func prefixToMask(prefix netip.Prefix) netip.Addr {
-	pLen := 128
-	if prefix.Addr().Is4() {
-		pLen = 32
-	}
-
-	addr, _ := netip.AddrFromSlice(net.CIDRMask(prefix.Bits(), pLen))
-	return addr
-}
-
-func flipBytes(b []byte) []byte {
-	for i := 0; i < len(b); i++ {
-		b[i] ^= 0xFF
-	}
-	return b
-}
-func orBytes(a []byte, b []byte) []byte {
-	ret := make([]byte, len(a))
-	for i := 0; i < len(a); i++ {
-		ret[i] = a[i] | b[i]
-	}
-	return ret
-}
-
-func getBroadcast(cidr netip.Prefix) netip.Addr {
-	broadcast, _ := netip.AddrFromSlice(
-		orBytes(
-			cidr.Addr().AsSlice(),
-			flipBytes(prefixToMask(cidr).AsSlice()),
-		),
-	)
-	return broadcast
-}
-
-func selectGateway(dest netip.Prefix, gateways []netip.Prefix) (netip.Prefix, error) {
-	for _, gateway := range gateways {
-		if dest.Addr().Is4() && gateway.Addr().Is4() {
-			return gateway, nil
-		}
-
-		if dest.Addr().Is6() && gateway.Addr().Is6() {
-			return gateway, nil
-		}
-	}
-
-	return netip.Prefix{}, fmt.Errorf("no gateway found for %v in the list of vpn networks", dest)
-}

overlay/tun_darwin.go

@@ -1,5 +1,5 @@
-//go:build !ios && !e2e_testing
+//go:build darwin && !ios && !e2e_testing
-// +build !ios,!e2e_testing
+// +build darwin,!ios,!e2e_testing
 
 package overlay
 
@@ -8,48 +8,27 @@ import (
 	"fmt"
 	"io"
 	"net/netip"
-	"os"
-	"sync/atomic"
-	"syscall"
 	"unsafe"
 
-	"github.com/gaissmai/bart"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/routing"
 	"github.com/slackhq/nebula/util"
 	netroute "golang.org/x/net/route"
 	"golang.org/x/sys/unix"
+	wgtun "golang.zx2c4.com/wireguard/tun"
 )
 
 type tun struct {
-	io.ReadWriteCloser
-	Device      string
-	vpnNetworks []netip.Prefix
-	DefaultMTU  int
-	Routes      atomic.Pointer[[]Route]
-	routeTree   atomic.Pointer[bart.Table[routing.Gateways]]
 	linkAddr *netroute.LinkAddr
-	l           *logrus.Logger
-
-	// cache out buffer since we need to prepend 4 bytes for tun metadata
-	out []byte
 }
 
+// ioctl structures for Darwin network configuration
 type ifReq struct {
 	Name  [unix.IFNAMSIZ]byte
 	Flags uint16
 	pad   [8]byte
 }
 
-const (
-	_SIOCAIFADDR_IN6 = 2155899162
-	_UTUN_OPT_IFNAME = 2
-	_IN6_IFF_NODAD   = 0x0020
-	_IN6_IFF_SECURED = 0x0400
-	utunControlName  = "com.apple.net.utun_control"
-)
-
 type ifreqMTU struct {
 	Name [16]byte
 	MTU  int32
@@ -79,60 +58,61 @@ type ifreqAlias6 struct {
 	Lifetime   addrLifetime
 }
 
-func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*tun, error) {
+const (
+	_SIOCAIFADDR_IN6 = 2155899162
+	_IN6_IFF_NODAD   = 0x0020
+)
+
+func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (*wgTun, error) {
+	return nil, fmt.Errorf("newTunFromFd not supported on Darwin")
+}
+
+func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*wgTun, error) {
 	name := c.GetString("tun.dev", "")
-	ifIndex := -1
+	deviceName := "utun"
+
+	// Parse device name to handle utun[0-9]+ format
 	if name != "" && name != "utun" {
+		ifIndex := -1
 		_, err := fmt.Sscanf(name, "utun%d", &ifIndex)
 		if err != nil || ifIndex < 0 {
 			// NOTE: we don't make this error so we don't break existing
 			// configs that set a name before it was used.
 			l.Warn("interface name must be utun[0-9]+ on Darwin, ignoring")
-			ifIndex = -1
+		} else {
+			deviceName = name
 		}
 	}
 
-	fd, err := unix.Socket(unix.AF_SYSTEM, unix.SOCK_DGRAM, unix.AF_SYS_CONTROL)
+	mtu := c.GetInt("tun.mtu", DefaultMTU)
+
+	// Create WireGuard TUN device
+	tunDevice, err := wgtun.CreateTUN(deviceName, mtu)
 	if err != nil {
-		return nil, fmt.Errorf("system socket: %v", err)
+		return nil, fmt.Errorf("failed to create TUN device: %w", err)
 	}
 
-	var ctlInfo = &unix.CtlInfo{}
+	// Get the actual device name
-	copy(ctlInfo.Name[:], utunControlName)
+	actualName, err := tunDevice.Name()
-
-	err = unix.IoctlCtlInfo(fd, ctlInfo)
 	if err != nil {
-		return nil, fmt.Errorf("CTLIOCGINFO: %v", err)
+		tunDevice.Close()
+		return nil, fmt.Errorf("failed to get TUN device name: %w", err)
 	}
 
-	err = unix.Connect(fd, &unix.SockaddrCtl{
+	t := &wgTun{
-		ID:   ctlInfo.Id,
+		tunDevice:   tunDevice,
-		Unit: uint32(ifIndex) + 1,
-	})
-	if err != nil {
-		return nil, fmt.Errorf("SYS_CONNECT: %v", err)
-	}
-
-	name, err = unix.GetsockoptString(fd, unix.AF_SYS_CONTROL, _UTUN_OPT_IFNAME)
-	if err != nil {
-		return nil, fmt.Errorf("failed to retrieve tun name: %w", err)
-	}
-
-	err = unix.SetNonblock(fd, true)
-	if err != nil {
-		return nil, fmt.Errorf("SetNonblock: %v", err)
-	}
-
-	t := &tun{
-		ReadWriteCloser: os.NewFile(uintptr(fd), ""),
-		Device:          name,
 		vpnNetworks: vpnNetworks,
-		DefaultMTU:      c.GetInt("tun.mtu", DefaultMTU),
+		MaxMTU:      mtu,
+		DefaultMTU:  mtu,
 		l:           l,
 	}
 
+	// Create Darwin-specific route manager
+	t.routeManager = &tun{}
+
 	err = t.reload(c, true)
 	if err != nil {
+		tunDevice.Close()
 		return nil, err
 	}
 
@@ -143,215 +123,251 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (
 		}
 	})
 
+	l.WithField("name", actualName).Info("Created WireGuard TUN device")
+
 	return t, nil
 }
 
-func (t *tun) deviceBytes() (o [16]byte) {
+func (rm *tun) Activate(t *wgTun) error {
-	for i, c := range t.Device {
+	name, err := t.tunDevice.Name()
-		o[i] = byte(c)
-	}
-	return
-}
-
-func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (*tun, error) {
-	return nil, fmt.Errorf("newTunFromFd not supported in Darwin")
-}
-
-func (t *tun) Close() error {
-	if t.ReadWriteCloser != nil {
-		return t.ReadWriteCloser.Close()
-	}
-	return nil
-}
-
-func (t *tun) Activate() error {
-	devName := t.deviceBytes()
-
-	s, err := unix.Socket(
-		unix.AF_INET,
-		unix.SOCK_DGRAM,
-		unix.IPPROTO_IP,
-	)
 	if err != nil {
+		return fmt.Errorf("failed to get device name: %w", err)
+	}
+
+	// Set the MTU
+	rm.SetMTU(t, t.MaxMTU)
+
+	// Add IP addresses
+	for _, network := range t.vpnNetworks {
+		if err := rm.addIP(t, name, network); err != nil {
 			return err
 		}
-	defer unix.Close(s)
-
-	fd := uintptr(s)
-
-	// Set the MTU on the device
-	ifm := ifreqMTU{Name: devName, MTU: int32(t.DefaultMTU)}
-	if err = ioctl(fd, unix.SIOCSIFMTU, uintptr(unsafe.Pointer(&ifm))); err != nil {
-		return fmt.Errorf("failed to set tun mtu: %v", err)
 	}
 
-	// Get the device flags
+	// Bring up the interface using ioctl
-	ifrf := ifReq{Name: devName}
+	if err := rm.bringUpInterface(name); err != nil {
-	if err = ioctl(fd, unix.SIOCGIFFLAGS, uintptr(unsafe.Pointer(&ifrf))); err != nil {
+		return fmt.Errorf("failed to bring up interface: %w", err)
-		return fmt.Errorf("failed to get tun flags: %s", err)
 	}
 
-	linkAddr, err := getLinkAddr(t.Device)
+	// Get the link address for routing
+	linkAddr, err := getLinkAddr(name)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to get link address: %w", err)
 	}
 	if linkAddr == nil {
 		return fmt.Errorf("unable to discover link_addr for tun interface")
 	}
-	t.linkAddr = linkAddr
+	rm.linkAddr = linkAddr
 
-	for _, network := range t.vpnNetworks {
+	// Set the routes
-		if network.Addr().Is4() {
+	if err := rm.AddRoutes(t, false); err != nil {
-			err = t.activate4(network)
-			if err != nil {
 		return err
 	}
+
+	return nil
+}
+
+func (rm *tun) bringUpInterface(name string) error {
+	// Open a socket for ioctl
+	fd, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, 0)
+	if err != nil {
+		return fmt.Errorf("failed to create socket: %w", err)
+	}
+	defer unix.Close(fd)
+
+	// Get current flags
+	var ifrf ifReq
+	copy(ifrf.Name[:], name)
+
+	if err := ioctl(uintptr(fd), unix.SIOCGIFFLAGS, uintptr(unsafe.Pointer(&ifrf))); err != nil {
+		return fmt.Errorf("failed to get interface flags: %w", err)
+	}
+
+	// Set IFF_UP and IFF_RUNNING flags
+	ifrf.Flags = ifrf.Flags | unix.IFF_UP | unix.IFF_RUNNING
+
+	if err := ioctl(uintptr(fd), unix.SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifrf))); err != nil {
+		return fmt.Errorf("failed to set interface flags: %w", err)
+	}
+
+	return nil
+}
+
+func (rm *tun) SetMTU(t *wgTun, mtu int) {
+	name, err := t.tunDevice.Name()
+	if err != nil {
+		t.l.WithError(err).Error("Failed to get device name for MTU set")
+		return
+	}
+
+	// Open a socket for ioctl
+	fd, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, 0)
+	if err != nil {
+		t.l.WithError(err).Error("Failed to create socket for MTU set")
+		return
+	}
+	defer unix.Close(fd)
+
+	// Prepare the ioctl request
+	var ifr ifreqMTU
+	copy(ifr.Name[:], name)
+	ifr.MTU = int32(mtu)
+
+	// Set the MTU using ioctl
+	if err := ioctl(uintptr(fd), unix.SIOCSIFMTU, uintptr(unsafe.Pointer(&ifr))); err != nil {
+		t.l.WithError(err).Error("Failed to set tun mtu via ioctl")
+	}
+}
+
+func (rm *tun) SetDefaultRoute(t *wgTun, cidr netip.Prefix) error {
+	// On Darwin, routes are set via ifconfig and route commands
+	return nil
+}
+
+func (rm *tun) AddRoutes(t *wgTun, logErrors bool) error {
+	routes := *t.Routes.Load()
+	for _, r := range routes {
+		if !r.Install {
+			continue
+		}
+
+		err := rm.addRoute(r.Cidr)
+		if err != nil {
+			if errors.Is(err, unix.EEXIST) {
+				t.l.WithField("route", r.Cidr).
+					Warnf("unable to add unsafe_route, identical route already exists")
+			} else {
+				retErr := util.NewContextualError("Failed to add route", map[string]any{"route": r}, err)
+				if logErrors {
+					retErr.Log(t.l)
+				} else {
+					return retErr
+				}
+			}
 		} else {
-			err = t.activate6(network)
+			t.l.WithField("route", r).Info("Added route")
+		}
+	}
+
+	return nil
+}
+
+func (rm *tun) RemoveRoutes(t *wgTun, routes []Route) {
+	for _, r := range routes {
+		if !r.Install {
+			continue
+		}
+
+		err := rm.delRoute(r.Cidr)
 		if err != nil {
-				return err
+			t.l.WithError(err).WithField("route", r).Error("Failed to remove route")
+		} else {
+			t.l.WithField("route", r).Info("Removed route")
 		}
 	}
 }
 
-	// Run the interface
+func (rm *tun) NewMultiQueueReader(t *wgTun) (io.ReadWriteCloser, error) {
-	ifrf.Flags = ifrf.Flags | unix.IFF_UP | unix.IFF_RUNNING
+	// Darwin doesn't support multi-queue TUN devices in the same way as Linux
-	if err = ioctl(fd, unix.SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifrf))); err != nil {
+	// Return a reader that wraps the same device
-		return fmt.Errorf("failed to run tun device: %s", err)
+	return &wgTunReader{
+		parent:    t,
+		tunDevice: t.tunDevice,
+		offset:    0,
+		l:         t.l,
+	}, nil
 }
 
-	// Unsafe path routes
+func (rm *tun) addIP(t *wgTun, name string, network netip.Prefix) error {
-	return t.addRoutes(false)
+	addr := network.Addr()
+
+	if addr.Is4() {
+		return rm.addIPv4(name, network)
+	} else {
+		return rm.addIPv6(name, network)
+	}
 }
 
-func (t *tun) activate4(network netip.Prefix) error {
+func (rm *tun) addIPv4(name string, network netip.Prefix) error {
-	s, err := unix.Socket(
+	// Open an IPv4 socket for ioctl
-		unix.AF_INET,
+	s, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
-		unix.SOCK_DGRAM,
-		unix.IPPROTO_IP,
-	)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to create IPv4 socket: %w", err)
 	}
 	defer unix.Close(s)
 
-	ifr := ifreqAlias4{
+	var ifr ifreqAlias4
-		Name: t.deviceBytes(),
+	copy(ifr.Name[:], name)
-		Addr: unix.RawSockaddrInet4{
+
+	// Set the address
+	ifr.Addr = unix.RawSockaddrInet4{
 		Len:    unix.SizeofSockaddrInet4,
 		Family: unix.AF_INET,
 		Addr:   network.Addr().As4(),
-		},
+	}
-		DstAddr: unix.RawSockaddrInet4{
+
+	// Set the destination address (same as address for point-to-point)
+	ifr.DstAddr = unix.RawSockaddrInet4{
 		Len:    unix.SizeofSockaddrInet4,
 		Family: unix.AF_INET,
 		Addr:   network.Addr().As4(),
-		},
+	}
-		MaskAddr: unix.RawSockaddrInet4{
+
+	// Set the netmask
+	ifr.MaskAddr = unix.RawSockaddrInet4{
 		Len:    unix.SizeofSockaddrInet4,
 		Family: unix.AF_INET,
 		Addr:   prefixToMask(network).As4(),
-		},
 	}
 
 	if err := ioctl(uintptr(s), unix.SIOCAIFADDR, uintptr(unsafe.Pointer(&ifr))); err != nil {
-		return fmt.Errorf("failed to set tun v4 address: %s", err)
+		return fmt.Errorf("failed to set IPv4 address via ioctl: %w", err)
-	}
-
-	err = addRoute(network, t.linkAddr)
-	if err != nil {
-		return err
 	}
 
 	return nil
 }
 
-func (t *tun) activate6(network netip.Prefix) error {
+func (rm *tun) addIPv6(name string, network netip.Prefix) error {
-	s, err := unix.Socket(
+	// Open an IPv6 socket for ioctl
-		unix.AF_INET6,
+	s, err := unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, unix.IPPROTO_IP)
-		unix.SOCK_DGRAM,
-		unix.IPPROTO_IP,
-	)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to create IPv6 socket: %w", err)
 	}
 	defer unix.Close(s)
 
-	ifr := ifreqAlias6{
+	var ifr ifreqAlias6
-		Name: t.deviceBytes(),
+	copy(ifr.Name[:], name)
-		Addr: unix.RawSockaddrInet6{
+
+	// Set the address
+	ifr.Addr = unix.RawSockaddrInet6{
 		Len:    unix.SizeofSockaddrInet6,
 		Family: unix.AF_INET6,
 		Addr:   network.Addr().As16(),
-		},
+	}
-		PrefixMask: unix.RawSockaddrInet6{
+
+	// Set the prefix mask
+	ifr.PrefixMask = unix.RawSockaddrInet6{
 		Len:    unix.SizeofSockaddrInet6,
 		Family: unix.AF_INET6,
 		Addr:   prefixToMask(network).As16(),
-		},
+	}
-		Lifetime: addrLifetime{
+
-			// never expires
+	// Set lifetime (never expires)
+	ifr.Lifetime = addrLifetime{
 		Vltime: 0xffffffff,
 		Pltime: 0xffffffff,
-		},
-		Flags: _IN6_IFF_NODAD,
 	}
 
+	// Set flags (no DAD - Duplicate Address Detection)
+	ifr.Flags = _IN6_IFF_NODAD
+
 	if err := ioctl(uintptr(s), _SIOCAIFADDR_IN6, uintptr(unsafe.Pointer(&ifr))); err != nil {
-		return fmt.Errorf("failed to set tun address: %s", err)
+		return fmt.Errorf("failed to set IPv6 address via ioctl: %w", err)
 	}
 
 	return nil
 }
 
-func (t *tun) reload(c *config.C, initial bool) error {
-	change, routes, err := getAllRoutesFromConfig(c, t.vpnNetworks, initial)
-	if err != nil {
-		return err
-	}
-
-	if !initial && !change {
-		return nil
-	}
-
-	routeTree, err := makeRouteTree(t.l, routes, false)
-	if err != nil {
-		return err
-	}
-
-	// Teach nebula how to handle the routes before establishing them in the system table
-	oldRoutes := t.Routes.Swap(&routes)
-	t.routeTree.Store(routeTree)
-
-	if !initial {
-		// Remove first, if the system removes a wanted route hopefully it will be re-added next
-		err := t.removeRoutes(findRemovedRoutes(routes, *oldRoutes))
-		if err != nil {
-			util.LogWithContextIfNeeded("Failed to remove routes", err, t.l)
-		}
-
-		// Ensure any routes we actually want are installed
-		err = t.addRoutes(true)
-		if err != nil {
-			// Catch any stray logs
-			util.LogWithContextIfNeeded("Failed to add routes", err, t.l)
-		}
-	}
-
-	return nil
-}
-
-func (t *tun) RoutesFor(ip netip.Addr) routing.Gateways {
-	r, ok := t.routeTree.Load().Lookup(ip)
-	if ok {
-		return r
-	}
-	return routing.Gateways{}
-}
-
-// Get the LinkAddr for the interface of the given name
-// Is there an easier way to fetch this when we create the interface?
-// Maybe SIOCGIFINDEX? but this doesn't appear to exist in the darwin headers.
 func getLinkAddr(name string) (*netroute.LinkAddr, error) {
 	rib, err := netroute.FetchRIB(unix.AF_UNSPEC, unix.NET_RT_IFLIST, 0)
 	if err != nil {
@@ -377,53 +393,7 @@ func getLinkAddr(name string) (*netroute.LinkAddr, error) {
 	return nil, nil
 }
 
-func (t *tun) addRoutes(logErrors bool) error {
+func (rm *tun) addRoute(prefix netip.Prefix) error {
-	routes := *t.Routes.Load()
-
-	for _, r := range routes {
-		if len(r.Via) == 0 || !r.Install {
-			// We don't allow route MTUs so only install routes with a via
-			continue
-		}
-
-		err := addRoute(r.Cidr, t.linkAddr)
-		if err != nil {
-			if errors.Is(err, unix.EEXIST) {
-				t.l.WithField("route", r.Cidr).
-					Warnf("unable to add unsafe_route, identical route already exists")
-			} else {
-				retErr := util.NewContextualError("Failed to add route", map[string]any{"route": r}, err)
-				if logErrors {
-					retErr.Log(t.l)
-				} else {
-					return retErr
-				}
-			}
-		} else {
-			t.l.WithField("route", r).Info("Added route")
-		}
-	}
-
-	return nil
-}
-
-func (t *tun) removeRoutes(routes []Route) error {
-	for _, r := range routes {
-		if !r.Install {
-			continue
-		}
-
-		err := delRoute(r.Cidr, t.linkAddr)
-		if err != nil {
-			t.l.WithError(err).WithField("route", r).Error("Failed to remove route")
-		} else {
-			t.l.WithField("route", r).Info("Removed route")
-		}
-	}
-	return nil
-}
-
-func addRoute(prefix netip.Prefix, gateway netroute.Addr) error {
 	sock, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
 	if err != nil {
 		return fmt.Errorf("unable to create AF_ROUTE socket: %v", err)
@@ -441,13 +411,13 @@ func addRoute(prefix netip.Prefix, gateway netroute.Addr) error {
 		route.Addrs = []netroute.Addr{
 			unix.RTAX_DST:     &netroute.Inet4Addr{IP: prefix.Masked().Addr().As4()},
 			unix.RTAX_NETMASK: &netroute.Inet4Addr{IP: prefixToMask(prefix).As4()},
-			unix.RTAX_GATEWAY: gateway,
+			unix.RTAX_GATEWAY: rm.linkAddr,
 		}
 	} else {
 		route.Addrs = []netroute.Addr{
 			unix.RTAX_DST:     &netroute.Inet6Addr{IP: prefix.Masked().Addr().As16()},
 			unix.RTAX_NETMASK: &netroute.Inet6Addr{IP: prefixToMask(prefix).As16()},
-			unix.RTAX_GATEWAY: gateway,
+			unix.RTAX_GATEWAY: rm.linkAddr,
 		}
 	}
 
@@ -464,7 +434,7 @@ func addRoute(prefix netip.Prefix, gateway netroute.Addr) error {
 	return nil
 }
 
-func delRoute(prefix netip.Prefix, gateway netroute.Addr) error {
+func (rm *tun) delRoute(prefix netip.Prefix) error {
 	sock, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
 	if err != nil {
 		return fmt.Errorf("unable to create AF_ROUTE socket: %v", err)
@@ -481,13 +451,13 @@ func delRoute(prefix netip.Prefix, gateway netroute.Addr) error {
 		route.Addrs = []netroute.Addr{
 			unix.RTAX_DST:     &netroute.Inet4Addr{IP: prefix.Masked().Addr().As4()},
 			unix.RTAX_NETMASK: &netroute.Inet4Addr{IP: prefixToMask(prefix).As4()},
-			unix.RTAX_GATEWAY: gateway,
+			unix.RTAX_GATEWAY: rm.linkAddr,
 		}
 	} else {
 		route.Addrs = []netroute.Addr{
 			unix.RTAX_DST:     &netroute.Inet6Addr{IP: prefix.Masked().Addr().As16()},
 			unix.RTAX_NETMASK: &netroute.Inet6Addr{IP: prefixToMask(prefix).As16()},
-			unix.RTAX_GATEWAY: gateway,
+			unix.RTAX_GATEWAY: rm.linkAddr,
 		}
 	}
 
@@ -495,6 +465,7 @@ func delRoute(prefix netip.Prefix, gateway netroute.Addr) error {
 	if err != nil {
 		return fmt.Errorf("failed to create route.RouteMessage: %w", err)
 	}
+
 	_, err = unix.Write(sock, data[:])
 	if err != nil {
 		return fmt.Errorf("failed to write route.RouteMessage to socket: %w", err)
@@ -503,52 +474,34 @@ func delRoute(prefix netip.Prefix, gateway netroute.Addr) error {
 	return nil
 }
 
-func (t *tun) Read(to []byte) (int, error) {
+func ioctl(a1, a2, a3 uintptr) error {
-	buf := make([]byte, len(to)+4)
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, a1, a2, a3)
-
+	if errno != 0 {
-	n, err := t.ReadWriteCloser.Read(buf)
+		return errno
-
+	}
-	copy(to, buf[4:])
+	return nil
-	return n - 4, err
 }
 
-// Write is only valid for single threaded use
+func prefixToMask(prefix netip.Prefix) netip.Addr {
-func (t *tun) Write(from []byte) (int, error) {
+	bits := prefix.Bits()
-	buf := t.out
+	if prefix.Addr().Is4() {
-	if cap(buf) < len(from)+4 {
+		// Create IPv4 netmask from prefix length
-		buf = make([]byte, len(from)+4)
+		mask := ^uint32(0) << (32 - bits)
-		t.out = buf
+		return netip.AddrFrom4([4]byte{
-	}
+			byte(mask >> 24),
-	buf = buf[:len(from)+4]
+			byte(mask >> 16),
-
+			byte(mask >> 8),
-	if len(from) == 0 {
+			byte(mask),
-		return 0, syscall.EIO
+		})
-	}
-
-	// Determine the IP Family for the NULL L2 Header
-	ipVer := from[0] >> 4
-	if ipVer == 4 {
-		buf[3] = syscall.AF_INET
-	} else if ipVer == 6 {
-		buf[3] = syscall.AF_INET6
 	} else {
-		return 0, fmt.Errorf("unable to determine IP version from packet")
+		// Create IPv6 netmask from prefix length
+		var mask [16]byte
+		for i := 0; i < bits/8; i++ {
+			mask[i] = 0xff
 		}
-
+		if bits%8 != 0 {
-	copy(buf[4:], from)
+			mask[bits/8] = ^byte(0) << (8 - bits%8)
-
-	n, err := t.ReadWriteCloser.Write(buf)
-	return n - 4, err
 		}
-
+		return netip.AddrFrom16(mask)
-func (t *tun) Networks() []netip.Prefix {
-	return t.vpnNetworks
 	}
-
-func (t *tun) Name() string {
-	return t.Device
-}
-
-func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
-	return nil, fmt.Errorf("TODO: multiqueue not implemented for darwin")
 }

overlay/tun_freebsd.go

@@ -1,284 +1,77 @@
-//go:build !e2e_testing
+//go:build freebsd && !e2e_testing
-// +build !e2e_testing
+// +build freebsd,!e2e_testing
 
 package overlay
 
 import (
-	"bytes"
-	"errors"
 	"fmt"
 	"io"
-	"io/fs"
 	"net/netip"
-	"sync/atomic"
+	"os/exec"
+	"strconv"
+	"strings"
 	"syscall"
-	"time"
 	"unsafe"
 
-	"github.com/gaissmai/bart"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/routing"
 	"github.com/slackhq/nebula/util"
-	netroute "golang.org/x/net/route"
 	"golang.org/x/sys/unix"
+	wgtun "golang.zx2c4.com/wireguard/tun"
 )
 
-const (
+type tun struct{}
-	// FIODGNAME is defined in sys/sys/filio.h on FreeBSD
-	// For 32-bit systems, use FIODGNAME_32 (not defined in this file: 0x80086678)
-	FIODGNAME        = 0x80106678
-	TUNSIFMODE       = 0x8004745e
-	TUNSIFHEAD       = 0x80047460
-	OSIOCAIFADDR_IN6 = 0x8088691b
-	IN6_IFF_NODAD    = 0x0020
-)
-
-type fiodgnameArg struct {
-	length int32
-	pad    [4]byte
-	buf    unsafe.Pointer
-}
 
+// ifreqRename is used for renaming network interfaces on FreeBSD
 type ifreqRename struct {
 	Name [unix.IFNAMSIZ]byte
 	Data uintptr
 }
 
-type ifreqDestroy struct {
+func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (*wgTun, error) {
-	Name [unix.IFNAMSIZ]byte
+	return nil, fmt.Errorf("newTunFromFd not supported on FreeBSD")
-	pad  [16]byte
 }
 
-type ifReq struct {
+func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*wgTun, error) {
-	Name  [unix.IFNAMSIZ]byte
+	deviceName := c.GetString("tun.dev", "tun")
-	Flags uint16
+	mtu := c.GetInt("tun.mtu", DefaultMTU)
-}
 
-type ifreqMTU struct {
+	// Create WireGuard TUN device
-	Name [unix.IFNAMSIZ]byte
+	tunDevice, err := wgtun.CreateTUN(deviceName, mtu)
-	MTU  int32
-}
-
-type addrLifetime struct {
-	Expire    uint64
-	Preferred uint64
-	Vltime    uint32
-	Pltime    uint32
-}
-
-type ifreqAlias4 struct {
-	Name     [unix.IFNAMSIZ]byte
-	Addr     unix.RawSockaddrInet4
-	DstAddr  unix.RawSockaddrInet4
-	MaskAddr unix.RawSockaddrInet4
-	VHid     uint32
-}
-
-type ifreqAlias6 struct {
-	Name       [unix.IFNAMSIZ]byte
-	Addr       unix.RawSockaddrInet6
-	DstAddr    unix.RawSockaddrInet6
-	PrefixMask unix.RawSockaddrInet6
-	Flags      uint32
-	Lifetime   addrLifetime
-	VHid       uint32
-}
-
-type tun struct {
-	Device      string
-	vpnNetworks []netip.Prefix
-	MTU         int
-	Routes      atomic.Pointer[[]Route]
-	routeTree   atomic.Pointer[bart.Table[routing.Gateways]]
-	linkAddr    *netroute.LinkAddr
-	l           *logrus.Logger
-	devFd       int
-}
-
-func (t *tun) Read(to []byte) (int, error) {
-	// use readv() to read from the tunnel device, to eliminate the need for copying the buffer
-	if t.devFd < 0 {
-		return -1, syscall.EINVAL
-	}
-
-	// first 4 bytes is protocol family, in network byte order
-	head := make([]byte, 4)
-
-	iovecs := []syscall.Iovec{
-		{&head[0], 4},
-		{&to[0], uint64(len(to))},
-	}
-
-	n, _, errno := syscall.Syscall(syscall.SYS_READV, uintptr(t.devFd), uintptr(unsafe.Pointer(&iovecs[0])), uintptr(2))
-
-	var err error
-	if errno != 0 {
-		err = syscall.Errno(errno)
-	} else {
-		err = nil
-	}
-	// fix bytes read number to exclude header
-	bytesRead := int(n)
-	if bytesRead < 0 {
-		return bytesRead, err
-	} else if bytesRead < 4 {
-		return 0, err
-	} else {
-		return bytesRead - 4, err
-	}
-}
-
-// Write is only valid for single threaded use
-func (t *tun) Write(from []byte) (int, error) {
-	// use writev() to write to the tunnel device, to eliminate the need for copying the buffer
-	if t.devFd < 0 {
-		return -1, syscall.EINVAL
-	}
-
-	if len(from) <= 1 {
-		return 0, syscall.EIO
-	}
-	ipVer := from[0] >> 4
-	var head []byte
-	// first 4 bytes is protocol family, in network byte order
-	if ipVer == 4 {
-		head = []byte{0, 0, 0, syscall.AF_INET}
-	} else if ipVer == 6 {
-		head = []byte{0, 0, 0, syscall.AF_INET6}
-	} else {
-		return 0, fmt.Errorf("unable to determine IP version from packet")
-	}
-	iovecs := []syscall.Iovec{
-		{&head[0], 4},
-		{&from[0], uint64(len(from))},
-	}
-
-	n, _, errno := syscall.Syscall(syscall.SYS_WRITEV, uintptr(t.devFd), uintptr(unsafe.Pointer(&iovecs[0])), uintptr(2))
-
-	var err error
-	if errno != 0 {
-		err = syscall.Errno(errno)
-	} else {
-		err = nil
-	}
-
-	return int(n) - 4, err
-}
-
-func (t *tun) Close() error {
-	if t.devFd >= 0 {
-		err := syscall.Close(t.devFd)
 	if err != nil {
-			t.l.WithError(err).Error("Error closing device")
+		return nil, fmt.Errorf("failed to create TUN device: %w", err)
 	}
-		t.devFd = -1
 
-		c := make(chan struct{})
+	// Get the actual device name
-		go func() {
+	actualName, err := tunDevice.Name()
-			// destroying the interface can block if a read() is still pending. Do this asynchronously.
-			defer close(c)
-			s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_IP)
-			if err == nil {
-				defer syscall.Close(s)
-				ifreq := ifreqDestroy{Name: t.deviceBytes()}
-				err = ioctl(uintptr(s), syscall.SIOCIFDESTROY, uintptr(unsafe.Pointer(&ifreq)))
-			}
 	if err != nil {
-				t.l.WithError(err).Error("Error destroying tunnel")
+		tunDevice.Close()
-			}
+		return nil, fmt.Errorf("failed to get TUN device name: %w", err)
-		}()
-
-		// wait up to 1 second so we start blocking at the ioctl
-		select {
-		case <-c:
-		case <-time.After(1 * time.Second):
-		}
-	}
-
-	return nil
-}
-
-func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (*tun, error) {
-	return nil, fmt.Errorf("newTunFromFd not supported in FreeBSD")
-}
-
-func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*tun, error) {
-	// Try to open existing tun device
-	var fd int
-	var err error
-	deviceName := c.GetString("tun.dev", "")
-	if deviceName != "" {
-		fd, err = syscall.Open("/dev/"+deviceName, syscall.O_RDWR, 0)
-	}
-	if errors.Is(err, fs.ErrNotExist) || deviceName == "" {
-		// If the device doesn't already exist, request a new one and rename it
-		fd, err = syscall.Open("/dev/tun", syscall.O_RDWR, 0)
-	}
-	if err != nil {
-		return nil, err
-	}
-
-	// Read the name of the interface
-	var name [16]byte
-	arg := fiodgnameArg{length: 16, buf: unsafe.Pointer(&name)}
-	ctrlErr := ioctl(uintptr(fd), FIODGNAME, uintptr(unsafe.Pointer(&arg)))
-
-	if ctrlErr == nil {
-		// set broadcast mode and multicast
-		ifmode := uint32(unix.IFF_BROADCAST | unix.IFF_MULTICAST)
-		ctrlErr = ioctl(uintptr(fd), TUNSIFMODE, uintptr(unsafe.Pointer(&ifmode)))
-	}
-
-	if ctrlErr == nil {
-		// turn on link-layer mode, to support ipv6
-		ifhead := uint32(1)
-		ctrlErr = ioctl(uintptr(fd), TUNSIFHEAD, uintptr(unsafe.Pointer(&ifhead)))
-	}
-
-	if ctrlErr != nil {
-		return nil, err
-	}
-
-	ifName := string(bytes.TrimRight(name[:], "\x00"))
-	if deviceName == "" {
-		deviceName = ifName
 	}
 
 	// If the name doesn't match the desired interface name, rename it now
-	if ifName != deviceName {
+	if actualName != deviceName && deviceName != "" && deviceName != "tun" {
-		s, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
+		if err := renameInterface(actualName, deviceName); err != nil {
-		if err != nil {
+			tunDevice.Close()
-			return nil, err
+			return nil, fmt.Errorf("failed to rename interface from %s to %s: %w", actualName, deviceName, err)
 		}
-		defer syscall.Close(s)
+		actualName = deviceName
-
-		fd := uintptr(s)
-
-		var fromName [16]byte
-		var toName [16]byte
-		copy(fromName[:], ifName)
-		copy(toName[:], deviceName)
-
-		ifrr := ifreqRename{
-			Name: fromName,
-			Data: uintptr(unsafe.Pointer(&toName)),
 	}
 
-		// Set the device name
+	t := &wgTun{
-		ioctl(fd, syscall.SIOCSIFNAME, uintptr(unsafe.Pointer(&ifrr)))
+		tunDevice:   tunDevice,
-	}
-
-	t := &tun{
-		Device:      deviceName,
 		vpnNetworks: vpnNetworks,
-		MTU:         c.GetInt("tun.mtu", DefaultMTU),
+		MaxMTU:      mtu,
+		DefaultMTU:  mtu,
 		l:           l,
-		devFd:       fd,
 	}
 
+	// Create FreeBSD-specific route manager
+	t.routeManager = &tun{}
+
 	err = t.reload(c, true)
 	if err != nil {
+		tunDevice.Close()
 		return nil, err
 	}
 
@@ -289,180 +82,86 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (
 		}
 	})
 
+	l.WithField("name", actualName).Info("Created WireGuard TUN device")
+
 	return t, nil
 }
 
-func (t *tun) addIp(cidr netip.Prefix) error {
+func (rm *tun) Activate(t *wgTun) error {
-	if cidr.Addr().Is4() {
+	name, err := t.tunDevice.Name()
-		ifr := ifreqAlias4{
-			Name: t.deviceBytes(),
-			Addr: unix.RawSockaddrInet4{
-				Len:    unix.SizeofSockaddrInet4,
-				Family: unix.AF_INET,
-				Addr:   cidr.Addr().As4(),
-			},
-			DstAddr: unix.RawSockaddrInet4{
-				Len:    unix.SizeofSockaddrInet4,
-				Family: unix.AF_INET,
-				Addr:   getBroadcast(cidr).As4(),
-			},
-			MaskAddr: unix.RawSockaddrInet4{
-				Len:    unix.SizeofSockaddrInet4,
-				Family: unix.AF_INET,
-				Addr:   prefixToMask(cidr).As4(),
-			},
-			VHid: 0,
-		}
-		s, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
 	if err != nil {
-			return err
+		return fmt.Errorf("failed to get device name: %w", err)
-		}
-		defer syscall.Close(s)
-		// Note: unix.SIOCAIFADDR corresponds to FreeBSD's OSIOCAIFADDR
-		if err := ioctl(uintptr(s), unix.SIOCAIFADDR, uintptr(unsafe.Pointer(&ifr))); err != nil {
-			return fmt.Errorf("failed to set tun address %s: %s", cidr.Addr().String(), err)
-		}
-		return nil
 	}
 
-	if cidr.Addr().Is6() {
+	// Set the MTU
-		ifr := ifreqAlias6{
+	rm.SetMTU(t, t.MaxMTU)
-			Name: t.deviceBytes(),
-			Addr: unix.RawSockaddrInet6{
-				Len:    unix.SizeofSockaddrInet6,
-				Family: unix.AF_INET6,
-				Addr:   cidr.Addr().As16(),
-			},
-			PrefixMask: unix.RawSockaddrInet6{
-				Len:    unix.SizeofSockaddrInet6,
-				Family: unix.AF_INET6,
-				Addr:   prefixToMask(cidr).As16(),
-			},
-			Lifetime: addrLifetime{
-				Expire:    0,
-				Preferred: 0,
-				Vltime:    0xffffffff,
-				Pltime:    0xffffffff,
-			},
-			Flags: IN6_IFF_NODAD,
-		}
-		s, err := syscall.Socket(syscall.AF_INET6, syscall.SOCK_DGRAM, syscall.IPPROTO_IP)
-		if err != nil {
-			return err
-		}
-		defer syscall.Close(s)
 
-		if err := ioctl(uintptr(s), OSIOCAIFADDR_IN6, uintptr(unsafe.Pointer(&ifr))); err != nil {
+	// Add IP addresses
-			return fmt.Errorf("failed to set tun address %s: %s", cidr.Addr().String(), err)
+	for _, network := range t.vpnNetworks {
-		}
+		if err := rm.addIP(t, name, network); err != nil {
-		return nil
-	}
-
-	return fmt.Errorf("unknown address type %v", cidr)
-}
-
-func (t *tun) Activate() error {
-	// Setup our default MTU
-	err := t.setMTU()
-	if err != nil {
-		return err
-	}
-
-	linkAddr, err := getLinkAddr(t.Device)
-	if err != nil {
-		return err
-	}
-	if linkAddr == nil {
-		return fmt.Errorf("unable to discover link_addr for tun interface")
-	}
-	t.linkAddr = linkAddr
-
-	for i := range t.vpnNetworks {
-		err := t.addIp(t.vpnNetworks[i])
-		if err != nil {
 			return err
 		}
 	}
 
-	return t.addRoutes(false)
+	// Bring up the interface
+	if err := runCommandBSD("ifconfig", name, "up"); err != nil {
+		return fmt.Errorf("failed to bring up interface: %w", err)
 	}
 
-func (t *tun) setMTU() error {
+	// Set the routes
-	// Set the MTU on the device
+	if err := rm.AddRoutes(t, false); err != nil {
-	s, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
-	if err != nil {
 		return err
 	}
-	defer syscall.Close(s)
-
-	ifm := ifreqMTU{Name: t.deviceBytes(), MTU: int32(t.MTU)}
-	err = ioctl(uintptr(s), unix.SIOCSIFMTU, uintptr(unsafe.Pointer(&ifm)))
-	return err
-}
-
-func (t *tun) reload(c *config.C, initial bool) error {
-	change, routes, err := getAllRoutesFromConfig(c, t.vpnNetworks, initial)
-	if err != nil {
-		return err
-	}
-
-	if !initial && !change {
-		return nil
-	}
-
-	routeTree, err := makeRouteTree(t.l, routes, false)
-	if err != nil {
-		return err
-	}
-
-	// Teach nebula how to handle the routes before establishing them in the system table
-	oldRoutes := t.Routes.Swap(&routes)
-	t.routeTree.Store(routeTree)
-
-	if !initial {
-		// Remove first, if the system removes a wanted route hopefully it will be re-added next
-		err := t.removeRoutes(findRemovedRoutes(routes, *oldRoutes))
-		if err != nil {
-			util.LogWithContextIfNeeded("Failed to remove routes", err, t.l)
-		}
-
-		// Ensure any routes we actually want are installed
-		err = t.addRoutes(true)
-		if err != nil {
-			// Catch any stray logs
-			util.LogWithContextIfNeeded("Failed to add routes", err, t.l)
-		}
-	}
 
 	return nil
 }
 
-func (t *tun) RoutesFor(ip netip.Addr) routing.Gateways {
+func (rm *tun) SetMTU(t *wgTun, mtu int) {
-	r, _ := t.routeTree.Load().Lookup(ip)
+	name, err := t.tunDevice.Name()
-	return r
+	if err != nil {
+		t.l.WithError(err).Error("Failed to get device name for MTU set")
+		return
 	}
 
-func (t *tun) Networks() []netip.Prefix {
+	if err := runCommandBSD("ifconfig", name, "mtu", strconv.Itoa(mtu)); err != nil {
-	return t.vpnNetworks
+		t.l.WithError(err).Error("Failed to set tun mtu")
+	}
 }
 
-func (t *tun) Name() string {
+func (rm *tun) SetDefaultRoute(t *wgTun, cidr netip.Prefix) error {
-	return t.Device
+	// On FreeBSD, routes are set via ifconfig and route commands
+	return nil
 }
 
-func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
+func (rm *tun) AddRoutes(t *wgTun, logErrors bool) error {
-	return nil, fmt.Errorf("TODO: multiqueue not implemented for freebsd")
+	name, err := t.tunDevice.Name()
+	if err != nil {
+		return fmt.Errorf("failed to get device name: %w", err)
 	}
 
-func (t *tun) addRoutes(logErrors bool) error {
 	routes := *t.Routes.Load()
 	for _, r := range routes {
-		if len(r.Via) == 0 || !r.Install {
+		if !r.Install {
-			// We don't allow route MTUs so only install routes with a via
 			continue
 		}
 
-		err := addRoute(r.Cidr, t.linkAddr)
+		// Add route using route command
+		args := []string{"add"}
+
+		if r.Cidr.Addr().Is6() {
+			args = append(args, "-inet6")
+		} else {
+			args = append(args, "-inet")
+		}
+
+		args = append(args, r.Cidr.String(), "-interface", name)
+
+		if r.Metric > 0 {
+			// FreeBSD doesn't support route metrics directly like Linux
+			t.l.WithField("route", r).Warn("Route metrics are not fully supported on FreeBSD")
+		}
+
+		err := runCommandBSD("route", args...)
 		if err != nil {
 			retErr := util.NewContextualError("Failed to add route", map[string]any{"route": r}, err)
 			if logErrors {
@@ -478,142 +177,99 @@ func (t *tun) addRoutes(logErrors bool) error {
 	return nil
 }
 
-func (t *tun) removeRoutes(routes []Route) error {
+func (rm *tun) RemoveRoutes(t *wgTun, routes []Route) {
+	name, err := t.tunDevice.Name()
+	if err != nil {
+		t.l.WithError(err).Error("Failed to get device name for route removal")
+		return
+	}
+
 	for _, r := range routes {
 		if !r.Install {
 			continue
 		}
 
-		err := delRoute(r.Cidr, t.linkAddr)
+		args := []string{"delete"}
+
+		if r.Cidr.Addr().Is6() {
+			args = append(args, "-inet6")
+		} else {
+			args = append(args, "-inet")
+		}
+
+		args = append(args, r.Cidr.String(), "-interface", name)
+
+		err := runCommandBSD("route", args...)
 		if err != nil {
 			t.l.WithError(err).WithField("route", r).Error("Failed to remove route")
 		} else {
 			t.l.WithField("route", r).Info("Removed route")
 		}
 	}
-	return nil
 }
 
-func (t *tun) deviceBytes() (o [16]byte) {
+func (rm *tun) NewMultiQueueReader(t *wgTun) (io.ReadWriteCloser, error) {
-	for i, c := range t.Device {
+	// FreeBSD doesn't support multi-queue TUN devices in the same way as Linux
-		o[i] = byte(c)
+	// Return a reader that wraps the same device
-	}
+	return &wgTunReader{
-	return
+		parent:    t,
+		tunDevice: t.tunDevice,
+		offset:    0,
+		l:         t.l,
+	}, nil
 }
 
-func addRoute(prefix netip.Prefix, gateway netroute.Addr) error {
+func (rm *tun) addIP(t *wgTun, name string, network netip.Prefix) error {
-	sock, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
+	addr := network.Addr()
-	if err != nil {
-		return fmt.Errorf("unable to create AF_ROUTE socket: %v", err)
-	}
-	defer unix.Close(sock)
 
-	route := &netroute.RouteMessage{
+	if addr.Is4() {
-		Version: unix.RTM_VERSION,
+		// For IPv4: ifconfig tun0 10.0.0.1/24
-		Type:    unix.RTM_ADD,
+		if err := runCommandBSD("ifconfig", name, network.String()); err != nil {
-		Flags:   unix.RTF_UP,
+			return fmt.Errorf("failed to add IPv4 address: %w", err)
-		Seq:     1,
-	}
-
-	if prefix.Addr().Is4() {
-		route.Addrs = []netroute.Addr{
-			unix.RTAX_DST:     &netroute.Inet4Addr{IP: prefix.Masked().Addr().As4()},
-			unix.RTAX_NETMASK: &netroute.Inet4Addr{IP: prefixToMask(prefix).As4()},
-			unix.RTAX_GATEWAY: gateway,
 		}
 	} else {
-		route.Addrs = []netroute.Addr{
+		// For IPv6: ifconfig tun0 inet6 add 2001:db8::1/64
-			unix.RTAX_DST:     &netroute.Inet6Addr{IP: prefix.Masked().Addr().As16()},
+		if err := runCommandBSD("ifconfig", name, "inet6", "add", network.String()); err != nil {
-			unix.RTAX_NETMASK: &netroute.Inet6Addr{IP: prefixToMask(prefix).As16()},
+			return fmt.Errorf("failed to add IPv6 address: %w", err)
-			unix.RTAX_GATEWAY: gateway,
 		}
 	}
 
-	data, err := route.Marshal()
-	if err != nil {
-		return fmt.Errorf("failed to create route.RouteMessage: %w", err)
-	}
-
-	_, err = unix.Write(sock, data[:])
-	if err != nil {
-		if errors.Is(err, unix.EEXIST) {
-			// Try to do a change
-			route.Type = unix.RTM_CHANGE
-			data, err = route.Marshal()
-			if err != nil {
-				return fmt.Errorf("failed to create route.RouteMessage for change: %w", err)
-			}
-			_, err = unix.Write(sock, data[:])
-			fmt.Println("DOING CHANGE")
-			return err
-		}
-		return fmt.Errorf("failed to write route.RouteMessage to socket: %w", err)
-	}
-
 	return nil
 }
 
-func delRoute(prefix netip.Prefix, gateway netroute.Addr) error {
+func runCommandBSD(name string, args ...string) error {
-	sock, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
+	cmd := exec.Command(name, args...)
+	output, err := cmd.CombinedOutput()
 	if err != nil {
-		return fmt.Errorf("unable to create AF_ROUTE socket: %v", err)
+		return fmt.Errorf("%s %s failed: %w\nOutput: %s", name, strings.Join(args, " "), err, string(output))
 	}
-	defer unix.Close(sock)
+	return nil
-
-	route := netroute.RouteMessage{
-		Version: unix.RTM_VERSION,
-		Type:    unix.RTM_DELETE,
-		Seq:     1,
 }
 
-	if prefix.Addr().Is4() {
+func renameInterface(fromName, toName string) error {
-		route.Addrs = []netroute.Addr{
+	s, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
-			unix.RTAX_DST:     &netroute.Inet4Addr{IP: prefix.Masked().Addr().As4()},
+	if err != nil {
-			unix.RTAX_NETMASK: &netroute.Inet4Addr{IP: prefixToMask(prefix).As4()},
+		return fmt.Errorf("failed to create socket: %w", err)
-			unix.RTAX_GATEWAY: gateway,
-		}
-	} else {
-		route.Addrs = []netroute.Addr{
-			unix.RTAX_DST:     &netroute.Inet6Addr{IP: prefix.Masked().Addr().As16()},
-			unix.RTAX_NETMASK: &netroute.Inet6Addr{IP: prefixToMask(prefix).As16()},
-			unix.RTAX_GATEWAY: gateway,
 	}
+	defer syscall.Close(s)
+
+	fd := uintptr(s)
+
+	var fromNameBytes [unix.IFNAMSIZ]byte
+	var toNameBytes [unix.IFNAMSIZ]byte
+	copy(fromNameBytes[:], fromName)
+	copy(toNameBytes[:], toName)
+
+	ifrr := ifreqRename{
+		Name: fromNameBytes,
+		Data: uintptr(unsafe.Pointer(&toNameBytes)),
 	}
 
-	data, err := route.Marshal()
+	// Set the device name using SIOCSIFNAME ioctl
-	if err != nil {
+	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, fd, syscall.SIOCSIFNAME, uintptr(unsafe.Pointer(&ifrr)))
-		return fmt.Errorf("failed to create route.RouteMessage: %w", err)
+	if errno != 0 {
-	}
+		return fmt.Errorf("SIOCSIFNAME ioctl failed: %w", errno)
-	_, err = unix.Write(sock, data[:])
-	if err != nil {
-		return fmt.Errorf("failed to write route.RouteMessage to socket: %w", err)
 	}
 
 	return nil
 }
-
-// getLinkAddr Gets the link address for the interface of the given name
-func getLinkAddr(name string) (*netroute.LinkAddr, error) {
-	rib, err := netroute.FetchRIB(unix.AF_UNSPEC, unix.NET_RT_IFLIST, 0)
-	if err != nil {
-		return nil, err
-	}
-	msgs, err := netroute.ParseRIB(unix.NET_RT_IFLIST, rib)
-	if err != nil {
-		return nil, err
-	}
-
-	for _, m := range msgs {
-		switch m := m.(type) {
-		case *netroute.InterfaceMessage:
-			if m.Name == name {
-				sa, ok := m.Addrs[unix.RTAX_IFP].(*netroute.LinkAddr)
-				if ok {
-					return sa, nil
-				}
-			}
-		}
-	}
-
-	return nil, nil
-}

overlay/tun_linux.go

@@ -1,5 +1,5 @@
-//go:build !android && !e2e_testing
+//go:build linux && !android && !e2e_testing
-// +build !android,!e2e_testing
+// +build linux,!android,!e2e_testing
 
 package overlay
 
@@ -9,169 +9,105 @@ import (
 	"net"
 	"net/netip"
 	"os"
-	"runtime"
-	"strings"
-	"sync/atomic"
 	"time"
 	"unsafe"
 
-	"github.com/gaissmai/bart"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/routing"
 	"github.com/slackhq/nebula/util"
-	wgtun "github.com/slackhq/nebula/wgstack/tun"
 	"github.com/vishvananda/netlink"
 	"golang.org/x/sys/unix"
+	wgtun "golang.zx2c4.com/wireguard/tun"
 )
 
 type tun struct {
-	io.ReadWriteCloser
-	fd          int
-	Device      string
-	vpnNetworks []netip.Prefix
-	MaxMTU      int
-	DefaultMTU  int
-	TXQueueLen  int
 	deviceIndex               int
 	ioctlFd                   uintptr
-	wgDevice    wgtun.Device
+	txQueueLen                int
-
-	Routes                    atomic.Pointer[[]Route]
-	routeTree                 atomic.Pointer[bart.Table[routing.Gateways]]
-	routeChan                 chan struct{}
 	useSystemRoutes           bool
 	useSystemRoutesBufferSize int
-
-	l *logrus.Logger
 }
 
-func (t *tun) Networks() []netip.Prefix {
+func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, multiqueue bool) (*wgTun, error) {
-	return t.vpnNetworks
+	deviceName := c.GetString("tun.dev", "")
-}
+	mtu := c.GetInt("tun.mtu", DefaultMTU)
 
-type ifReq struct {
+	// Create WireGuard TUN device
-	Name  [16]byte
+	tunDevice, err := wgtun.CreateTUN(deviceName, mtu)
-	Flags uint16
-	pad   [8]byte
-}
-
-type ifreqMTU struct {
-	Name [16]byte
-	MTU  int32
-	pad  [8]byte
-}
-
-type ifreqQLEN struct {
-	Name  [16]byte
-	Value int32
-	pad   [8]byte
-}
-
-func newTunFromFd(c *config.C, l *logrus.Logger, deviceFd int, vpnNetworks []netip.Prefix) (*tun, error) {
-	file := os.NewFile(uintptr(deviceFd), "/dev/net/tun")
-
-	useWGDefault := runtime.GOOS == "linux"
-	useWG := c.GetBool("tun.use_wireguard_stack", c.GetBool("listen.use_wireguard_stack", useWGDefault))
-	t, err := newTunGeneric(c, l, file, vpnNetworks, useWG)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to create TUN device: %w", err)
 	}
 
-	t.Device = "tun0"
+	// Get the actual device name
-
+	actualName, err := tunDevice.Name()
-	return t, nil
-}
-
-func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, multiqueue bool) (*tun, error) {
-	fd, err := unix.Open("/dev/net/tun", os.O_RDWR, 0)
 	if err != nil {
-		// If /dev/net/tun doesn't exist, try to create it (will happen in docker)
+		tunDevice.Close()
-		if os.IsNotExist(err) {
+		return nil, fmt.Errorf("failed to get TUN device name: %w", err)
-			err = os.MkdirAll("/dev/net", 0755)
-			if err != nil {
-				return nil, fmt.Errorf("/dev/net/tun doesn't exist, failed to mkdir -p /dev/net: %w", err)
-			}
-			err = unix.Mknod("/dev/net/tun", unix.S_IFCHR|0600, int(unix.Mkdev(10, 200)))
-			if err != nil {
-				return nil, fmt.Errorf("failed to create /dev/net/tun: %w", err)
 	}
 
-			fd, err = unix.Open("/dev/net/tun", os.O_RDWR, 0)
+	t := &wgTun{
-			if err != nil {
+		tunDevice:   tunDevice,
-				return nil, fmt.Errorf("created /dev/net/tun, but still failed: %w", err)
-			}
-		} else {
-			return nil, err
-		}
-	}
-
-	var req ifReq
-	req.Flags = uint16(unix.IFF_TUN | unix.IFF_NO_PI)
-	if multiqueue {
-		req.Flags |= unix.IFF_MULTI_QUEUE
-	}
-	copy(req.Name[:], c.GetString("tun.dev", ""))
-	if err = ioctl(uintptr(fd), uintptr(unix.TUNSETIFF), uintptr(unsafe.Pointer(&req))); err != nil {
-		return nil, err
-	}
-	name := strings.Trim(string(req.Name[:]), "\x00")
-
-	file := os.NewFile(uintptr(fd), "/dev/net/tun")
-	useWGDefault := runtime.GOOS == "linux"
-	useWG := c.GetBool("tun.use_wireguard_stack", c.GetBool("listen.use_wireguard_stack", useWGDefault))
-	t, err := newTunGeneric(c, l, file, vpnNetworks, useWG)
-	if err != nil {
-		return nil, err
-	}
-
-	t.Device = name
-
-	return t, nil
-}
-
-func newTunGeneric(c *config.C, l *logrus.Logger, file *os.File, vpnNetworks []netip.Prefix, useWireguard bool) (*tun, error) {
-	var (
-		rw    io.ReadWriteCloser = file
-		fd                       = int(file.Fd())
-		wgDev wgtun.Device
-	)
-
-	if useWireguard {
-		dev, err := wgtun.CreateTUNFromFile(file, c.GetInt("tun.mtu", DefaultMTU))
-		if err != nil {
-			return nil, fmt.Errorf("failed to initialize wireguard tun device: %w", err)
-		}
-		wgDev = dev
-		rw = newWireguardTunIO(dev, c.GetInt("tun.mtu", DefaultMTU))
-		fd = int(dev.File().Fd())
-	}
-
-	t := &tun{
-		ReadWriteCloser:           rw,
-		fd:                        fd,
 		vpnNetworks: vpnNetworks,
-		TXQueueLen:                c.GetInt("tun.tx_queue", 500),
+		MaxMTU:      mtu,
-		useSystemRoutes:           c.GetBool("tun.use_system_route_table", false),
+		DefaultMTU:  mtu,
-		useSystemRoutesBufferSize: c.GetInt("tun.use_system_route_table_buffer_size", 0),
 		l:           l,
 	}
-	if wgDev != nil {
-		t.wgDevice = wgDev
-	}
-	if wgDev != nil {
-		// replace ioctl fd with device file descriptor to keep route management working
-		file = wgDev.File()
-		t.fd = int(file.Fd())
-		t.ioctlFd = file.Fd()
-	}
 
-	if t.ioctlFd == 0 {
+	// Create Linux-specific route manager
-		t.ioctlFd = file.Fd()
+	routeManager := &tun{
+		txQueueLen:                c.GetInt("tun.tx_queue", 500),
+		useSystemRoutes:           c.GetBool("tun.use_system_route_table", false),
+		useSystemRoutesBufferSize: c.GetInt("tun.use_system_route_table_buffer_size", 0),
 	}
+	t.routeManager = routeManager
 
-	err := t.reload(c, true)
+	err = t.reload(c, true)
 	if err != nil {
+		tunDevice.Close()
+		return nil, err
+	}
+
+	c.RegisterReloadCallback(func(c *config.C) {
+		err := t.reload(c, false)
+		if err != nil {
+			util.LogWithContextIfNeeded("failed to reload tun device", err, t.l)
+		}
+	})
+
+	l.WithField("name", actualName).Info("Created WireGuard TUN device")
+
+	return t, nil
+}
+
+func newTunFromFd(c *config.C, l *logrus.Logger, deviceFd int, vpnNetworks []netip.Prefix) (*wgTun, error) {
+	// Create TUN device from file descriptor
+	file := os.NewFile(uintptr(deviceFd), "/dev/net/tun")
+	mtu := c.GetInt("tun.mtu", DefaultMTU)
+	tunDevice, err := wgtun.CreateTUNFromFile(file, mtu)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create TUN device from fd: %w", err)
+	}
+
+	t := &wgTun{
+		tunDevice:   tunDevice,
+		vpnNetworks: vpnNetworks,
+		MaxMTU:      mtu,
+		DefaultMTU:  mtu,
+		l:           l,
+	}
+
+	// Create Linux-specific route manager
+	routeManager := &tun{
+		txQueueLen:                c.GetInt("tun.tx_queue", 500),
+		useSystemRoutes:           c.GetBool("tun.use_system_route_table", false),
+		useSystemRoutesBufferSize: c.GetInt("tun.use_system_route_table_buffer_size", 0),
+	}
+	t.routeManager = routeManager
+
+	err = t.reload(c, true)
+	if err != nil {
+		tunDevice.Close()
 		return nil, err
 	}
 
@@ -185,273 +121,105 @@ func newTunGeneric(c *config.C, l *logrus.Logger, file *os.File, vpnNetworks []n
 	return t, nil
 }
 
-func (t *tun) reload(c *config.C, initial bool) error {
+func (rm *tun) Activate(t *wgTun) error {
-	routeChange, routes, err := getAllRoutesFromConfig(c, t.vpnNetworks, initial)
+	name, err := t.tunDevice.Name()
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to get device name: %w", err)
 	}
 
-	if !initial && !routeChange && !c.HasChanged("tun.mtu") {
+	if t.routeManager.useSystemRoutes {
-		return nil
-	}
-
-	routeTree, err := makeRouteTree(t.l, routes, true)
-	if err != nil {
-		return err
-	}
-
-	oldDefaultMTU := t.DefaultMTU
-	oldMaxMTU := t.MaxMTU
-	newDefaultMTU := c.GetInt("tun.mtu", DefaultMTU)
-	newMaxMTU := newDefaultMTU
-	for i, r := range routes {
-		if r.MTU == 0 {
-			routes[i].MTU = newDefaultMTU
-		}
-
-		if r.MTU > t.MaxMTU {
-			newMaxMTU = r.MTU
-		}
-	}
-
-	t.MaxMTU = newMaxMTU
-	t.DefaultMTU = newDefaultMTU
-
-	// Teach nebula how to handle the routes before establishing them in the system table
-	oldRoutes := t.Routes.Swap(&routes)
-	t.routeTree.Store(routeTree)
-
-	if !initial {
-		if oldMaxMTU != newMaxMTU {
-			t.setMTU()
-			t.l.Infof("Set max MTU to %v was %v", t.MaxMTU, oldMaxMTU)
-		}
-
-		if oldDefaultMTU != newDefaultMTU {
-			for i := range t.vpnNetworks {
-				err := t.setDefaultRoute(t.vpnNetworks[i])
-				if err != nil {
-					t.l.Warn(err)
-				} else {
-					t.l.Infof("Set default MTU to %v was %v", t.DefaultMTU, oldDefaultMTU)
-				}
-			}
-		}
-
-		// Remove first, if the system removes a wanted route hopefully it will be re-added next
-		t.removeRoutes(findRemovedRoutes(routes, *oldRoutes))
-
-		// Ensure any routes we actually want are installed
-		err = t.addRoutes(true)
-		if err != nil {
-			// This should never be called since addRoutes should log its own errors in a reload condition
-			util.LogWithContextIfNeeded("Failed to refresh routes", err, t.l)
-		}
-	}
-
-	return nil
-}
-
-func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
-	fd, err := unix.Open("/dev/net/tun", os.O_RDWR, 0)
-	if err != nil {
-		return nil, err
-	}
-
-	var req ifReq
-	req.Flags = uint16(unix.IFF_TUN | unix.IFF_NO_PI | unix.IFF_MULTI_QUEUE)
-	copy(req.Name[:], t.Device)
-	if err = ioctl(uintptr(fd), uintptr(unix.TUNSETIFF), uintptr(unsafe.Pointer(&req))); err != nil {
-		return nil, err
-	}
-
-	file := os.NewFile(uintptr(fd), "/dev/net/tun")
-
-	return file, nil
-}
-
-func (t *tun) RoutesFor(ip netip.Addr) routing.Gateways {
-	r, _ := t.routeTree.Load().Lookup(ip)
-	return r
-}
-
-func (t *tun) Write(b []byte) (int, error) {
-	var nn int
-	maximum := len(b)
-
-	for {
-		n, err := unix.Write(t.fd, b[nn:maximum])
-		if n > 0 {
-			nn += n
-		}
-		if nn == len(b) {
-			return nn, err
-		}
-
-		if err != nil {
-			return nn, err
-		}
-
-		if n == 0 {
-			return nn, io.ErrUnexpectedEOF
-		}
-	}
-}
-
-func (t *tun) deviceBytes() (o [16]byte) {
-	for i, c := range t.Device {
-		o[i] = byte(c)
-	}
-	return
-}
-
-func hasNetlinkAddr(al []*netlink.Addr, x netlink.Addr) bool {
-	for i := range al {
-		if al[i].Equal(x) {
-			return true
-		}
-	}
-	return false
-}
-
-// addIPs uses netlink to add all addresses that don't exist, then it removes ones that should not be there
-func (t *tun) addIPs(link netlink.Link) error {
-	newAddrs := make([]*netlink.Addr, len(t.vpnNetworks))
-	for i := range t.vpnNetworks {
-		newAddrs[i] = &netlink.Addr{
-			IPNet: &net.IPNet{
-				IP:   t.vpnNetworks[i].Addr().AsSlice(),
-				Mask: net.CIDRMask(t.vpnNetworks[i].Bits(), t.vpnNetworks[i].Addr().BitLen()),
-			},
-			Label: t.vpnNetworks[i].Addr().Zone(),
-		}
-	}
-
-	//add all new addresses
-	for i := range newAddrs {
-		//AddrReplace still adds new IPs, but if their properties change it will change them as well
-		if err := netlink.AddrReplace(link, newAddrs[i]); err != nil {
-			return err
-		}
-	}
-
-	//iterate over remainder, remove whoever shouldn't be there
-	al, err := netlink.AddrList(link, netlink.FAMILY_ALL)
-	if err != nil {
-		return fmt.Errorf("failed to get tun address list: %s", err)
-	}
-
-	for i := range al {
-		if hasNetlinkAddr(newAddrs, al[i]) {
-			continue
-		}
-		err = netlink.AddrDel(link, &al[i])
-		if err != nil {
-			t.l.WithError(err).Error("failed to remove address from tun address list")
-		} else {
-			t.l.WithField("removed", al[i].String()).Info("removed address not listed in cert(s)")
-		}
-	}
-
-	return nil
-}
-
-func (t *tun) Activate() error {
-	devName := t.deviceBytes()
-
-	if t.useSystemRoutes {
 		t.watchRoutes()
 	}
 
+	// Get the netlink device
+	link, err := netlink.LinkByName(name)
+	if err != nil {
+		return fmt.Errorf("failed to get tun device link: %s", err)
+	}
+
+	rm.deviceIndex = link.Attrs().Index
+
+	// Open socket for ioctl operations
 	s, err := unix.Socket(
-		unix.AF_INET, //because everything we use t.ioctlFd for is address family independent, this is fine
+		unix.AF_INET,
 		unix.SOCK_DGRAM,
 		unix.IPPROTO_IP,
 	)
 	if err != nil {
 		return err
 	}
-	t.ioctlFd = uintptr(s)
+	rm.ioctlFd = uintptr(s)
 
-	// Set the device name
+	rm.SetMTU(t, t.MaxMTU)
-	ifrf := ifReq{Name: devName}
-	if err = ioctl(t.ioctlFd, unix.SIOCGIFFLAGS, uintptr(unsafe.Pointer(&ifrf))); err != nil {
-		return fmt.Errorf("failed to set tun device name: %s", err)
-	}
-
-	link, err := netlink.LinkByName(t.Device)
-	if err != nil {
-		return fmt.Errorf("failed to get tun device link: %s", err)
-	}
-
-	t.deviceIndex = link.Attrs().Index
-
-	// Setup our default MTU
-	t.setMTU()
 
 	// Set the transmit queue length
-	ifrq := ifreqQLEN{Name: devName, Value: int32(t.TXQueueLen)}
+	devName := deviceBytes(name)
-	if err = ioctl(t.ioctlFd, unix.SIOCSIFTXQLEN, uintptr(unsafe.Pointer(&ifrq))); err != nil {
+	ifrq := ifreqQLEN{Name: devName, Value: int32(rm.txQueueLen)}
+	if err = ioctl(t.routeManager.ioctlFd, unix.SIOCSIFTXQLEN, uintptr(unsafe.Pointer(&ifrq))); err != nil {
 		// If we can't set the queue length nebula will still work but it may lead to packet loss
 		t.l.WithError(err).Error("Failed to set tun tx queue length")
 	}
 
+	// Disable IPv6 link-local address generation
 	const modeNone = 1
 	if err = netlink.LinkSetIP6AddrGenMode(link, modeNone); err != nil {
 		t.l.WithError(err).Warn("Failed to disable link local address generation")
 	}
 
-	if err = t.addIPs(link); err != nil {
+	// Add IP addresses
+	if err = t.routeManager.addIPs(t, link); err != nil {
 		return err
 	}
 
 	// Bring up the interface
-	ifrf.Flags = ifrf.Flags | unix.IFF_UP
+	if err = netlink.LinkSetUp(link); err != nil {
-	if err = ioctl(t.ioctlFd, unix.SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifrf))); err != nil {
 		return fmt.Errorf("failed to bring the tun device up: %s", err)
 	}
 
-	//set route MTU
+	// Set route MTU
 	for i := range t.vpnNetworks {
-		if err = t.setDefaultRoute(t.vpnNetworks[i]); err != nil {
+		if err = t.routeManager.SetDefaultRoute(t, t.vpnNetworks[i]); err != nil {
 			return fmt.Errorf("failed to set default route MTU: %w", err)
 		}
 	}
 
 	// Set the routes
-	if err = t.addRoutes(false); err != nil {
+	if err = t.routeManager.AddRoutes(t, false); err != nil {
 		return err
 	}
 
-	// Run the interface
-	ifrf.Flags = ifrf.Flags | unix.IFF_UP | unix.IFF_RUNNING
-	if err = ioctl(t.ioctlFd, unix.SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifrf))); err != nil {
-		return fmt.Errorf("failed to run tun device: %s", err)
-	}
-
 	return nil
 }
 
-func (t *tun) setMTU() {
+func (rm *tun) SetMTU(t *wgTun, mtu int) {
-	// Set the MTU on the device
+	name, err := t.tunDevice.Name()
-	ifm := ifreqMTU{Name: t.deviceBytes(), MTU: int32(t.MaxMTU)}
+	if err != nil {
-	if err := ioctl(t.ioctlFd, unix.SIOCSIFMTU, uintptr(unsafe.Pointer(&ifm))); err != nil {
+		t.l.WithError(err).Error("Failed to get device name for MTU set")
-		// This is currently a non fatal condition because the route table must have the MTU set appropriately as well
+		return
+	}
+
+	link, err := netlink.LinkByName(name)
+	if err != nil {
+		t.l.WithError(err).Error("Failed to get link for MTU set")
+		return
+	}
+
+	if err := netlink.LinkSetMTU(link, mtu); err != nil {
 		t.l.WithError(err).Error("Failed to set tun mtu")
 	}
 }
 
-func (t *tun) setDefaultRoute(cidr netip.Prefix) error {
+func (rm *tun) SetDefaultRoute(t *wgTun, cidr netip.Prefix) error {
 	dr := &net.IPNet{
 		IP:   cidr.Masked().Addr().AsSlice(),
 		Mask: net.CIDRMask(cidr.Bits(), cidr.Addr().BitLen()),
 	}
 
 	nr := netlink.Route{
-		LinkIndex: t.deviceIndex,
+		LinkIndex: t.routeManager.deviceIndex,
 		Dst:       dr,
 		MTU:       t.DefaultMTU,
-		AdvMSS:    t.advMSS(Route{}),
+		AdvMSS:    advMSS(Route{}, t.DefaultMTU, t.MaxMTU),
 		Scope:     unix.RT_SCOPE_LINK,
 		Src:       net.IP(cidr.Addr().AsSlice()),
 		Protocol:  unix.RTPROT_KERNEL,
@@ -461,7 +229,7 @@ func (t *tun) setDefaultRoute(cidr netip.Prefix) error {
 	err := netlink.RouteReplace(&nr)
 	if err != nil {
 		t.l.WithError(err).WithField("cidr", cidr).Warn("Failed to set default route MTU, retrying")
-		//retry twice more -- on some systems there appears to be a race condition where if we set routes too soon, netlink says `invalid argument`
+		// Retry twice more
 		for i := 0; i < 2; i++ {
 			time.Sleep(100 * time.Millisecond)
 			err = netlink.RouteReplace(&nr)
@@ -479,8 +247,7 @@ func (t *tun) setDefaultRoute(cidr netip.Prefix) error {
 	return nil
 }
 
-func (t *tun) addRoutes(logErrors bool) error {
+func (rm *tun) AddRoutes(t *wgTun, logErrors bool) error {
-	// Path routes
 	routes := *t.Routes.Load()
 	for _, r := range routes {
 		if !r.Install {
@@ -493,10 +260,10 @@ func (t *tun) addRoutes(logErrors bool) error {
 		}
 
 		nr := netlink.Route{
-			LinkIndex: t.deviceIndex,
+			LinkIndex: t.routeManager.deviceIndex,
 			Dst:       dr,
 			MTU:       r.MTU,
-			AdvMSS:    t.advMSS(r),
+			AdvMSS:    advMSS(r, t.DefaultMTU, t.MaxMTU),
 			Scope:     unix.RT_SCOPE_LINK,
 		}
 
@@ -520,7 +287,7 @@ func (t *tun) addRoutes(logErrors bool) error {
 	return nil
 }
 
-func (t *tun) removeRoutes(routes []Route) {
+func (rm *tun) RemoveRoutes(t *wgTun, routes []Route) {
 	for _, r := range routes {
 		if !r.Install {
 			continue
@@ -532,10 +299,10 @@ func (t *tun) removeRoutes(routes []Route) {
 		}
 
 		nr := netlink.Route{
-			LinkIndex: t.deviceIndex,
+			LinkIndex: t.routeManager.deviceIndex,
 			Dst:       dr,
 			MTU:       r.MTU,
-			AdvMSS:    t.advMSS(r),
+			AdvMSS:    advMSS(r, t.DefaultMTU, t.MaxMTU),
 			Scope:     unix.RT_SCOPE_LINK,
 		}
 
@@ -552,30 +319,105 @@ func (t *tun) removeRoutes(routes []Route) {
 	}
 }
 
-func (t *tun) Name() string {
+func (rm *tun) NewMultiQueueReader(t *wgTun) (io.ReadWriteCloser, error) {
-	return t.Device
+	// For Linux with WireGuard TUN, we can reuse the same device
+	// The vectorized I/O will handle batching
+	return &wgTunReader{
+		parent:    t,
+		tunDevice: t.tunDevice,
+		offset:    0,
+		l:         t.l,
+	}, nil
 }
 
-func (t *tun) advMSS(r Route) int {
+func deviceBytes(name string) [16]byte {
+	var o [16]byte
+	for i, c := range name {
+		if i >= 16 {
+			break
+		}
+		o[i] = byte(c)
+	}
+	return o
+}
+
+func advMSS(r Route, defaultMTU, maxMTU int) int {
 	mtu := r.MTU
 	if r.MTU == 0 {
-		mtu = t.DefaultMTU
+		mtu = defaultMTU
 	}
 
 	// We only need to set advmss if the route MTU does not match the device MTU
-	if mtu != t.MaxMTU {
+	if mtu != maxMTU {
 		return mtu - 40
 	}
 	return 0
 }
 
-func (t *tun) watchRoutes() {
+type ifreqQLEN struct {
+	Name  [16]byte
+	Value int32
+	pad   [8]byte
+}
+
+func hasNetlinkAddr(al []*netlink.Addr, x netlink.Addr) bool {
+	for i := range al {
+		if al[i].Equal(x) {
+			return true
+		}
+	}
+	return false
+}
+
+func (rm *tun) addIPs(t *wgTun, link netlink.Link) error {
+	newAddrs := make([]*netlink.Addr, len(t.vpnNetworks))
+	for i := range t.vpnNetworks {
+		newAddrs[i] = &netlink.Addr{
+			IPNet: &net.IPNet{
+				IP:   t.vpnNetworks[i].Addr().AsSlice(),
+				Mask: net.CIDRMask(t.vpnNetworks[i].Bits(), t.vpnNetworks[i].Addr().BitLen()),
+			},
+			Label: t.vpnNetworks[i].Addr().Zone(),
+		}
+	}
+
+	// Add all new addresses
+	for i := range newAddrs {
+		if err := netlink.AddrReplace(link, newAddrs[i]); err != nil {
+			return err
+		}
+	}
+
+	// Iterate over remainder, remove whoever shouldn't be there
+	al, err := netlink.AddrList(link, netlink.FAMILY_ALL)
+	if err != nil {
+		return fmt.Errorf("failed to get tun address list: %s", err)
+	}
+
+	for i := range al {
+		if hasNetlinkAddr(newAddrs, al[i]) {
+			continue
+		}
+		err = netlink.AddrDel(link, &al[i])
+		if err != nil {
+			t.l.WithError(err).Error("failed to remove address from tun address list")
+		} else {
+			t.l.WithField("removed", al[i].String()).Info("removed address not listed in cert(s)")
+		}
+	}
+
+	return nil
+}
+
+// watchRoutes monitors system route changes
+func (t *wgTun) watchRoutes() {
+
 	rch := make(chan netlink.RouteUpdate)
 	doneChan := make(chan struct{})
 
 	netlinkOptions := netlink.RouteSubscribeOptions{
-		ReceiveBufferSize:      t.useSystemRoutesBufferSize,
+		ReceiveBufferSize:      t.routeManager.useSystemRoutesBufferSize,
-		ReceiveBufferForceSize: t.useSystemRoutesBufferSize != 0,
+		ReceiveBufferForceSize: t.routeManager.useSystemRoutesBufferSize != 0,
 		ErrorCallback:          func(e error) { t.l.WithError(e).Errorf("netlink error") },
 	}
 
@@ -593,87 +435,19 @@ func (t *tun) watchRoutes() {
 				if ok {
 					t.updateRoutes(r)
 				} else {
-					// may be should do something here as
-					// netlink stops sending updates
 					return
 				}
 			case <-doneChan:
-				// netlink.RouteSubscriber will close the rch for us
 				return
 			}
 		}
 	}()
 }
 
-func (t *tun) isGatewayInVpnNetworks(gwAddr netip.Addr) bool {
+func (t *wgTun) updateRoutes(r netlink.RouteUpdate) {
-	withinNetworks := false
+	gateways := t.getGatewaysFromRoute(&r.Route, t.routeManager.deviceIndex)
-	for i := range t.vpnNetworks {
-		if t.vpnNetworks[i].Contains(gwAddr) {
-			withinNetworks = true
-			break
-		}
-	}
-
-	return withinNetworks
-}
-
-func (t *tun) getGatewaysFromRoute(r *netlink.Route) routing.Gateways {
-
-	var gateways routing.Gateways
-
-	link, err := netlink.LinkByName(t.Device)
-	if err != nil {
-		t.l.WithField("Devicename", t.Device).Error("Ignoring route update: failed to get link by name")
-		return gateways
-	}
-
-	// If this route is relevant to our interface and there is a gateway then add it
-	if r.LinkIndex == link.Attrs().Index && len(r.Gw) > 0 {
-		gwAddr, ok := netip.AddrFromSlice(r.Gw)
-		if !ok {
-			t.l.WithField("route", r).Debug("Ignoring route update, invalid gateway address")
-		} else {
-			gwAddr = gwAddr.Unmap()
-
-			if !t.isGatewayInVpnNetworks(gwAddr) {
-				// Gateway isn't in our overlay network, ignore
-				t.l.WithField("route", r).Debug("Ignoring route update, not in our network")
-			} else {
-				gateways = append(gateways, routing.NewGateway(gwAddr, 1))
-			}
-		}
-	}
-
-	for _, p := range r.MultiPath {
-		// If this route is relevant to our interface and there is a gateway then add it
-		if p.LinkIndex == link.Attrs().Index && len(p.Gw) > 0 {
-			gwAddr, ok := netip.AddrFromSlice(p.Gw)
-			if !ok {
-				t.l.WithField("route", r).Debug("Ignoring multipath route update, invalid gateway address")
-			} else {
-				gwAddr = gwAddr.Unmap()
-
-				if !t.isGatewayInVpnNetworks(gwAddr) {
-					// Gateway isn't in our overlay network, ignore
-					t.l.WithField("route", r).Debug("Ignoring route update, not in our network")
-				} else {
-					// p.Hops+1 = weight of the route
-					gateways = append(gateways, routing.NewGateway(gwAddr, p.Hops+1))
-				}
-			}
-		}
-	}
-
-	routing.CalculateBucketsForGateways(gateways)
-	return gateways
-}
-
-func (t *tun) updateRoutes(r netlink.RouteUpdate) {
-
-	gateways := t.getGatewaysFromRoute(&r.Route)
 
 	if len(gateways) == 0 {
-		// No gateways relevant to our network, no routing changes required.
 		t.l.WithField("route", r).Debug("Ignoring route update, no gateways")
 		return
 	}
@@ -697,7 +471,6 @@ func (t *tun) updateRoutes(r netlink.RouteUpdate) {
 	if r.Type == unix.RTM_NEWROUTE {
 		t.l.WithField("destination", dst).WithField("via", gateways).Info("Adding route")
 		newTree.Insert(dst, gateways)
-
 	} else {
 		t.l.WithField("destination", dst).WithField("via", gateways).Info("Removing route")
 		newTree.Delete(dst)
@@ -705,26 +478,71 @@ func (t *tun) updateRoutes(r netlink.RouteUpdate) {
 	t.routeTree.Store(newTree)
 }
 
-func (t *tun) Close() error {
+func (t *wgTun) getGatewaysFromRoute(r *netlink.Route, deviceIndex int) routing.Gateways {
-	if t.routeChan != nil {
+	var gateways routing.Gateways
-		close(t.routeChan)
+
+	name, err := t.tunDevice.Name()
+	if err != nil {
+		t.l.Error("Ignoring route update: failed to get device name")
+		return gateways
 	}
 
-	if t.ReadWriteCloser != nil {
+	link, err := netlink.LinkByName(name)
-		_ = t.ReadWriteCloser.Close()
+	if err != nil {
+		t.l.WithField("DeviceName", name).Error("Ignoring route update: failed to get link by name")
+		return gateways
 	}
 
-	if t.wgDevice != nil {
+	// If this route is relevant to our interface and there is a gateway then add it
-		_ = t.wgDevice.Close()
+	if r.LinkIndex == link.Attrs().Index && len(r.Gw) > 0 {
-		if t.ioctlFd > 0 {
+		gwAddr, ok := netip.AddrFromSlice(r.Gw)
-			// underlying fd already closed by the device
+		if !ok {
-			t.ioctlFd = 0
+			t.l.WithField("route", r).Debug("Ignoring route update, invalid gateway address")
+		} else {
+			gwAddr = gwAddr.Unmap()
+
+			if !t.isGatewayInVpnNetworks(gwAddr) {
+				t.l.WithField("route", r).Debug("Ignoring route update, not in our network")
+			} else {
+				gateways = append(gateways, routing.NewGateway(gwAddr, 1))
+			}
 		}
 	}
 
-	if t.ioctlFd > 0 {
+	for _, p := range r.MultiPath {
-		_ = os.NewFile(t.ioctlFd, "ioctlFd").Close()
+		if p.LinkIndex == link.Attrs().Index && len(p.Gw) > 0 {
+			gwAddr, ok := netip.AddrFromSlice(p.Gw)
+			if !ok {
+				t.l.WithField("route", r).Debug("Ignoring multipath route update, invalid gateway address")
+			} else {
+				gwAddr = gwAddr.Unmap()
+
+				if !t.isGatewayInVpnNetworks(gwAddr) {
+					t.l.WithField("route", r).Debug("Ignoring route update, not in our network")
+				} else {
+					gateways = append(gateways, routing.NewGateway(gwAddr, p.Hops+1))
+				}
+			}
+		}
 	}
 
+	routing.CalculateBucketsForGateways(gateways)
+	return gateways
+}
+
+func (t *wgTun) isGatewayInVpnNetworks(gwAddr netip.Addr) bool {
+	for i := range t.vpnNetworks {
+		if t.vpnNetworks[i].Contains(gwAddr) {
+			return true
+		}
+	}
+	return false
+}
+
+func ioctl(a1, a2, a3 uintptr) error {
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, a1, a2, a3)
+	if errno != 0 {
+		return errno
+	}
 	return nil
 }

overlay/tun_linux_batch.go

@@ -1,56 +0,0 @@
-//go:build linux && !android && !e2e_testing
-
-package overlay
-
-import "fmt"
-
-func (t *tun) batchIO() (*wireguardTunIO, bool) {
-	io, ok := t.ReadWriteCloser.(*wireguardTunIO)
-	return io, ok
-}
-
-func (t *tun) ReadIntoBatch(pool *PacketPool) ([]*Packet, error) {
-	io, ok := t.batchIO()
-	if !ok {
-		return nil, fmt.Errorf("wireguard batch I/O not enabled")
-	}
-	return io.ReadIntoBatch(pool)
-}
-
-func (t *tun) WriteBatch(packets []*Packet) (int, error) {
-	io, ok := t.batchIO()
-	if ok {
-		return io.WriteBatch(packets)
-	}
-	for _, pkt := range packets {
-		if pkt == nil {
-			continue
-		}
-		if _, err := t.Write(pkt.Payload()[:pkt.Len]); err != nil {
-			return 0, err
-		}
-		pkt.Release()
-	}
-	return len(packets), nil
-}
-
-func (t *tun) BatchHeadroom() int {
-	if io, ok := t.batchIO(); ok {
-		return io.BatchHeadroom()
-	}
-	return 0
-}
-
-func (t *tun) BatchPayloadCap() int {
-	if io, ok := t.batchIO(); ok {
-		return io.BatchPayloadCap()
-	}
-	return 0
-}
-
-func (t *tun) BatchSize() int {
-	if io, ok := t.batchIO(); ok {
-		return io.BatchSize()
-	}
-	return 1
-}

overlay/tun_linux_test.go

@@ -7,25 +7,26 @@ import "testing"
 
 var runAdvMSSTests = []struct {
 	name       string
-	tun      *tun
+	defaultMTU int
+	maxMTU     int
 	r          Route
 	expected   int
 }{
 	// Standard case, default MTU is the device max MTU
-	{"default", &tun{DefaultMTU: 1440, MaxMTU: 1440}, Route{}, 0},
+	{"default", 1440, 1440, Route{}, 0},
-	{"default-min", &tun{DefaultMTU: 1440, MaxMTU: 1440}, Route{MTU: 1440}, 0},
+	{"default-min", 1440, 1440, Route{MTU: 1440}, 0},
-	{"default-low", &tun{DefaultMTU: 1440, MaxMTU: 1440}, Route{MTU: 1200}, 1160},
+	{"default-low", 1440, 1440, Route{MTU: 1200}, 1160},
 
 	// Case where we have a route MTU set higher than the default
-	{"route", &tun{DefaultMTU: 1440, MaxMTU: 8941}, Route{}, 1400},
+	{"route", 1440, 8941, Route{}, 1400},
-	{"route-min", &tun{DefaultMTU: 1440, MaxMTU: 8941}, Route{MTU: 1440}, 1400},
+	{"route-min", 1440, 8941, Route{MTU: 1440}, 1400},
-	{"route-high", &tun{DefaultMTU: 1440, MaxMTU: 8941}, Route{MTU: 8941}, 0},
+	{"route-high", 1440, 8941, Route{MTU: 8941}, 0},
 }
 
 func TestTunAdvMSS(t *testing.T) {
 	for _, tt := range runAdvMSSTests {
 		t.Run(tt.name, func(t *testing.T) {
-			o := tt.tun.advMSS(tt.r)
+			o := advMSS(tt.r, tt.defaultMTU, tt.maxMTU)
 			if o != tt.expected {
 				t.Errorf("got %d, want %d", o, tt.expected)
 			}

overlay/tun_netbsd.go

@@ -547,3 +547,41 @@ func delRoute(prefix netip.Prefix, gateways []netip.Prefix) error {
 
 	return nil
 }
+
+func ioctl(a1, a2, a3 uintptr) error {
+	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, a1, a2, a3)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+func prefixToMask(prefix netip.Prefix) netip.Addr {
+	bits := prefix.Bits()
+	if prefix.Addr().Is4() {
+		mask := ^uint32(0) << (32 - bits)
+		return netip.AddrFrom4([4]byte{
+			byte(mask >> 24),
+			byte(mask >> 16),
+			byte(mask >> 8),
+			byte(mask),
+		})
+	}
+	var mask [16]byte
+	for i := 0; i < bits/8; i++ {
+		mask[i] = 0xff
+	}
+	if bits%8 != 0 {
+		mask[bits/8] = ^byte(0) << (8 - bits%8)
+	}
+	return netip.AddrFrom16(mask)
+}
+
+func selectGateway(prefix netip.Prefix, gateways []netip.Prefix) (netip.Prefix, error) {
+	for _, gw := range gateways {
+		if prefix.Addr().Is4() == gw.Addr().Is4() {
+			return gw, nil
+		}
+	}
+	return netip.Prefix{}, fmt.Errorf("no suitable gateway found for prefix %v", prefix)
+}

overlay/tun_notwin.go

@@ -1,14 +0,0 @@
-//go:build !windows
-// +build !windows
-
-package overlay
-
-import "syscall"
-
-func ioctl(a1, a2, a3 uintptr) error {
-	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, a1, a2, a3)
-	if errno != 0 {
-		return errno
-	}
-	return nil
-}

overlay/tun_openbsd.go

@@ -1,104 +1,59 @@
-//go:build !e2e_testing
+//go:build openbsd && !e2e_testing
-// +build !e2e_testing
+// +build openbsd,!e2e_testing
 
 package overlay
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"net/netip"
-	"os"
+	"os/exec"
-	"regexp"
+	"strconv"
-	"sync/atomic"
+	"strings"
-	"syscall"
-	"unsafe"
 
-	"github.com/gaissmai/bart"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/routing"
 	"github.com/slackhq/nebula/util"
-	netroute "golang.org/x/net/route"
+	wgtun "golang.zx2c4.com/wireguard/tun"
-	"golang.org/x/sys/unix"
 )
 
-const (
+type tun struct{}
-	SIOCAIFADDR_IN6 = 0x8080691a
-)
 
-type ifreqAlias4 struct {
+func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (*wgTun, error) {
-	Name     [unix.IFNAMSIZ]byte
+	return nil, fmt.Errorf("newTunFromFd not supported on OpenBSD")
-	Addr     unix.RawSockaddrInet4
-	DstAddr  unix.RawSockaddrInet4
-	MaskAddr unix.RawSockaddrInet4
 }
 
-type ifreqAlias6 struct {
+func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*wgTun, error) {
-	Name       [unix.IFNAMSIZ]byte
+	deviceName := c.GetString("tun.dev", "tun")
-	Addr       unix.RawSockaddrInet6
+	mtu := c.GetInt("tun.mtu", DefaultMTU)
-	DstAddr    unix.RawSockaddrInet6
-	PrefixMask unix.RawSockaddrInet6
-	Flags      uint32
-	Lifetime   [2]uint32
-}
 
-type ifreq struct {
+	// Create WireGuard TUN device
-	Name [unix.IFNAMSIZ]byte
+	tunDevice, err := wgtun.CreateTUN(deviceName, mtu)
-	data int
-}
-
-type tun struct {
-	Device      string
-	vpnNetworks []netip.Prefix
-	MTU         int
-	Routes      atomic.Pointer[[]Route]
-	routeTree   atomic.Pointer[bart.Table[routing.Gateways]]
-	l           *logrus.Logger
-	f           *os.File
-	fd          int
-	// cache out buffer since we need to prepend 4 bytes for tun metadata
-	out []byte
-}
-
-var deviceNameRE = regexp.MustCompile(`^tun[0-9]+$`)
-
-func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (*tun, error) {
-	return nil, fmt.Errorf("newTunFromFd not supported in openbsd")
-}
-
-func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*tun, error) {
-	// Try to open tun device
-	var err error
-	deviceName := c.GetString("tun.dev", "")
-	if deviceName == "" {
-		return nil, fmt.Errorf("a device name in the format of /dev/tunN must be specified")
-	}
-	if !deviceNameRE.MatchString(deviceName) {
-		return nil, fmt.Errorf("a device name in the format of /dev/tunN must be specified")
-	}
-
-	fd, err := unix.Open("/dev/"+deviceName, os.O_RDWR, 0)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to create TUN device: %w", err)
 	}
 
-	err = unix.SetNonblock(fd, true)
+	// Get the actual device name
+	actualName, err := tunDevice.Name()
 	if err != nil {
-		l.WithError(err).Warn("Failed to set the tun device as nonblocking")
+		tunDevice.Close()
+		return nil, fmt.Errorf("failed to get TUN device name: %w", err)
 	}
 
-	t := &tun{
+	t := &wgTun{
-		f:           os.NewFile(uintptr(fd), ""),
+		tunDevice:   tunDevice,
-		fd:          fd,
-		Device:      deviceName,
 		vpnNetworks: vpnNetworks,
-		MTU:         c.GetInt("tun.mtu", DefaultMTU),
+		MaxMTU:      mtu,
+		DefaultMTU:  mtu,
 		l:           l,
 	}
 
+	// Create OpenBSD-specific route manager
+	t.routeManager = &tun{}
+
 	err = t.reload(c, true)
 	if err != nil {
+		tunDevice.Close()
 		return nil, err
 	}
 
@@ -109,221 +64,86 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (
 		}
 	})
 
+	l.WithField("name", actualName).Info("Created WireGuard TUN device")
+
 	return t, nil
 }
 
-func (t *tun) Close() error {
+func (rm *tun) Activate(t *wgTun) error {
-	if t.f != nil {
+	name, err := t.tunDevice.Name()
-		if err := t.f.Close(); err != nil {
-			return fmt.Errorf("error closing tun file: %w", err)
-		}
-
-		// t.f.Close should have handled it for us but let's be extra sure
-		_ = unix.Close(t.fd)
-	}
-	return nil
-}
-
-func (t *tun) Read(to []byte) (int, error) {
-	buf := make([]byte, len(to)+4)
-
-	n, err := t.f.Read(buf)
-
-	copy(to, buf[4:])
-	return n - 4, err
-}
-
-// Write is only valid for single threaded use
-func (t *tun) Write(from []byte) (int, error) {
-	buf := t.out
-	if cap(buf) < len(from)+4 {
-		buf = make([]byte, len(from)+4)
-		t.out = buf
-	}
-	buf = buf[:len(from)+4]
-
-	if len(from) == 0 {
-		return 0, syscall.EIO
-	}
-
-	// Determine the IP Family for the NULL L2 Header
-	ipVer := from[0] >> 4
-	if ipVer == 4 {
-		buf[3] = syscall.AF_INET
-	} else if ipVer == 6 {
-		buf[3] = syscall.AF_INET6
-	} else {
-		return 0, fmt.Errorf("unable to determine IP version from packet")
-	}
-
-	copy(buf[4:], from)
-
-	n, err := t.f.Write(buf)
-	return n - 4, err
-}
-
-func (t *tun) addIp(cidr netip.Prefix) error {
-	if cidr.Addr().Is4() {
-		var req ifreqAlias4
-		req.Name = t.deviceBytes()
-		req.Addr = unix.RawSockaddrInet4{
-			Len:    unix.SizeofSockaddrInet4,
-			Family: unix.AF_INET,
-			Addr:   cidr.Addr().As4(),
-		}
-		req.DstAddr = unix.RawSockaddrInet4{
-			Len:    unix.SizeofSockaddrInet4,
-			Family: unix.AF_INET,
-			Addr:   cidr.Addr().As4(),
-		}
-		req.MaskAddr = unix.RawSockaddrInet4{
-			Len:    unix.SizeofSockaddrInet4,
-			Family: unix.AF_INET,
-			Addr:   prefixToMask(cidr).As4(),
-		}
-
-		s, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
 	if err != nil {
+		return fmt.Errorf("failed to get device name: %w", err)
+	}
+
+	// Set the MTU
+	rm.SetMTU(t, t.MaxMTU)
+
+	// Add IP addresses
+	for _, network := range t.vpnNetworks {
+		if err := rm.addIP(t, name, network); err != nil {
 			return err
 		}
-		defer syscall.Close(s)
-
-		if err := ioctl(uintptr(s), unix.SIOCAIFADDR, uintptr(unsafe.Pointer(&req))); err != nil {
-			return fmt.Errorf("failed to set tun address %s: %s", cidr.Addr(), err)
 	}
 
-		err = addRoute(cidr, t.vpnNetworks)
+	// Bring up the interface
-		if err != nil {
+	if err := runCommandBSD("ifconfig", name, "up"); err != nil {
-			return fmt.Errorf("failed to set route for vpn network %v: %w", cidr, err)
+		return fmt.Errorf("failed to bring up interface: %w", err)
+	}
+
+	// Set the routes
+	if err := rm.AddRoutes(t, false); err != nil {
+		return err
 	}
 
 	return nil
 }
 
-	if cidr.Addr().Is6() {
+func (rm *tun) SetMTU(t *wgTun, mtu int) {
-		var req ifreqAlias6
+	name, err := t.tunDevice.Name()
-		req.Name = t.deviceBytes()
-		req.Addr = unix.RawSockaddrInet6{
-			Len:    unix.SizeofSockaddrInet6,
-			Family: unix.AF_INET6,
-			Addr:   cidr.Addr().As16(),
-		}
-		req.PrefixMask = unix.RawSockaddrInet6{
-			Len:    unix.SizeofSockaddrInet6,
-			Family: unix.AF_INET6,
-			Addr:   prefixToMask(cidr).As16(),
-		}
-		req.Lifetime[0] = 0xffffffff
-		req.Lifetime[1] = 0xffffffff
-
-		s, err := unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, unix.IPPROTO_IP)
 	if err != nil {
-			return err
+		t.l.WithError(err).Error("Failed to get device name for MTU set")
-		}
+		return
-		defer syscall.Close(s)
-
-		if err := ioctl(uintptr(s), SIOCAIFADDR_IN6, uintptr(unsafe.Pointer(&req))); err != nil {
-			return fmt.Errorf("failed to set tun address %s: %s", cidr.Addr().String(), err)
 	}
 
+	if err := runCommandBSD("ifconfig", name, "mtu", strconv.Itoa(mtu)); err != nil {
+		t.l.WithError(err).Error("Failed to set tun mtu")
+	}
+}
+
+func (rm *tun) SetDefaultRoute(t *wgTun, cidr netip.Prefix) error {
+	// On OpenBSD, routes are set via ifconfig and route commands
 	return nil
 }
 
-	return fmt.Errorf("unknown address type %v", cidr)
+func (rm *tun) AddRoutes(t *wgTun, logErrors bool) error {
-}
+	name, err := t.tunDevice.Name()
-
-func (t *tun) Activate() error {
-	err := t.doIoctlByName(unix.SIOCSIFMTU, uint32(t.MTU))
 	if err != nil {
-		return fmt.Errorf("failed to set tun mtu: %w", err)
+		return fmt.Errorf("failed to get device name: %w", err)
 	}
 
-	for i := range t.vpnNetworks {
-		err = t.addIp(t.vpnNetworks[i])
-		if err != nil {
-			return err
-		}
-	}
-
-	return t.addRoutes(false)
-}
-
-func (t *tun) doIoctlByName(ctl uintptr, value uint32) error {
-	s, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
-	if err != nil {
-		return err
-	}
-	defer syscall.Close(s)
-
-	ir := ifreq{Name: t.deviceBytes(), data: int(value)}
-	err = ioctl(uintptr(s), ctl, uintptr(unsafe.Pointer(&ir)))
-	return err
-}
-
-func (t *tun) reload(c *config.C, initial bool) error {
-	change, routes, err := getAllRoutesFromConfig(c, t.vpnNetworks, initial)
-	if err != nil {
-		return err
-	}
-
-	if !initial && !change {
-		return nil
-	}
-
-	routeTree, err := makeRouteTree(t.l, routes, false)
-	if err != nil {
-		return err
-	}
-
-	// Teach nebula how to handle the routes before establishing them in the system table
-	oldRoutes := t.Routes.Swap(&routes)
-	t.routeTree.Store(routeTree)
-
-	if !initial {
-		// Remove first, if the system removes a wanted route hopefully it will be re-added next
-		err := t.removeRoutes(findRemovedRoutes(routes, *oldRoutes))
-		if err != nil {
-			util.LogWithContextIfNeeded("Failed to remove routes", err, t.l)
-		}
-
-		// Ensure any routes we actually want are installed
-		err = t.addRoutes(true)
-		if err != nil {
-			// Catch any stray logs
-			util.LogWithContextIfNeeded("Failed to add routes", err, t.l)
-		}
-	}
-
-	return nil
-}
-
-func (t *tun) RoutesFor(ip netip.Addr) routing.Gateways {
-	r, _ := t.routeTree.Load().Lookup(ip)
-	return r
-}
-
-func (t *tun) Networks() []netip.Prefix {
-	return t.vpnNetworks
-}
-
-func (t *tun) Name() string {
-	return t.Device
-}
-
-func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
-	return nil, fmt.Errorf("TODO: multiqueue not implemented for openbsd")
-}
-
-func (t *tun) addRoutes(logErrors bool) error {
 	routes := *t.Routes.Load()
-
 	for _, r := range routes {
-		if len(r.Via) == 0 || !r.Install {
+		if !r.Install {
-			// We don't allow route MTUs so only install routes with a via
 			continue
 		}
 
-		err := addRoute(r.Cidr, t.vpnNetworks)
+		// Add route using route command
+		args := []string{"add"}
+
+		if r.Cidr.Addr().Is6() {
+			args = append(args, "-inet6")
+		} else {
+			args = append(args, "-inet")
+		}
+
+		args = append(args, r.Cidr.String(), "-interface", name)
+
+		if r.Metric > 0 {
+			// OpenBSD doesn't support route metrics directly like Linux
+			t.l.WithField("route", r).Warn("Route metrics are not fully supported on OpenBSD")
+		}
+
+		err := runCommandBSD("route", args...)
 		if err != nil {
 			retErr := util.NewContextualError("Failed to add route", map[string]any{"route": r}, err)
 			if logErrors {
@@ -339,131 +159,71 @@ func (t *tun) addRoutes(logErrors bool) error {
 	return nil
 }
 
-func (t *tun) removeRoutes(routes []Route) error {
+func (rm *tun) RemoveRoutes(t *wgTun, routes []Route) {
+	name, err := t.tunDevice.Name()
+	if err != nil {
+		t.l.WithError(err).Error("Failed to get device name for route removal")
+		return
+	}
+
 	for _, r := range routes {
 		if !r.Install {
 			continue
 		}
 
-		err := delRoute(r.Cidr, t.vpnNetworks)
+		args := []string{"delete"}
+
+		if r.Cidr.Addr().Is6() {
+			args = append(args, "-inet6")
+		} else {
+			args = append(args, "-inet")
+		}
+
+		args = append(args, r.Cidr.String(), "-interface", name)
+
+		err := runCommandBSD("route", args...)
 		if err != nil {
 			t.l.WithError(err).WithField("route", r).Error("Failed to remove route")
 		} else {
 			t.l.WithField("route", r).Info("Removed route")
 		}
 	}
-	return nil
 }
 
-func (t *tun) deviceBytes() (o [16]byte) {
+func (rm *tun) NewMultiQueueReader(t *wgTun) (io.ReadWriteCloser, error) {
-	for i, c := range t.Device {
+	// OpenBSD doesn't support multi-queue TUN devices in the same way as Linux
-		o[i] = byte(c)
+	// Return a reader that wraps the same device
-	}
+	return &wgTunReader{
-	return
+		parent:    t,
+		tunDevice: t.tunDevice,
+		offset:    0,
+		l:         t.l,
+	}, nil
 }
 
-func addRoute(prefix netip.Prefix, gateways []netip.Prefix) error {
+func (rm *tun) addIP(t *wgTun, name string, network netip.Prefix) error {
-	sock, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
+	addr := network.Addr()
-	if err != nil {
-		return fmt.Errorf("unable to create AF_ROUTE socket: %v", err)
-	}
-	defer unix.Close(sock)
 
-	route := &netroute.RouteMessage{
+	if addr.Is4() {
-		Version: unix.RTM_VERSION,
+		// For IPv4: ifconfig tun0 10.0.0.1/24
-		Type:    unix.RTM_ADD,
+		if err := runCommandBSD("ifconfig", name, network.String()); err != nil {
-		Flags:   unix.RTF_UP | unix.RTF_GATEWAY,
+			return fmt.Errorf("failed to add IPv4 address: %w", err)
-		Seq:     1,
-	}
-
-	if prefix.Addr().Is4() {
-		gw, err := selectGateway(prefix, gateways)
-		if err != nil {
-			return err
-		}
-		route.Addrs = []netroute.Addr{
-			unix.RTAX_DST:     &netroute.Inet4Addr{IP: prefix.Masked().Addr().As4()},
-			unix.RTAX_NETMASK: &netroute.Inet4Addr{IP: prefixToMask(prefix).As4()},
-			unix.RTAX_GATEWAY: &netroute.Inet4Addr{IP: gw.Addr().As4()},
 		}
 	} else {
-		gw, err := selectGateway(prefix, gateways)
+		// For IPv6: ifconfig tun0 inet6 add 2001:db8::1/64
-		if err != nil {
+		if err := runCommandBSD("ifconfig", name, "inet6", "add", network.String()); err != nil {
-			return err
+			return fmt.Errorf("failed to add IPv6 address: %w", err)
 		}
-		route.Addrs = []netroute.Addr{
-			unix.RTAX_DST:     &netroute.Inet6Addr{IP: prefix.Masked().Addr().As16()},
-			unix.RTAX_NETMASK: &netroute.Inet6Addr{IP: prefixToMask(prefix).As16()},
-			unix.RTAX_GATEWAY: &netroute.Inet6Addr{IP: gw.Addr().As16()},
-		}
-	}
-
-	data, err := route.Marshal()
-	if err != nil {
-		return fmt.Errorf("failed to create route.RouteMessage: %w", err)
-	}
-
-	_, err = unix.Write(sock, data[:])
-	if err != nil {
-		if errors.Is(err, unix.EEXIST) {
-			// Try to do a change
-			route.Type = unix.RTM_CHANGE
-			data, err = route.Marshal()
-			if err != nil {
-				return fmt.Errorf("failed to create route.RouteMessage for change: %w", err)
-			}
-			_, err = unix.Write(sock, data[:])
-			return err
-		}
-		return fmt.Errorf("failed to write route.RouteMessage to socket: %w", err)
 	}
 
 	return nil
 }
 
-func delRoute(prefix netip.Prefix, gateways []netip.Prefix) error {
+func runCommandBSD(name string, args ...string) error {
-	sock, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
+	cmd := exec.Command(name, args...)
+	output, err := cmd.CombinedOutput()
 	if err != nil {
-		return fmt.Errorf("unable to create AF_ROUTE socket: %v", err)
+		return fmt.Errorf("%s %s failed: %w\nOutput: %s", name, strings.Join(args, " "), err, string(output))
 	}
-	defer unix.Close(sock)
-
-	route := netroute.RouteMessage{
-		Version: unix.RTM_VERSION,
-		Type:    unix.RTM_DELETE,
-		Seq:     1,
-	}
-
-	if prefix.Addr().Is4() {
-		gw, err := selectGateway(prefix, gateways)
-		if err != nil {
-			return err
-		}
-		route.Addrs = []netroute.Addr{
-			unix.RTAX_DST:     &netroute.Inet4Addr{IP: prefix.Masked().Addr().As4()},
-			unix.RTAX_NETMASK: &netroute.Inet4Addr{IP: prefixToMask(prefix).As4()},
-			unix.RTAX_GATEWAY: &netroute.Inet4Addr{IP: gw.Addr().As4()},
-		}
-	} else {
-		gw, err := selectGateway(prefix, gateways)
-		if err != nil {
-			return err
-		}
-		route.Addrs = []netroute.Addr{
-			unix.RTAX_DST:     &netroute.Inet6Addr{IP: prefix.Masked().Addr().As16()},
-			unix.RTAX_NETMASK: &netroute.Inet6Addr{IP: prefixToMask(prefix).As16()},
-			unix.RTAX_GATEWAY: &netroute.Inet6Addr{IP: gw.Addr().As16()},
-		}
-	}
-
-	data, err := route.Marshal()
-	if err != nil {
-		return fmt.Errorf("failed to create route.RouteMessage: %w", err)
-	}
-	_, err = unix.Write(sock, data[:])
-	if err != nil {
-		return fmt.Errorf("failed to write route.RouteMessage to socket: %w", err)
-	}
-
 	return nil
 }

overlay/tun_wg.go

@@ -0,0 +1,242 @@
+//go:build !android && !netbsd && !e2e_testing
+// +build !android,!netbsd,!e2e_testing
+
+package overlay
+
+import (
+	"fmt"
+	"io"
+	"net/netip"
+	"sync/atomic"
+
+	"github.com/gaissmai/bart"
+	"github.com/sirupsen/logrus"
+	"github.com/slackhq/nebula/config"
+	"github.com/slackhq/nebula/routing"
+	"github.com/slackhq/nebula/util"
+	wgtun "golang.zx2c4.com/wireguard/tun"
+)
+
+// wgTun wraps a WireGuard TUN device and implements the overlay.Device interface
+type wgTun struct {
+	tunDevice   wgtun.Device
+	vpnNetworks []netip.Prefix
+	MaxMTU      int
+	DefaultMTU  int
+
+	Routes    atomic.Pointer[[]Route]
+	routeTree atomic.Pointer[bart.Table[routing.Gateways]]
+	routeChan chan struct{}
+
+	// Platform-specific route management
+	routeManager *tun
+
+	l *logrus.Logger
+}
+
+// BatchReader interface for readers that support vectorized I/O
+type BatchReader interface {
+	BatchRead(buffers [][]byte, sizes []int) (int, error)
+}
+
+// BatchWriter interface for writers that support vectorized I/O
+type BatchWriter interface {
+	BatchWrite(packets [][]byte) (int, error)
+}
+
+// wgTunReader wraps a single TUN queue for multi-queue support
+type wgTunReader struct {
+	parent    *wgTun
+	tunDevice wgtun.Device
+	offset    int
+	l         *logrus.Logger
+}
+
+func (t *wgTun) Networks() []netip.Prefix {
+	return t.vpnNetworks
+}
+
+func (t *wgTun) Name() string {
+	name, err := t.tunDevice.Name()
+	if err != nil {
+		t.l.WithError(err).Error("Failed to get TUN device name")
+		return "unknown"
+	}
+	return name
+}
+
+func (t *wgTun) RoutesFor(ip netip.Addr) routing.Gateways {
+	r, _ := t.routeTree.Load().Lookup(ip)
+	return r
+}
+
+func (t *wgTun) Activate() error {
+	if t.routeManager == nil {
+		return fmt.Errorf("route manager not initialized")
+	}
+	return t.routeManager.Activate(t)
+}
+
+// Read implements single-packet read for backward compatibility
+func (t *wgTun) Read(b []byte) (int, error) {
+	bufs := [][]byte{b}
+	sizes := []int{0}
+	n, err := t.tunDevice.Read(bufs, sizes, 0)
+	if err != nil {
+		return 0, err
+	}
+	if n == 0 {
+		return 0, io.ErrNoProgress
+	}
+	return sizes[0], nil
+}
+
+// Write implements single-packet write for backward compatibility
+func (t *wgTun) Write(b []byte) (int, error) {
+	bufs := [][]byte{b}
+	offset := 0
+
+	// WireGuard TUN expects the packet data to start at offset 0
+	n, err := t.tunDevice.Write(bufs, offset)
+	if err != nil {
+		return 0, err
+	}
+	if n == 0 {
+		return 0, io.ErrShortWrite
+	}
+	return len(b), nil
+}
+
+func (t *wgTun) Close() error {
+	if t.routeChan != nil {
+		close(t.routeChan)
+	}
+
+	if t.tunDevice != nil {
+		return t.tunDevice.Close()
+	}
+
+	return nil
+}
+
+func (t *wgTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
+	// For WireGuard TUN, we need to create separate TUN device instances for multi-queue
+	// The platform-specific implementation will handle this
+	if t.routeManager == nil {
+		return nil, fmt.Errorf("route manager not initialized for multi-queue reader")
+	}
+
+	return t.routeManager.NewMultiQueueReader(t)
+}
+
+func (t *wgTun) reload(c *config.C, initial bool) error {
+	routeChange, routes, err := getAllRoutesFromConfig(c, t.vpnNetworks, initial)
+	if err != nil {
+		return err
+	}
+
+	if !initial && !routeChange && !c.HasChanged("tun.mtu") {
+		return nil
+	}
+
+	routeTree, err := makeRouteTree(t.l, routes, true)
+	if err != nil {
+		return err
+	}
+
+	oldDefaultMTU := t.DefaultMTU
+	oldMaxMTU := t.MaxMTU
+	newDefaultMTU := c.GetInt("tun.mtu", DefaultMTU)
+	newMaxMTU := newDefaultMTU
+	for i, r := range routes {
+		if r.MTU == 0 {
+			routes[i].MTU = newDefaultMTU
+		}
+
+		if r.MTU > t.MaxMTU {
+			newMaxMTU = r.MTU
+		}
+	}
+
+	t.MaxMTU = newMaxMTU
+	t.DefaultMTU = newDefaultMTU
+
+	// Teach nebula how to handle the routes before establishing them in the system table
+	oldRoutes := t.Routes.Swap(&routes)
+	t.routeTree.Store(routeTree)
+
+	if !initial && t.routeManager != nil {
+		if oldMaxMTU != newMaxMTU {
+			t.routeManager.SetMTU(t, t.MaxMTU)
+			t.l.Infof("Set max MTU to %v was %v", t.MaxMTU, oldMaxMTU)
+		}
+
+		if oldDefaultMTU != newDefaultMTU {
+			for i := range t.vpnNetworks {
+				err := t.routeManager.SetDefaultRoute(t, t.vpnNetworks[i])
+				if err != nil {
+					t.l.Warn(err)
+				} else {
+					t.l.Infof("Set default MTU to %v was %v", t.DefaultMTU, oldDefaultMTU)
+				}
+			}
+		}
+
+		// Remove first, if the system removes a wanted route hopefully it will be re-added next
+		t.routeManager.RemoveRoutes(t, findRemovedRoutes(routes, *oldRoutes))
+
+		// Ensure any routes we actually want are installed
+		err = t.routeManager.AddRoutes(t, true)
+		if err != nil {
+			// This should never be called since AddRoutes should log its own errors in a reload condition
+			util.LogWithContextIfNeeded("Failed to refresh routes", err, t.l)
+		}
+	}
+
+	return nil
+}
+
+// BatchRead reads multiple packets from the TUN device using vectorized I/O
+// The caller provides buffers and sizes slices, and this function returns the number of packets read.
+func (r *wgTunReader) BatchRead(buffers [][]byte, sizes []int) (int, error) {
+	return r.tunDevice.Read(buffers, sizes, r.offset)
+}
+
+// Read implements io.Reader for wgTunReader (single packet for compatibility)
+func (r *wgTunReader) Read(b []byte) (int, error) {
+	bufs := [][]byte{b}
+	sizes := []int{0}
+	n, err := r.tunDevice.Read(bufs, sizes, r.offset)
+	if err != nil {
+		return 0, err
+	}
+	if n == 0 {
+		return 0, io.ErrNoProgress
+	}
+	return sizes[0], nil
+}
+
+// Write implements io.Writer for wgTunReader
+func (r *wgTunReader) Write(b []byte) (int, error) {
+	bufs := [][]byte{b}
+	n, err := r.tunDevice.Write(bufs, r.offset)
+	if err != nil {
+		return 0, err
+	}
+	if n == 0 {
+		return 0, io.ErrShortWrite
+	}
+	return len(b), nil
+}
+
+// BatchWrite writes multiple packets to the TUN device using vectorized I/O
+func (r *wgTunReader) BatchWrite(packets [][]byte) (int, error) {
+	return r.tunDevice.Write(packets, r.offset)
+}
+
+func (r *wgTunReader) Close() error {
+	if r.tunDevice != nil {
+		return r.tunDevice.Close()
+	}
+	return nil
+}

overlay/tun_windows.go

@@ -1,84 +1,77 @@
-//go:build !e2e_testing
+//go:build windows && !e2e_testing
-// +build !e2e_testing
+// +build windows,!e2e_testing
 
 package overlay
 
 import (
 	"crypto"
+	"encoding/binary"
 	"fmt"
 	"io"
 	"net/netip"
-	"os"
-	"path/filepath"
-	"runtime"
-	"sync/atomic"
-	"syscall"
-	"unsafe"
 
-	"github.com/gaissmai/bart"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/routing"
 	"github.com/slackhq/nebula/util"
-	"github.com/slackhq/nebula/wintun"
 	"golang.org/x/sys/windows"
+	wgtun "golang.zx2c4.com/wireguard/tun"
 	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
 )
 
 const tunGUIDLabel = "Fixed Nebula Windows GUID v1"
 
-type winTun struct {
+type tun struct {
-	Device      string
+	luid winipcfg.LUID
-	vpnNetworks []netip.Prefix
-	MTU         int
-	Routes      atomic.Pointer[[]Route]
-	routeTree   atomic.Pointer[bart.Table[routing.Gateways]]
-	l           *logrus.Logger
-
-	tun *wintun.NativeTun
 }
 
-func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (Device, error) {
+func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ []netip.Prefix) (*wgTun, error) {
 	return nil, fmt.Errorf("newTunFromFd not supported in Windows")
 }
 
-func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*winTun, error) {
+func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (*wgTun, error) {
-	err := checkWinTunExists()
+	deviceName := c.GetString("tun.dev", "Nebula")
+	mtu := c.GetInt("tun.mtu", DefaultMTU)
+
+	// Create WireGuard TUN device
+	tunDevice, err := wgtun.CreateTUN(deviceName, mtu)
 	if err != nil {
-		return nil, fmt.Errorf("can not load the wintun driver: %w", err)
+		return nil, fmt.Errorf("failed to create TUN device: %w", err)
 	}
 
-	deviceName := c.GetString("tun.dev", "")
+	// Get the actual device name
-	guid, err := generateGUIDByDeviceName(deviceName)
+	actualName, err := tunDevice.Name()
 	if err != nil {
-		return nil, fmt.Errorf("generate GUID failed: %w", err)
+		tunDevice.Close()
+		return nil, fmt.Errorf("failed to get TUN device name: %w", err)
 	}
 
-	t := &winTun{
+	t := &wgTun{
-		Device:      deviceName,
+		tunDevice:   tunDevice,
 		vpnNetworks: vpnNetworks,
-		MTU:         c.GetInt("tun.mtu", DefaultMTU),
+		MaxMTU:      mtu,
+		DefaultMTU:  mtu,
 		l:           l,
 	}
 
+	// Create Windows-specific route manager
+	rm := &tun{}
+
+	// Get LUID from the TUN device
+	// The WireGuard TUN device on Windows should provide a LUID() method
+	if nativeTun, ok := tunDevice.(interface{ LUID() uint64 }); ok {
+		rm.luid = winipcfg.LUID(nativeTun.LUID())
+	} else {
+		tunDevice.Close()
+		return nil, fmt.Errorf("failed to get LUID from TUN device")
+	}
+	t.routeManager = rm
+
 	err = t.reload(c, true)
 	if err != nil {
+		tunDevice.Close()
 		return nil, err
 	}
 
-	var tunDevice wintun.Device
-	tunDevice, err = wintun.CreateTUNWithRequestedGUID(deviceName, guid, t.MTU)
-	if err != nil {
-		// Windows 10 has an issue with unclean shutdowns not fully cleaning up the wintun device.
-		// Trying a second time resolves the issue.
-		l.WithError(err).Debug("Failed to create wintun device, retrying")
-		tunDevice, err = wintun.CreateTUNWithRequestedGUID(deviceName, guid, t.MTU)
-		if err != nil {
-			return nil, fmt.Errorf("create TUN device failed: %w", err)
-		}
-	}
-	t.tun = tunDevice.(*wintun.NativeTun)
-
 	c.RegisterReloadCallback(func(c *config.C) {
 		err := t.reload(c, false)
 		if err != nil {
@@ -86,206 +79,140 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, _ bool) (
 		}
 	})
 
+	l.WithField("name", actualName).Info("Created WireGuard TUN device")
+
 	return t, nil
 }
 
-func (t *winTun) reload(c *config.C, initial bool) error {
+func (rm *tun) Activate(t *wgTun) error {
-	change, routes, err := getAllRoutesFromConfig(c, t.vpnNetworks, initial)
+	// Set MTU
+	err := rm.setMTU(t, t.MaxMTU)
 	if err != nil {
+		return fmt.Errorf("failed to set MTU: %w", err)
+	}
+
+	// Add IP addresses
+	for _, network := range t.vpnNetworks {
+		if err := rm.addIP(t, network); err != nil {
 			return err
 		}
-
-	if !initial && !change {
-		return nil
 	}
 
-	routeTree, err := makeRouteTree(t.l, routes, false)
+	// Add routes
-	if err != nil {
+	if err := rm.AddRoutes(t, false); err != nil {
-		return err
-	}
-
-	// Teach nebula how to handle the routes before establishing them in the system table
-	oldRoutes := t.Routes.Swap(&routes)
-	t.routeTree.Store(routeTree)
-
-	if !initial {
-		// Remove first, if the system removes a wanted route hopefully it will be re-added next
-		err := t.removeRoutes(findRemovedRoutes(routes, *oldRoutes))
-		if err != nil {
-			util.LogWithContextIfNeeded("Failed to remove routes", err, t.l)
-		}
-
-		// Ensure any routes we actually want are installed
-		err = t.addRoutes(true)
-		if err != nil {
-			// Catch any stray logs
-			util.LogWithContextIfNeeded("Failed to add routes", err, t.l)
-		}
-	}
-
-	return nil
-}
-
-func (t *winTun) Activate() error {
-	luid := winipcfg.LUID(t.tun.LUID())
-
-	err := luid.SetIPAddresses(t.vpnNetworks)
-	if err != nil {
-		return fmt.Errorf("failed to set address: %w", err)
-	}
-
-	err = t.addRoutes(false)
-	if err != nil {
 		return err
 	}
 
 	return nil
 }
 
-func (t *winTun) addRoutes(logErrors bool) error {
+func (rm *tun) SetMTU(t *wgTun, mtu int) {
-	luid := winipcfg.LUID(t.tun.LUID())
+	if err := rm.setMTU(t, mtu); err != nil {
+		t.l.WithError(err).Error("Failed to set MTU")
+	}
+}
+
+func (rm *tun) setMTU(t *wgTun, mtu int) error {
+	// Set MTU using winipcfg
+	// Note: MTU setting on Windows TUN devices may be handled by the driver
+	// For now, we'll skip explicit MTU setting as the WireGuard TUN handles it
+	return nil
+}
+
+func (rm *tun) SetDefaultRoute(t *wgTun, cidr netip.Prefix) error {
+	// On Windows, routes are managed differently
+	return nil
+}
+
+func (rm *tun) AddRoutes(t *wgTun, logErrors bool) error {
 	routes := *t.Routes.Load()
-	foundDefault4 := false
-
 	for _, r := range routes {
-		if len(r.Via) == 0 || !r.Install {
+		if !r.Install {
-			// We don't allow route MTUs so only install routes with a via
 			continue
 		}
 
-		// Add our unsafe route
+		if r.MTU > 0 {
-		// Windows does not support multipath routes natively, so we install only a single route.
+			// Windows route MTU is not directly supported
-		// This is not a problem as traffic will always be sent to Nebula which handles the multipath routing internally.
+			t.l.WithField("route", r).Debug("Route MTU is not supported on Windows")
-		// In effect this provides multipath routing support to windows supporting loadbalancing and redundancy.
+		}
-		err := luid.AddRoute(r.Cidr, r.Via[0].Addr(), uint32(r.Metric))
+
+		// Use winipcfg to add the route
+		// The rm.luid should have the AddRoute method from winipcfg
+		if len(r.Via) == 0 {
+			t.l.WithField("route", r).Warn("Route has no via address, skipping")
+			continue
+		}
+
+		err := rm.luid.AddRoute(r.Cidr, r.Via[0].Addr(), uint32(r.Metric))
 		if err != nil {
 			retErr := util.NewContextualError("Failed to add route", map[string]any{"route": r}, err)
 			if logErrors {
 				retErr.Log(t.l)
-				continue
 			} else {
 				return retErr
 			}
 		} else {
 			t.l.WithField("route", r).Info("Added route")
 		}
-
-		if !foundDefault4 {
-			if r.Cidr.Bits() == 0 && r.Cidr.Addr().BitLen() == 32 {
-				foundDefault4 = true
-			}
-		}
 	}
 
-	ipif, err := luid.IPInterface(windows.AF_INET)
-	if err != nil {
-		return fmt.Errorf("failed to get ip interface: %w", err)
-	}
-
-	ipif.NLMTU = uint32(t.MTU)
-	if foundDefault4 {
-		ipif.UseAutomaticMetric = false
-		ipif.Metric = 0
-	}
-
-	if err := ipif.Set(); err != nil {
-		return fmt.Errorf("failed to set ip interface: %w", err)
-	}
 	return nil
 }
 
-func (t *winTun) removeRoutes(routes []Route) error {
+func (rm *tun) RemoveRoutes(t *wgTun, routes []Route) {
-	luid := winipcfg.LUID(t.tun.LUID())
-
 	for _, r := range routes {
 		if !r.Install {
 			continue
 		}
 
-		// See comment on luid.AddRoute
+		if len(r.Via) == 0 {
-		err := luid.DeleteRoute(r.Cidr, r.Via[0].Addr())
+			continue
+		}
+
+		err := rm.luid.DeleteRoute(r.Cidr, r.Via[0].Addr())
 		if err != nil {
 			t.l.WithError(err).WithField("route", r).Error("Failed to remove route")
 		} else {
 			t.l.WithField("route", r).Info("Removed route")
 		}
 	}
+}
+
+func (rm *tun) NewMultiQueueReader(t *wgTun) (io.ReadWriteCloser, error) {
+	// Windows doesn't support multi-queue TUN devices
+	// Return a reader that wraps the same device
+	return &wgTunReader{
+		parent:    t,
+		tunDevice: t.tunDevice,
+		offset:    0,
+		l:         t.l,
+	}, nil
+}
+
+func (rm *tun) addIP(t *wgTun, network netip.Prefix) error {
+	// Add IP address using winipcfg
+	// SetIPAddresses expects a slice of prefixes
+	err := rm.luid.SetIPAddresses([]netip.Prefix{network})
+	if err != nil {
+		return fmt.Errorf("failed to add IP address %s: %w", network, err)
+	}
 	return nil
 }
 
-func (t *winTun) RoutesFor(ip netip.Addr) routing.Gateways {
+// generateGUIDByDeviceName generates a GUID based on the device name
-	r, _ := t.routeTree.Load().Lookup(ip)
+func generateGUIDByDeviceName(deviceName string) (*windows.GUID, error) {
-	return r
+	// Hash the device name to create a deterministic GUID
+	h := crypto.SHA256.New()
+	h.Write([]byte(tunGUIDLabel))
+	h.Write([]byte(deviceName))
+	sum := h.Sum(nil)
+
+	guid := &windows.GUID{
+		Data1: binary.LittleEndian.Uint32(sum[0:4]),
+		Data2: binary.LittleEndian.Uint16(sum[4:6]),
+		Data3: binary.LittleEndian.Uint16(sum[6:8]),
 	}
+	copy(guid.Data4[:], sum[8:16])
 
-func (t *winTun) Networks() []netip.Prefix {
+	return guid, nil
-	return t.vpnNetworks
-}
-
-func (t *winTun) Name() string {
-	return t.Device
-}
-
-func (t *winTun) Read(b []byte) (int, error) {
-	return t.tun.Read(b, 0)
-}
-
-func (t *winTun) Write(b []byte) (int, error) {
-	return t.tun.Write(b, 0)
-}
-
-func (t *winTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
-	return nil, fmt.Errorf("TODO: multiqueue not implemented for windows")
-}
-
-func (t *winTun) Close() error {
-	// It seems that the Windows networking stack doesn't like it when we destroy interfaces that have active routes,
-	// so to be certain, just remove everything before destroying.
-	luid := winipcfg.LUID(t.tun.LUID())
-	_ = luid.FlushRoutes(windows.AF_INET)
-	_ = luid.FlushIPAddresses(windows.AF_INET)
-
-	_ = luid.FlushRoutes(windows.AF_INET6)
-	_ = luid.FlushIPAddresses(windows.AF_INET6)
-
-	_ = luid.FlushDNS(windows.AF_INET)
-	_ = luid.FlushDNS(windows.AF_INET6)
-
-	return t.tun.Close()
-}
-
-func generateGUIDByDeviceName(name string) (*windows.GUID, error) {
-	// GUID is 128 bit
-	hash := crypto.MD5.New()
-
-	_, err := hash.Write([]byte(tunGUIDLabel))
-	if err != nil {
-		return nil, err
-	}
-
-	_, err = hash.Write([]byte(name))
-	if err != nil {
-		return nil, err
-	}
-
-	sum := hash.Sum(nil)
-
-	return (*windows.GUID)(unsafe.Pointer(&sum[0])), nil
-}
-
-func checkWinTunExists() error {
-	myPath, err := os.Executable()
-	if err != nil {
-		return err
-	}
-
-	arch := runtime.GOARCH
-	switch arch {
-	case "386":
-		//NOTE: wintun bundles 386 as x86
-		arch = "x86"
-	}
-
-	_, err = syscall.LoadDLL(filepath.Join(filepath.Dir(myPath), "dist", "windows", "wintun", "bin", arch, "wintun.dll"))
-	return err
 }

overlay/wireguard_tun_linux.go

@@ -1,220 +0,0 @@
-//go:build linux && !android && !e2e_testing
-
-package overlay
-
-import (
-	"fmt"
-	"sync"
-
-	wgtun "github.com/slackhq/nebula/wgstack/tun"
-)
-
-type wireguardTunIO struct {
-	dev       wgtun.Device
-	mtu       int
-	batchSize int
-
-	readMu      sync.Mutex
-	readBuffers [][]byte
-	readLens    []int
-	legacyBuf   []byte
-
-	writeMu      sync.Mutex
-	writeBuf     []byte
-	writeWrap    [][]byte
-	writeBuffers [][]byte
-}
-
-func newWireguardTunIO(dev wgtun.Device, mtu int) *wireguardTunIO {
-	batch := dev.BatchSize()
-	if batch <= 0 {
-		batch = 1
-	}
-	if mtu <= 0 {
-		mtu = DefaultMTU
-	}
-	return &wireguardTunIO{
-		dev:       dev,
-		mtu:       mtu,
-		batchSize: batch,
-		readLens:  make([]int, batch),
-		legacyBuf: make([]byte, wgtun.VirtioNetHdrLen+mtu),
-		writeBuf:  make([]byte, wgtun.VirtioNetHdrLen+mtu),
-		writeWrap: make([][]byte, 1),
-	}
-}
-
-func (w *wireguardTunIO) Read(p []byte) (int, error) {
-	w.readMu.Lock()
-	defer w.readMu.Unlock()
-
-	bufs := w.readBuffers
-	if len(bufs) == 0 {
-		bufs = [][]byte{w.legacyBuf}
-		w.readBuffers = bufs
-	}
-	n, err := w.dev.Read(bufs[:1], w.readLens[:1], wgtun.VirtioNetHdrLen)
-	if err != nil {
-		return 0, err
-	}
-	if n == 0 {
-		return 0, nil
-	}
-	length := w.readLens[0]
-	copy(p, w.legacyBuf[wgtun.VirtioNetHdrLen:wgtun.VirtioNetHdrLen+length])
-	return length, nil
-}
-
-func (w *wireguardTunIO) Write(p []byte) (int, error) {
-	if len(p) > w.mtu {
-		return 0, fmt.Errorf("wireguard tun: payload exceeds MTU (%d > %d)", len(p), w.mtu)
-	}
-	w.writeMu.Lock()
-	defer w.writeMu.Unlock()
-	buf := w.writeBuf[:wgtun.VirtioNetHdrLen+len(p)]
-	for i := 0; i < wgtun.VirtioNetHdrLen; i++ {
-		buf[i] = 0
-	}
-	copy(buf[wgtun.VirtioNetHdrLen:], p)
-	w.writeWrap[0] = buf
-	n, err := w.dev.Write(w.writeWrap, wgtun.VirtioNetHdrLen)
-	if err != nil {
-		return n, err
-	}
-	return len(p), nil
-}
-
-func (w *wireguardTunIO) ReadIntoBatch(pool *PacketPool) ([]*Packet, error) {
-	if pool == nil {
-		return nil, fmt.Errorf("wireguard tun: packet pool is nil")
-	}
-
-	w.readMu.Lock()
-	defer w.readMu.Unlock()
-
-	if len(w.readBuffers) < w.batchSize {
-		w.readBuffers = make([][]byte, w.batchSize)
-	}
-	if len(w.readLens) < w.batchSize {
-		w.readLens = make([]int, w.batchSize)
-	}
-
-	packets := make([]*Packet, w.batchSize)
-	requiredHeadroom := w.BatchHeadroom()
-	requiredPayload := w.BatchPayloadCap()
-	headroom := 0
-	for i := 0; i < w.batchSize; i++ {
-		pkt := pool.Get()
-		if pkt == nil {
-			releasePackets(packets[:i])
-			return nil, fmt.Errorf("wireguard tun: packet pool returned nil packet")
-		}
-		if pkt.Capacity() < requiredPayload {
-			pkt.Release()
-			releasePackets(packets[:i])
-			return nil, fmt.Errorf("wireguard tun: packet capacity %d below required %d", pkt.Capacity(), requiredPayload)
-		}
-		if i == 0 {
-			headroom = pkt.Offset
-			if headroom < requiredHeadroom {
-				pkt.Release()
-				releasePackets(packets[:i])
-				return nil, fmt.Errorf("wireguard tun: packet headroom %d below virtio requirement %d", headroom, requiredHeadroom)
-			}
-		} else if pkt.Offset != headroom {
-			pkt.Release()
-			releasePackets(packets[:i])
-			return nil, fmt.Errorf("wireguard tun: inconsistent packet headroom (%d != %d)", pkt.Offset, headroom)
-		}
-		packets[i] = pkt
-		w.readBuffers[i] = pkt.Buf
-	}
-
-	n, err := w.dev.Read(w.readBuffers[:w.batchSize], w.readLens[:w.batchSize], headroom)
-	if err != nil {
-		releasePackets(packets)
-		return nil, err
-	}
-	if n == 0 {
-		releasePackets(packets)
-		return nil, nil
-	}
-	for i := 0; i < n; i++ {
-		packets[i].Len = w.readLens[i]
-	}
-	for i := n; i < w.batchSize; i++ {
-		packets[i].Release()
-		packets[i] = nil
-	}
-	return packets[:n], nil
-}
-
-func (w *wireguardTunIO) WriteBatch(packets []*Packet) (int, error) {
-	if len(packets) == 0 {
-		return 0, nil
-	}
-	requiredHeadroom := w.BatchHeadroom()
-	offset := packets[0].Offset
-	if offset < requiredHeadroom {
-		releasePackets(packets)
-		return 0, fmt.Errorf("wireguard tun: packet offset %d smaller than required headroom %d", offset, requiredHeadroom)
-	}
-	for _, pkt := range packets {
-		if pkt == nil {
-			continue
-		}
-		if pkt.Offset != offset {
-			releasePackets(packets)
-			return 0, fmt.Errorf("wireguard tun: mixed packet offsets not supported")
-		}
-		limit := pkt.Offset + pkt.Len
-		if limit > len(pkt.Buf) {
-			releasePackets(packets)
-			return 0, fmt.Errorf("wireguard tun: packet length %d exceeds buffer capacity %d", pkt.Len, len(pkt.Buf)-pkt.Offset)
-		}
-	}
-	w.writeMu.Lock()
-	defer w.writeMu.Unlock()
-
-	if len(w.writeBuffers) < len(packets) {
-		w.writeBuffers = make([][]byte, len(packets))
-	}
-	for i, pkt := range packets {
-		if pkt == nil {
-			w.writeBuffers[i] = nil
-			continue
-		}
-		limit := pkt.Offset + pkt.Len
-		w.writeBuffers[i] = pkt.Buf[:limit]
-	}
-	n, err := w.dev.Write(w.writeBuffers[:len(packets)], offset)
-	if err != nil {
-		return n, err
-	}
-	releasePackets(packets)
-	return n, nil
-}
-
-func (w *wireguardTunIO) BatchHeadroom() int {
-	return wgtun.VirtioNetHdrLen
-}
-
-func (w *wireguardTunIO) BatchPayloadCap() int {
-	return w.mtu
-}
-
-func (w *wireguardTunIO) BatchSize() int {
-	return w.batchSize
-}
-
-func (w *wireguardTunIO) Close() error {
-	return nil
-}
-
-func releasePackets(pkts []*Packet) {
-	for _, pkt := range pkts {
-		if pkt != nil {
-			pkt.Release()
-		}
-	}
-}

pki.go

@@ -100,36 +100,41 @@ func (p *PKI) reloadCerts(c *config.C, initial bool) *util.ContextualError {
 		currentState := p.cs.Load()
 		if newState.v1Cert != nil {
 			if currentState.v1Cert == nil {
-				//adding certs is fine, actually. Networks-in-common confirmed in newCertState().
+				return util.NewContextualError("v1 certificate was added, restart required", nil, err)
-			} else {
+			}
+
 			// did IP in cert change? if so, don't set
 			if !slices.Equal(currentState.v1Cert.Networks(), newState.v1Cert.Networks()) {
 				return util.NewContextualError(
 					"Networks in new cert was different from old",
-						m{"new_networks": newState.v1Cert.Networks(), "old_networks": currentState.v1Cert.Networks(), "cert_version": cert.Version1},
+					m{"new_networks": newState.v1Cert.Networks(), "old_networks": currentState.v1Cert.Networks()},
 					nil,
 				)
 			}
 
 			if currentState.v1Cert.Curve() != newState.v1Cert.Curve() {
 				return util.NewContextualError(
-						"Curve in new v1 cert was different from old",
+					"Curve in new cert was different from old",
-						m{"new_curve": newState.v1Cert.Curve(), "old_curve": currentState.v1Cert.Curve(), "cert_version": cert.Version1},
+					m{"new_curve": newState.v1Cert.Curve(), "old_curve": currentState.v1Cert.Curve()},
 					nil,
 				)
 			}
-			}
+
+		} else if currentState.v1Cert != nil {
+			//TODO: CERT-V2 we should be able to tear this down
+			return util.NewContextualError("v1 certificate was removed, restart required", nil, err)
 		}
 
 		if newState.v2Cert != nil {
 			if currentState.v2Cert == nil {
-				//adding certs is fine, actually
+				return util.NewContextualError("v2 certificate was added, restart required", nil, err)
-			} else {
+			}
+
 			// did IP in cert change? if so, don't set
 			if !slices.Equal(currentState.v2Cert.Networks(), newState.v2Cert.Networks()) {
 				return util.NewContextualError(
 					"Networks in new cert was different from old",
-						m{"new_networks": newState.v2Cert.Networks(), "old_networks": currentState.v2Cert.Networks(), "cert_version": cert.Version2},
+					m{"new_networks": newState.v2Cert.Networks(), "old_networks": currentState.v2Cert.Networks()},
 					nil,
 				)
 			}
@@ -137,25 +142,13 @@ func (p *PKI) reloadCerts(c *config.C, initial bool) *util.ContextualError {
 			if currentState.v2Cert.Curve() != newState.v2Cert.Curve() {
 				return util.NewContextualError(
 					"Curve in new cert was different from old",
-						m{"new_curve": newState.v2Cert.Curve(), "old_curve": currentState.v2Cert.Curve(), "cert_version": cert.Version2},
+					m{"new_curve": newState.v2Cert.Curve(), "old_curve": currentState.v2Cert.Curve()},
 					nil,
 				)
 			}
-			}
 
 		} else if currentState.v2Cert != nil {
-			//newState.v1Cert is non-nil bc empty certstates aren't permitted
+			return util.NewContextualError("v2 certificate was removed, restart required", nil, err)
-			if newState.v1Cert == nil {
-				return util.NewContextualError("v1 and v2 certs are nil, this should be impossible", nil, err)
-			}
-			//if we're going to v1-only, we need to make sure we didn't orphan any v2-cert vpnaddrs
-			if !slices.Equal(currentState.v2Cert.Networks(), newState.v1Cert.Networks()) {
-				return util.NewContextualError(
-					"Removing a V2 cert is not permitted unless it has identical networks to the new V1 cert",
-					m{"new_v1_networks": newState.v1Cert.Networks(), "old_v2_networks": currentState.v2Cert.Networks()},
-					nil,
-				)
-			}
 		}
 
 		// Cipher cant be hot swapped so just leave it at what it was before

udp/conn.go

@@ -22,18 +22,6 @@ type Conn interface {
 	Close() error
 }
 
-// Datagram represents a UDP payload destined to a specific address.
-type Datagram struct {
-	Payload []byte
-	Addr    netip.AddrPort
-}
-
-// BatchConn can send multiple datagrams in one syscall.
-type BatchConn interface {
-	Conn
-	WriteBatch(pkts []Datagram) error
-}
-
 type NoopConn struct{}
 
 func (NoopConn) Rebind() error {

udp/udp_linux.go

@@ -310,51 +310,31 @@ func (u *StdConn) Close() error {
 }
 
 func NewUDPStatsEmitter(udpConns []Conn) func() {
-	if len(udpConns) == 0 {
+	// Check if our kernel supports SO_MEMINFO before registering the gauges
-		return func() {}
+	var udpGauges [][unix.SK_MEMINFO_VARS]metrics.Gauge
-	}
-
-	type statsProvider struct {
-		index int
-		conn  *StdConn
-	}
-
-	providers := make([]statsProvider, 0, len(udpConns))
-	for i, c := range udpConns {
-		if sc, ok := c.(*StdConn); ok {
-			providers = append(providers, statsProvider{index: i, conn: sc})
-		}
-	}
-
-	if len(providers) == 0 {
-		return func() {}
-	}
-
 	var meminfo [unix.SK_MEMINFO_VARS]uint32
-	if err := providers[0].conn.getMemInfo(&meminfo); err != nil {
+	if err := udpConns[0].(*StdConn).getMemInfo(&meminfo); err == nil {
-		return func() {}
+		udpGauges = make([][unix.SK_MEMINFO_VARS]metrics.Gauge, len(udpConns))
-	}
+		for i := range udpConns {
-
-	udpGauges := make([][unix.SK_MEMINFO_VARS]metrics.Gauge, len(providers))
-	for i, provider := range providers {
 			udpGauges[i] = [unix.SK_MEMINFO_VARS]metrics.Gauge{
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rmem_alloc", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rmem_alloc", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rcvbuf", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rcvbuf", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_alloc", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_alloc", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.sndbuf", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.sndbuf", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.fwd_alloc", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.fwd_alloc", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_queued", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_queued", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.optmem", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.optmem", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.backlog", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.backlog", i), nil),
-			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.drops", provider.index), nil),
+				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.drops", i), nil),
+			}
 		}
 	}
 
 	return func() {
-		for i, provider := range providers {
+		for i, gauges := range udpGauges {
-			if err := provider.conn.getMemInfo(&meminfo); err == nil {
+			if err := udpConns[i].(*StdConn).getMemInfo(&meminfo); err == nil {
 				for j := 0; j < unix.SK_MEMINFO_VARS; j++ {
-					udpGauges[i][j].Update(int64(meminfo[j]))
+					gauges[j].Update(int64(meminfo[j]))
 				}
 			}
 		}

udp/wireguard_conn_linux.go

@@ -1,225 +0,0 @@
-//go:build linux && !android && !e2e_testing
-
-package udp
-
-import (
-	"errors"
-	"net"
-	"net/netip"
-	"sync"
-	"sync/atomic"
-
-	"github.com/sirupsen/logrus"
-	"github.com/slackhq/nebula/config"
-	wgconn "github.com/slackhq/nebula/wgstack/conn"
-)
-
-// WGConn adapts WireGuard's batched UDP bind implementation to Nebula's udp.Conn interface.
-type WGConn struct {
-	l         *logrus.Logger
-	bind      *wgconn.StdNetBind
-	recvers   []wgconn.ReceiveFunc
-	batch     int
-	reqBatch  int
-	localIP   netip.Addr
-	localPort uint16
-	enableGSO bool
-	enableGRO bool
-	gsoMaxSeg int
-	closed    atomic.Bool
-
-	closeOnce sync.Once
-}
-
-// NewWireguardListener creates a UDP listener backed by WireGuard's StdNetBind.
-func NewWireguardListener(l *logrus.Logger, ip netip.Addr, port int, multi bool, batch int) (Conn, error) {
-	bind := wgconn.NewStdNetBindForAddr(ip, multi)
-	recvers, actualPort, err := bind.Open(uint16(port))
-	if err != nil {
-		return nil, err
-	}
-	if batch <= 0 {
-		batch = bind.BatchSize()
-	} else if batch > bind.BatchSize() {
-		batch = bind.BatchSize()
-	}
-	return &WGConn{
-		l:         l,
-		bind:      bind,
-		recvers:   recvers,
-		batch:     batch,
-		reqBatch:  batch,
-		localIP:   ip,
-		localPort: actualPort,
-	}, nil
-}
-
-func (c *WGConn) Rebind() error {
-	// WireGuard's bind does not support rebinding in place.
-	return nil
-}
-
-func (c *WGConn) LocalAddr() (netip.AddrPort, error) {
-	if !c.localIP.IsValid() || c.localIP.IsUnspecified() {
-		// Fallback to wildcard IPv4 for display purposes.
-		return netip.AddrPortFrom(netip.IPv4Unspecified(), c.localPort), nil
-	}
-	return netip.AddrPortFrom(c.localIP, c.localPort), nil
-}
-
-func (c *WGConn) listen(fn wgconn.ReceiveFunc, r EncReader) {
-	batchSize := c.batch
-	packets := make([][]byte, batchSize)
-	for i := range packets {
-		packets[i] = make([]byte, MTU)
-	}
-	sizes := make([]int, batchSize)
-	endpoints := make([]wgconn.Endpoint, batchSize)
-
-	for {
-		if c.closed.Load() {
-			return
-		}
-		n, err := fn(packets, sizes, endpoints)
-		if err != nil {
-			if errors.Is(err, net.ErrClosed) {
-				return
-			}
-			if c.l != nil {
-				c.l.WithError(err).Debug("wireguard UDP listener receive error")
-			}
-			continue
-		}
-		for i := 0; i < n; i++ {
-			if sizes[i] == 0 {
-				continue
-			}
-			stdEp, ok := endpoints[i].(*wgconn.StdNetEndpoint)
-			if !ok {
-				if c.l != nil {
-					c.l.Warn("wireguard UDP listener received unexpected endpoint type")
-				}
-				continue
-			}
-			addr := stdEp.AddrPort
-			r(addr, packets[i][:sizes[i]])
-			endpoints[i] = nil
-		}
-	}
-}
-
-func (c *WGConn) ListenOut(r EncReader) {
-	for _, fn := range c.recvers {
-		go c.listen(fn, r)
-	}
-}
-
-func (c *WGConn) WriteTo(b []byte, addr netip.AddrPort) error {
-	if len(b) == 0 {
-		return nil
-	}
-	if c.closed.Load() {
-		return net.ErrClosed
-	}
-	ep := &wgconn.StdNetEndpoint{AddrPort: addr}
-	return c.bind.Send([][]byte{b}, ep)
-}
-
-func (c *WGConn) WriteBatch(datagrams []Datagram) error {
-	if len(datagrams) == 0 {
-		return nil
-	}
-	if c.closed.Load() {
-		return net.ErrClosed
-	}
-	max := c.batch
-	if max <= 0 {
-		max = len(datagrams)
-		if max == 0 {
-			max = 1
-		}
-	}
-	bufs := make([][]byte, 0, max)
-	var (
-		current  netip.AddrPort
-		endpoint *wgconn.StdNetEndpoint
-		haveAddr bool
-	)
-	flush := func() error {
-		if len(bufs) == 0 || endpoint == nil {
-			bufs = bufs[:0]
-			return nil
-		}
-		err := c.bind.Send(bufs, endpoint)
-		bufs = bufs[:0]
-		return err
-	}
-
-	for _, d := range datagrams {
-		if len(d.Payload) == 0 || !d.Addr.IsValid() {
-			continue
-		}
-		if !haveAddr || d.Addr != current {
-			if err := flush(); err != nil {
-				return err
-			}
-			current = d.Addr
-			endpoint = &wgconn.StdNetEndpoint{AddrPort: current}
-			haveAddr = true
-		}
-		bufs = append(bufs, d.Payload)
-		if len(bufs) >= max {
-			if err := flush(); err != nil {
-				return err
-			}
-		}
-	}
-	return flush()
-}
-
-func (c *WGConn) ConfigureOffload(enableGSO, enableGRO bool, maxSegments int) {
-	c.enableGSO = enableGSO
-	c.enableGRO = enableGRO
-	if maxSegments <= 0 {
-		maxSegments = 1
-	} else if maxSegments > wgconn.IdealBatchSize {
-		maxSegments = wgconn.IdealBatchSize
-	}
-	c.gsoMaxSeg = maxSegments
-
-	effectiveBatch := c.reqBatch
-	if enableGSO && c.bind != nil {
-		bindBatch := c.bind.BatchSize()
-		if effectiveBatch < bindBatch {
-			if c.l != nil {
-				c.l.WithFields(logrus.Fields{
-					"requested": c.reqBatch,
-					"effective": bindBatch,
-				}).Warn("listen.batch below wireguard minimum; using bind batch size for UDP GSO support")
-			}
-			effectiveBatch = bindBatch
-		}
-	}
-	c.batch = effectiveBatch
-
-	if c.l != nil {
-		c.l.WithFields(logrus.Fields{
-			"enableGSO":      enableGSO,
-			"enableGRO":      enableGRO,
-			"gsoMaxSegments": maxSegments,
-		}).Debug("configured wireguard UDP offload")
-	}
-}
-
-func (c *WGConn) ReloadConfig(*config.C) {
-	// WireGuard bind currently does not expose runtime configuration knobs.
-}
-
-func (c *WGConn) Close() error {
-	var err error
-	c.closeOnce.Do(func() {
-		c.closed.Store(true)
-		err = c.bind.Close()
-	})
-	return err
-}

udp/wireguard_conn_unsupported.go

@@ -1,15 +0,0 @@
-//go:build !linux || android || e2e_testing
-
-package udp
-
-import (
-	"fmt"
-	"net/netip"
-
-	"github.com/sirupsen/logrus"
-)
-
-// NewWireguardListener is only available on Linux builds.
-func NewWireguardListener(*logrus.Logger, netip.Addr, int, bool, int) (Conn, error) {
-	return nil, fmt.Errorf("wireguard experimental UDP listener is only supported on Linux")
-}

wgstack/conn/bind_std.go

@@ -1,539 +0,0 @@
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package conn
-
-import (
-	"context"
-	"errors"
-	"net"
-	"net/netip"
-	"runtime"
-	"strconv"
-	"sync"
-	"syscall"
-
-	"golang.org/x/net/ipv4"
-	"golang.org/x/net/ipv6"
-	"golang.org/x/sys/unix"
-)
-
-var (
-	_ Bind = (*StdNetBind)(nil)
-)
-
-// StdNetBind implements Bind for all platforms. While Windows has its own Bind
-// (see bind_windows.go), it may fall back to StdNetBind.
-// TODO: Remove usage of ipv{4,6}.PacketConn when net.UDPConn has comparable
-// methods for sending and receiving multiple datagrams per-syscall. See the
-// proposal in https://github.com/golang/go/issues/45886#issuecomment-1218301564.
-type StdNetBind struct {
-	mu     sync.Mutex // protects all fields except as specified
-	ipv4   *net.UDPConn
-	ipv6   *net.UDPConn
-	ipv4PC *ipv4.PacketConn // will be nil on non-Linux
-	ipv6PC *ipv6.PacketConn // will be nil on non-Linux
-
-	// these three fields are not guarded by mu
-	udpAddrPool  sync.Pool
-	ipv4MsgsPool sync.Pool
-	ipv6MsgsPool sync.Pool
-
-	blackhole4 bool
-	blackhole6 bool
-
-	listenAddr4 string
-	listenAddr6 string
-	bindV4      bool
-	bindV6      bool
-	reusePort   bool
-}
-
-func newStdNetBind() *StdNetBind {
-	return &StdNetBind{
-		udpAddrPool: sync.Pool{
-			New: func() any {
-				return &net.UDPAddr{
-					IP: make([]byte, 16),
-				}
-			},
-		},
-
-		ipv4MsgsPool: sync.Pool{
-			New: func() any {
-				msgs := make([]ipv4.Message, IdealBatchSize)
-				for i := range msgs {
-					msgs[i].Buffers = make(net.Buffers, 1)
-					msgs[i].OOB = make([]byte, srcControlSize)
-				}
-				return &msgs
-			},
-		},
-
-		ipv6MsgsPool: sync.Pool{
-			New: func() any {
-				msgs := make([]ipv6.Message, IdealBatchSize)
-				for i := range msgs {
-					msgs[i].Buffers = make(net.Buffers, 1)
-					msgs[i].OOB = make([]byte, srcControlSize)
-				}
-				return &msgs
-			},
-		},
-		bindV4:    true,
-		bindV6:    true,
-		reusePort: false,
-	}
-}
-
-// NewStdNetBind creates a bind that listens on all interfaces.
-func NewStdNetBind() *StdNetBind {
-	return newStdNetBind()
-}
-
-// NewStdNetBindForAddr creates a bind that listens on a specific address.
-// If addr is IPv4, only the IPv4 socket will be created. For IPv6, only the
-// IPv6 socket will be created.
-func NewStdNetBindForAddr(addr netip.Addr, reusePort bool) *StdNetBind {
-	b := newStdNetBind()
-	if addr.IsValid() {
-		if addr.IsUnspecified() {
-			// keep dual-stack defaults with empty listen addresses
-		} else if addr.Is4() {
-			b.listenAddr4 = addr.Unmap().String()
-			b.bindV4 = true
-			b.bindV6 = false
-		} else {
-			b.listenAddr6 = addr.Unmap().String()
-			b.bindV6 = true
-			b.bindV4 = false
-		}
-	}
-	b.reusePort = reusePort
-	return b
-}
-
-type StdNetEndpoint struct {
-	// AddrPort is the endpoint destination.
-	netip.AddrPort
-	// src is the current sticky source address and interface index, if supported.
-	src struct {
-		netip.Addr
-		ifidx int32
-	}
-}
-
-var (
-	_ Bind     = (*StdNetBind)(nil)
-	_ Endpoint = &StdNetEndpoint{}
-)
-
-func (*StdNetBind) ParseEndpoint(s string) (Endpoint, error) {
-	e, err := netip.ParseAddrPort(s)
-	if err != nil {
-		return nil, err
-	}
-	return &StdNetEndpoint{
-		AddrPort: e,
-	}, nil
-}
-
-func (e *StdNetEndpoint) ClearSrc() {
-	e.src.ifidx = 0
-	e.src.Addr = netip.Addr{}
-}
-
-func (e *StdNetEndpoint) DstIP() netip.Addr {
-	return e.AddrPort.Addr()
-}
-
-func (e *StdNetEndpoint) SrcIP() netip.Addr {
-	return e.src.Addr
-}
-
-func (e *StdNetEndpoint) SrcIfidx() int32 {
-	return e.src.ifidx
-}
-
-func (e *StdNetEndpoint) DstToBytes() []byte {
-	b, _ := e.AddrPort.MarshalBinary()
-	return b
-}
-
-func (e *StdNetEndpoint) DstToString() string {
-	return e.AddrPort.String()
-}
-
-func (e *StdNetEndpoint) SrcToString() string {
-	return e.src.Addr.String()
-}
-
-func (s *StdNetBind) listenNet(network string, host string, port int) (*net.UDPConn, int, error) {
-	lc := listenConfig()
-	if s.reusePort {
-		base := lc.Control
-		lc.Control = func(network, address string, c syscall.RawConn) error {
-			if base != nil {
-				if err := base(network, address, c); err != nil {
-					return err
-				}
-			}
-			return c.Control(func(fd uintptr) {
-				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
-			})
-		}
-	}
-
-	addr := ":" + strconv.Itoa(port)
-	if host != "" {
-		addr = net.JoinHostPort(host, strconv.Itoa(port))
-	}
-
-	conn, err := lc.ListenPacket(context.Background(), network, addr)
-	if err != nil {
-		return nil, 0, err
-	}
-
-	// Retrieve port.
-	laddr := conn.LocalAddr()
-	uaddr, err := net.ResolveUDPAddr(
-		laddr.Network(),
-		laddr.String(),
-	)
-	if err != nil {
-		return nil, 0, err
-	}
-	return conn.(*net.UDPConn), uaddr.Port, nil
-}
-
-func (s *StdNetBind) openIPv4(port int) (*net.UDPConn, *ipv4.PacketConn, int, error) {
-	if !s.bindV4 {
-		return nil, nil, port, nil
-	}
-	host := s.listenAddr4
-	conn, actualPort, err := s.listenNet("udp4", host, port)
-	if err != nil {
-		if errors.Is(err, syscall.EAFNOSUPPORT) {
-			return nil, nil, port, nil
-		}
-		return nil, nil, port, err
-	}
-	if runtime.GOOS != "linux" {
-		return conn, nil, actualPort, nil
-	}
-	pc := ipv4.NewPacketConn(conn)
-	return conn, pc, actualPort, nil
-}
-
-func (s *StdNetBind) openIPv6(port int) (*net.UDPConn, *ipv6.PacketConn, int, error) {
-	if !s.bindV6 {
-		return nil, nil, port, nil
-	}
-	host := s.listenAddr6
-	conn, actualPort, err := s.listenNet("udp6", host, port)
-	if err != nil {
-		if errors.Is(err, syscall.EAFNOSUPPORT) {
-			return nil, nil, port, nil
-		}
-		return nil, nil, port, err
-	}
-	if runtime.GOOS != "linux" {
-		return conn, nil, actualPort, nil
-	}
-	pc := ipv6.NewPacketConn(conn)
-	return conn, pc, actualPort, nil
-}
-
-func (s *StdNetBind) Open(uport uint16) ([]ReceiveFunc, uint16, error) {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	var err error
-	var tries int
-
-	if s.ipv4 != nil || s.ipv6 != nil {
-		return nil, 0, ErrBindAlreadyOpen
-	}
-
-	// Attempt to open ipv4 and ipv6 listeners on the same port.
-	// If uport is 0, we can retry on failure.
-again:
-	port := int(uport)
-	var v4conn *net.UDPConn
-	var v6conn *net.UDPConn
-	var v4pc *ipv4.PacketConn
-	var v6pc *ipv6.PacketConn
-
-	v4conn, v4pc, port, err = s.openIPv4(port)
-	if err != nil {
-		return nil, 0, err
-	}
-
-	// Listen on the same port as we're using for ipv4.
-	v6conn, v6pc, port, err = s.openIPv6(port)
-	if uport == 0 && errors.Is(err, syscall.EADDRINUSE) && tries < 100 {
-		if v4conn != nil {
-			v4conn.Close()
-		}
-		tries++
-		goto again
-	}
-	if err != nil {
-		if v4conn != nil {
-			v4conn.Close()
-		}
-		return nil, 0, err
-	}
-
-	var fns []ReceiveFunc
-	if v4conn != nil {
-		s.ipv4 = v4conn
-		if v4pc != nil {
-			s.ipv4PC = v4pc
-		}
-		fns = append(fns, s.makeReceiveIPv4(v4pc, v4conn))
-	}
-	if v6conn != nil {
-		s.ipv6 = v6conn
-		if v6pc != nil {
-			s.ipv6PC = v6pc
-		}
-		fns = append(fns, s.makeReceiveIPv6(v6pc, v6conn))
-	}
-	if len(fns) == 0 {
-		return nil, 0, syscall.EAFNOSUPPORT
-	}
-
-	return fns, uint16(port), nil
-}
-
-func (s *StdNetBind) makeReceiveIPv4(pc *ipv4.PacketConn, conn *net.UDPConn) ReceiveFunc {
-	return func(bufs [][]byte, sizes []int, eps []Endpoint) (n int, err error) {
-		msgs := s.ipv4MsgsPool.Get().(*[]ipv4.Message)
-		defer s.ipv4MsgsPool.Put(msgs)
-		for i := range bufs {
-			(*msgs)[i].Buffers[0] = bufs[i]
-		}
-		var numMsgs int
-		if runtime.GOOS == "linux" && pc != nil {
-			numMsgs, err = pc.ReadBatch(*msgs, 0)
-			if err != nil {
-				return 0, err
-			}
-		} else {
-			msg := &(*msgs)[0]
-			msg.N, msg.NN, _, msg.Addr, err = conn.ReadMsgUDP(msg.Buffers[0], msg.OOB)
-			if err != nil {
-				return 0, err
-			}
-			numMsgs = 1
-		}
-		for i := 0; i < numMsgs; i++ {
-			msg := &(*msgs)[i]
-			sizes[i] = msg.N
-			addrPort := msg.Addr.(*net.UDPAddr).AddrPort()
-			ep := &StdNetEndpoint{AddrPort: addrPort} // TODO: remove allocation
-			getSrcFromControl(msg.OOB[:msg.NN], ep)
-			eps[i] = ep
-		}
-		return numMsgs, nil
-	}
-}
-
-func (s *StdNetBind) makeReceiveIPv6(pc *ipv6.PacketConn, conn *net.UDPConn) ReceiveFunc {
-	return func(bufs [][]byte, sizes []int, eps []Endpoint) (n int, err error) {
-		msgs := s.ipv6MsgsPool.Get().(*[]ipv6.Message)
-		defer s.ipv6MsgsPool.Put(msgs)
-		for i := range bufs {
-			(*msgs)[i].Buffers[0] = bufs[i]
-		}
-		var numMsgs int
-		if runtime.GOOS == "linux" && pc != nil {
-			numMsgs, err = pc.ReadBatch(*msgs, 0)
-			if err != nil {
-				return 0, err
-			}
-		} else {
-			msg := &(*msgs)[0]
-			msg.N, msg.NN, _, msg.Addr, err = conn.ReadMsgUDP(msg.Buffers[0], msg.OOB)
-			if err != nil {
-				return 0, err
-			}
-			numMsgs = 1
-		}
-		for i := 0; i < numMsgs; i++ {
-			msg := &(*msgs)[i]
-			sizes[i] = msg.N
-			addrPort := msg.Addr.(*net.UDPAddr).AddrPort()
-			ep := &StdNetEndpoint{AddrPort: addrPort} // TODO: remove allocation
-			getSrcFromControl(msg.OOB[:msg.NN], ep)
-			eps[i] = ep
-		}
-		return numMsgs, nil
-	}
-}
-
-// TODO: When all Binds handle IdealBatchSize, remove this dynamic function and
-// rename the IdealBatchSize constant to BatchSize.
-func (s *StdNetBind) BatchSize() int {
-	if runtime.GOOS == "linux" {
-		return IdealBatchSize
-	}
-	return 1
-}
-
-func (s *StdNetBind) Close() error {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	var err1, err2 error
-	if s.ipv4 != nil {
-		err1 = s.ipv4.Close()
-		s.ipv4 = nil
-		s.ipv4PC = nil
-	}
-	if s.ipv6 != nil {
-		err2 = s.ipv6.Close()
-		s.ipv6 = nil
-		s.ipv6PC = nil
-	}
-	s.blackhole4 = false
-	s.blackhole6 = false
-	if err1 != nil {
-		return err1
-	}
-	return err2
-}
-
-func (s *StdNetBind) Send(bufs [][]byte, endpoint Endpoint) error {
-	s.mu.Lock()
-	blackhole := s.blackhole4
-	conn := s.ipv4
-	var (
-		pc4 *ipv4.PacketConn
-		pc6 *ipv6.PacketConn
-	)
-	is6 := false
-	if endpoint.DstIP().Is6() {
-		blackhole = s.blackhole6
-		conn = s.ipv6
-		pc6 = s.ipv6PC
-		is6 = true
-	} else {
-		pc4 = s.ipv4PC
-	}
-	s.mu.Unlock()
-
-	if blackhole {
-		return nil
-	}
-	if conn == nil {
-		return syscall.EAFNOSUPPORT
-	}
-	if is6 {
-		return s.send6(conn, pc6, endpoint, bufs)
-	} else {
-		return s.send4(conn, pc4, endpoint, bufs)
-	}
-}
-
-func (s *StdNetBind) send4(conn *net.UDPConn, pc *ipv4.PacketConn, ep Endpoint, bufs [][]byte) error {
-	ua := s.udpAddrPool.Get().(*net.UDPAddr)
-	as4 := ep.DstIP().As4()
-	copy(ua.IP, as4[:])
-	ua.IP = ua.IP[:4]
-	ua.Port = int(ep.(*StdNetEndpoint).Port())
-	msgs := s.ipv4MsgsPool.Get().(*[]ipv4.Message)
-	for i, buf := range bufs {
-		(*msgs)[i].Buffers[0] = buf
-		(*msgs)[i].Addr = ua
-		setSrcControl(&(*msgs)[i].OOB, ep.(*StdNetEndpoint))
-	}
-	var (
-		n     int
-		err   error
-		start int
-	)
-	if runtime.GOOS == "linux" && pc != nil {
-		for {
-			n, err = pc.WriteBatch((*msgs)[start:len(bufs)], 0)
-			if err != nil {
-				if errors.Is(err, syscall.EAFNOSUPPORT) {
-					for j := start; j < len(bufs); j++ {
-						_, _, werr := conn.WriteMsgUDP(bufs[j], (*msgs)[j].OOB, ua)
-						if werr != nil {
-							err = werr
-							break
-						}
-					}
-				}
-				break
-			}
-			if n == len((*msgs)[start:len(bufs)]) {
-				break
-			}
-			start += n
-		}
-	} else {
-		for i, buf := range bufs {
-			_, _, err = conn.WriteMsgUDP(buf, (*msgs)[i].OOB, ua)
-			if err != nil {
-				break
-			}
-		}
-	}
-	s.udpAddrPool.Put(ua)
-	s.ipv4MsgsPool.Put(msgs)
-	return err
-}
-
-func (s *StdNetBind) send6(conn *net.UDPConn, pc *ipv6.PacketConn, ep Endpoint, bufs [][]byte) error {
-	ua := s.udpAddrPool.Get().(*net.UDPAddr)
-	as16 := ep.DstIP().As16()
-	copy(ua.IP, as16[:])
-	ua.IP = ua.IP[:16]
-	ua.Port = int(ep.(*StdNetEndpoint).Port())
-	msgs := s.ipv6MsgsPool.Get().(*[]ipv6.Message)
-	for i, buf := range bufs {
-		(*msgs)[i].Buffers[0] = buf
-		(*msgs)[i].Addr = ua
-		setSrcControl(&(*msgs)[i].OOB, ep.(*StdNetEndpoint))
-	}
-	var (
-		n     int
-		err   error
-		start int
-	)
-	if runtime.GOOS == "linux" && pc != nil {
-		for {
-			n, err = pc.WriteBatch((*msgs)[start:len(bufs)], 0)
-			if err != nil {
-				if errors.Is(err, syscall.EAFNOSUPPORT) {
-					for j := start; j < len(bufs); j++ {
-						_, _, werr := conn.WriteMsgUDP(bufs[j], (*msgs)[j].OOB, ua)
-						if werr != nil {
-							err = werr
-							break
-						}
-					}
-				}
-				break
-			}
-			if n == len((*msgs)[start:len(bufs)]) {
-				break
-			}
-			start += n
-		}
-	} else {
-		for i, buf := range bufs {
-			_, _, err = conn.WriteMsgUDP(buf, (*msgs)[i].OOB, ua)
-			if err != nil {
-				break
-			}
-		}
-	}
-	s.udpAddrPool.Put(ua)
-	s.ipv6MsgsPool.Put(msgs)
-	return err
-}

wgstack/conn/conn.go

@@ -1,131 +0,0 @@
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package conn
-
-import (
-	"errors"
-	"fmt"
-	"net/netip"
-	"reflect"
-	"runtime"
-	"strings"
-)
-
-const (
-	IdealBatchSize = 128 // maximum number of packets handled per read and write
-)
-
-// A ReceiveFunc receives at least one packet from the network and writes them
-// into packets. On a successful read it returns the number of elements of
-// sizes, packets, and endpoints that should be evaluated. Some elements of
-// sizes may be zero, and callers should ignore them. Callers must pass a sizes
-// and eps slice with a length greater than or equal to the length of packets.
-// These lengths must not exceed the length of the associated Bind.BatchSize().
-type ReceiveFunc func(packets [][]byte, sizes []int, eps []Endpoint) (n int, err error)
-
-// A Bind listens on a port for both IPv6 and IPv4 UDP traffic.
-//
-// A Bind interface may also be a PeekLookAtSocketFd or BindSocketToInterface,
-// depending on the platform-specific implementation.
-type Bind interface {
-	// Open puts the Bind into a listening state on a given port and reports the actual
-	// port that it bound to. Passing zero results in a random selection.
-	// fns is the set of functions that will be called to receive packets.
-	Open(port uint16) (fns []ReceiveFunc, actualPort uint16, err error)
-
-	// Close closes the Bind listener.
-	// All fns returned by Open must return net.ErrClosed after a call to Close.
-	Close() error
-
-	// SetMark sets the mark for each packet sent through this Bind.
-	// This mark is passed to the kernel as the socket option SO_MARK.
-	SetMark(mark uint32) error
-
-	// Send writes one or more packets in bufs to address ep. The length of
-	// bufs must not exceed BatchSize().
-	Send(bufs [][]byte, ep Endpoint) error
-
-	// ParseEndpoint creates a new endpoint from a string.
-	ParseEndpoint(s string) (Endpoint, error)
-
-	// BatchSize is the number of buffers expected to be passed to
-	// the ReceiveFuncs, and the maximum expected to be passed to SendBatch.
-	BatchSize() int
-}
-
-// BindSocketToInterface is implemented by Bind objects that support being
-// tied to a single network interface. Used by wireguard-windows.
-type BindSocketToInterface interface {
-	BindSocketToInterface4(interfaceIndex uint32, blackhole bool) error
-	BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error
-}
-
-// PeekLookAtSocketFd is implemented by Bind objects that support having their
-// file descriptor peeked at. Used by wireguard-android.
-type PeekLookAtSocketFd interface {
-	PeekLookAtSocketFd4() (fd int, err error)
-	PeekLookAtSocketFd6() (fd int, err error)
-}
-
-// An Endpoint maintains the source/destination caching for a peer.
-//
-//	dst: the remote address of a peer ("endpoint" in uapi terminology)
-//	src: the local address from which datagrams originate going to the peer
-type Endpoint interface {
-	ClearSrc()           // clears the source address
-	SrcToString() string // returns the local source address (ip:port)
-	DstToString() string // returns the destination address (ip:port)
-	DstToBytes() []byte  // used for mac2 cookie calculations
-	DstIP() netip.Addr
-	SrcIP() netip.Addr
-}
-
-var (
-	ErrBindAlreadyOpen   = errors.New("bind is already open")
-	ErrWrongEndpointType = errors.New("endpoint type does not correspond with bind type")
-)
-
-func (fn ReceiveFunc) PrettyName() string {
-	name := runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
-	// 0. cheese/taco.beansIPv6.func12.func21218-fm
-	name = strings.TrimSuffix(name, "-fm")
-	// 1. cheese/taco.beansIPv6.func12.func21218
-	if idx := strings.LastIndexByte(name, '/'); idx != -1 {
-		name = name[idx+1:]
-		// 2. taco.beansIPv6.func12.func21218
-	}
-	for {
-		var idx int
-		for idx = len(name) - 1; idx >= 0; idx-- {
-			if name[idx] < '0' || name[idx] > '9' {
-				break
-			}
-		}
-		if idx == len(name)-1 {
-			break
-		}
-		const dotFunc = ".func"
-		if !strings.HasSuffix(name[:idx+1], dotFunc) {
-			break
-		}
-		name = name[:idx+1-len(dotFunc)]
-		// 3. taco.beansIPv6.func12
-		// 4. taco.beansIPv6
-	}
-	if idx := strings.LastIndexByte(name, '.'); idx != -1 {
-		name = name[idx+1:]
-		// 5. beansIPv6
-	}
-	if name == "" {
-		return fmt.Sprintf("%p", fn)
-	}
-	if strings.HasSuffix(name, "IPv4") {
-		return "v4"
-	}
-	if strings.HasSuffix(name, "IPv6") {
-		return "v6"
-	}
-	return name
-}

wgstack/conn/controlfns.go

@@ -1,42 +0,0 @@
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package conn
-
-import (
-	"net"
-	"syscall"
-)
-
-// UDP socket read/write buffer size (7MB). The value of 7MB is chosen as it is
-// the max supported by a default configuration of macOS. Some platforms will
-// silently clamp the value to other maximums, such as linux clamping to
-// net.core.{r,w}mem_max (see _linux.go for additional implementation that works
-// around this limitation)
-const socketBufferSize = 7 << 20
-
-// controlFn is the callback function signature from net.ListenConfig.Control.
-// It is used to apply platform specific configuration to the socket prior to
-// bind.
-type controlFn func(network, address string, c syscall.RawConn) error
-
-// controlFns is a list of functions that are called from the listen config
-// that can apply socket options.
-var controlFns = []controlFn{}
-
-// listenConfig returns a net.ListenConfig that applies the controlFns to the
-// socket prior to bind. This is used to apply socket buffer sizing and packet
-// information OOB configuration for sticky sockets.
-func listenConfig() *net.ListenConfig {
-	return &net.ListenConfig{
-		Control: func(network, address string, c syscall.RawConn) error {
-			for _, fn := range controlFns {
-				if err := fn(network, address, c); err != nil {
-					return err
-				}
-			}
-			return nil
-		},
-	}
-}

wgstack/conn/controlfns_linux.go

@@ -1,62 +0,0 @@
-//go:build linux
-
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package conn
-
-import (
-	"fmt"
-	"runtime"
-	"syscall"
-
-	"golang.org/x/sys/unix"
-)
-
-func init() {
-	controlFns = append(controlFns,
-
-		// Attempt to set the socket buffer size beyond net.core.{r,w}mem_max by
-		// using SO_*BUFFORCE. This requires CAP_NET_ADMIN, and is allowed here to
-		// fail silently - the result of failure is lower performance on very fast
-		// links or high latency links.
-		func(network, address string, c syscall.RawConn) error {
-			return c.Control(func(fd uintptr) {
-				// Set up to *mem_max
-				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_RCVBUF, socketBufferSize)
-				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_SNDBUF, socketBufferSize)
-				// Set beyond *mem_max if CAP_NET_ADMIN
-				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_RCVBUFFORCE, socketBufferSize)
-				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_SNDBUFFORCE, socketBufferSize)
-			})
-		},
-
-		// Enable receiving of the packet information (IP_PKTINFO for IPv4,
-		// IPV6_PKTINFO for IPv6) that is used to implement sticky socket support.
-		func(network, address string, c syscall.RawConn) error {
-			var err error
-			switch network {
-			case "udp4":
-				if runtime.GOOS != "android" {
-					c.Control(func(fd uintptr) {
-						err = unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_PKTINFO, 1)
-					})
-				}
-			case "udp6":
-				c.Control(func(fd uintptr) {
-					if runtime.GOOS != "android" {
-						err = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_RECVPKTINFO, 1)
-						if err != nil {
-							return
-						}
-					}
-					err = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_V6ONLY, 1)
-				})
-			default:
-				err = fmt.Errorf("unhandled network: %s: %w", network, unix.EINVAL)
-			}
-			return err
-		},
-	)
-}

wgstack/conn/default.go

@@ -1,9 +0,0 @@
-//go:build !windows
-
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package conn
-
-func NewDefaultBind() Bind { return NewStdNetBind() }

wgstack/conn/errors_default.go

@@ -1,12 +0,0 @@
-//go:build !linux
-
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
- */
-
-package conn
-
-func errShouldDisableUDPGSO(err error) bool {
-	return false
-}

wgstack/conn/errors_linux.go

@@ -1,26 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
- */
-
-package conn
-
-import (
-	"errors"
-	"os"
-
-	"golang.org/x/sys/unix"
-)
-
-func errShouldDisableUDPGSO(err error) bool {
-	var serr *os.SyscallError
-	if errors.As(err, &serr) {
-		// EIO is returned by udp_send_skb() if the device driver does not have
-		// tx checksumming enabled, which is a hard requirement of UDP_SEGMENT.
-		// See:
-		// https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man7/udp.7?id=806eabd74910447f21005160e90957bde4db0183#n228
-		// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/ipv4/udp.c?h=v6.2&id=c9c3395d5e3dcc6daee66c6908354d47bf98cb0c#n942
-		return serr.Err == unix.EIO
-	}
-	return false
-}

wgstack/conn/features_default.go

@@ -1,15 +0,0 @@
-//go:build !linux
-// +build !linux
-
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
- */
-
-package conn
-
-import "net"
-
-func supportsUDPOffload(conn *net.UDPConn) (txOffload, rxOffload bool) {
-	return
-}

wgstack/conn/features_linux.go

@@ -1,29 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
- */
-
-package conn
-
-import (
-	"net"
-
-	"golang.org/x/sys/unix"
-)
-
-func supportsUDPOffload(conn *net.UDPConn) (txOffload, rxOffload bool) {
-	rc, err := conn.SyscallConn()
-	if err != nil {
-		return
-	}
-	err = rc.Control(func(fd uintptr) {
-		_, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_SEGMENT)
-		txOffload = errSyscall == nil
-		opt, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_GRO)
-		rxOffload = errSyscall == nil && opt == 1
-	})
-	if err != nil {
-		return false, false
-	}
-	return txOffload, rxOffload
-}

wgstack/conn/gso_default.go

@@ -1,21 +0,0 @@
-//go:build !linux
-
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
- */
-
-package conn
-
-// getGSOSize parses control for UDP_GRO and if found returns its GSO size data.
-func getGSOSize(control []byte) (int, error) {
-	return 0, nil
-}
-
-// setGSOSize sets a UDP_SEGMENT in control based on gsoSize.
-func setGSOSize(control *[]byte, gsoSize uint16) {
-}
-
-// gsoControlSize returns the recommended buffer size for pooling sticky and UDP
-// offloading control data.
-const gsoControlSize = 0

wgstack/conn/gso_linux.go

@@ -1,65 +0,0 @@
-//go:build linux
-
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
- */
-
-package conn
-
-import (
-	"fmt"
-	"unsafe"
-
-	"golang.org/x/sys/unix"
-)
-
-const (
-	sizeOfGSOData = 2
-)
-
-// getGSOSize parses control for UDP_GRO and if found returns its GSO size data.
-func getGSOSize(control []byte) (int, error) {
-	var (
-		hdr  unix.Cmsghdr
-		data []byte
-		rem  = control
-		err  error
-	)
-
-	for len(rem) > unix.SizeofCmsghdr {
-		hdr, data, rem, err = unix.ParseOneSocketControlMessage(rem)
-		if err != nil {
-			return 0, fmt.Errorf("error parsing socket control message: %w", err)
-		}
-		if hdr.Level == unix.SOL_UDP && hdr.Type == unix.UDP_GRO && len(data) >= sizeOfGSOData {
-			var gso uint16
-			copy(unsafe.Slice((*byte)(unsafe.Pointer(&gso)), sizeOfGSOData), data[:sizeOfGSOData])
-			return int(gso), nil
-		}
-	}
-	return 0, nil
-}
-
-// setGSOSize sets a UDP_SEGMENT in control based on gsoSize. It leaves existing
-// data in control untouched.
-func setGSOSize(control *[]byte, gsoSize uint16) {
-	existingLen := len(*control)
-	avail := cap(*control) - existingLen
-	space := unix.CmsgSpace(sizeOfGSOData)
-	if avail < space {
-		return
-	}
-	*control = (*control)[:cap(*control)]
-	gsoControl := (*control)[existingLen:]
-	hdr := (*unix.Cmsghdr)(unsafe.Pointer(&(gsoControl)[0]))
-	hdr.Level = unix.SOL_UDP
-	hdr.Type = unix.UDP_SEGMENT
-	hdr.SetLen(unix.CmsgLen(sizeOfGSOData))
-	copy((gsoControl)[unix.CmsgLen(0):], unsafe.Slice((*byte)(unsafe.Pointer(&gsoSize)), sizeOfGSOData))
-	*control = (*control)[:existingLen+space]
-}
-
-// gsoControlSize returns the recommended buffer size for pooling UDP
-// offloading control data.
-var gsoControlSize = unix.CmsgSpace(sizeOfGSOData)

wgstack/conn/mark_unix.go

@@ -1,64 +0,0 @@
-//go:build linux || openbsd || freebsd
-
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package conn
-
-import (
-	"runtime"
-
-	"golang.org/x/sys/unix"
-)
-
-var fwmarkIoctl int
-
-func init() {
-	switch runtime.GOOS {
-	case "linux", "android":
-		fwmarkIoctl = 36 /* unix.SO_MARK */
-	case "freebsd":
-		fwmarkIoctl = 0x1015 /* unix.SO_USER_COOKIE */
-	case "openbsd":
-		fwmarkIoctl = 0x1021 /* unix.SO_RTABLE */
-	}
-}
-
-func (s *StdNetBind) SetMark(mark uint32) error {
-	var operr error
-	if fwmarkIoctl == 0 {
-		return nil
-	}
-	if s.ipv4 != nil {
-		fd, err := s.ipv4.SyscallConn()
-		if err != nil {
-			return err
-		}
-		err = fd.Control(func(fd uintptr) {
-			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
-		})
-		if err == nil {
-			err = operr
-		}
-		if err != nil {
-			return err
-		}
-	}
-	if s.ipv6 != nil {
-		fd, err := s.ipv6.SyscallConn()
-		if err != nil {
-			return err
-		}
-		err = fd.Control(func(fd uintptr) {
-			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
-		})
-		if err == nil {
-			err = operr
-		}
-		if err != nil {
-			return err
-		}
-	}
-	return nil
-}

wgstack/conn/sticky_default.go

@@ -1,42 +0,0 @@
-//go:build !linux || android
-
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
- */
-
-package conn
-
-import "net/netip"
-
-func (e *StdNetEndpoint) SrcIP() netip.Addr {
-	return netip.Addr{}
-}
-
-func (e *StdNetEndpoint) SrcIfidx() int32 {
-	return 0
-}
-
-func (e *StdNetEndpoint) SrcToString() string {
-	return ""
-}
-
-// TODO: macOS, FreeBSD and other BSDs likely do support the sticky sockets
-// {get,set}srcControl feature set, but use alternatively named flags and need
-// ports and require testing.
-
-// getSrcFromControl parses the control for PKTINFO and if found updates ep with
-// the source information found.
-func getSrcFromControl(control []byte, ep *StdNetEndpoint) {
-}
-
-// setSrcControl parses the control for PKTINFO and if found updates ep with
-// the source information found.
-func setSrcControl(control *[]byte, ep *StdNetEndpoint) {
-}
-
-// stickyControlSize returns the recommended buffer size for pooling sticky
-// offloading control data.
-const stickyControlSize = 0
-
-const StdNetSupportsStickySockets = false

wgstack/conn/sticky_linux.go

@@ -1,116 +0,0 @@
-//go:build linux && !android
-
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package conn
-
-import (
-	"net/netip"
-	"unsafe"
-
-	"golang.org/x/sys/unix"
-)
-
-// getSrcFromControl parses the control for PKTINFO and if found updates ep with
-// the source information found.
-func getSrcFromControl(control []byte, ep *StdNetEndpoint) {
-	ep.ClearSrc()
-
-	var (
-		hdr  unix.Cmsghdr
-		data []byte
-		rem  []byte = control
-		err  error
-	)
-
-	for len(rem) > unix.SizeofCmsghdr {
-		hdr, data, rem, err = unix.ParseOneSocketControlMessage(rem)
-		if err != nil {
-			return
-		}
-
-		if hdr.Level == unix.IPPROTO_IP &&
-			hdr.Type == unix.IP_PKTINFO {
-
-			info := pktInfoFromBuf[unix.Inet4Pktinfo](data)
-			ep.src.Addr = netip.AddrFrom4(info.Spec_dst)
-			ep.src.ifidx = info.Ifindex
-
-			return
-		}
-
-		if hdr.Level == unix.IPPROTO_IPV6 &&
-			hdr.Type == unix.IPV6_PKTINFO {
-
-			info := pktInfoFromBuf[unix.Inet6Pktinfo](data)
-			ep.src.Addr = netip.AddrFrom16(info.Addr)
-			ep.src.ifidx = int32(info.Ifindex)
-
-			return
-		}
-	}
-}
-
-// pktInfoFromBuf returns type T populated from the provided buf via copy(). It
-// panics if buf is of insufficient size.
-func pktInfoFromBuf[T unix.Inet4Pktinfo | unix.Inet6Pktinfo](buf []byte) (t T) {
-	size := int(unsafe.Sizeof(t))
-	if len(buf) < size {
-		panic("pktInfoFromBuf: buffer too small")
-	}
-	copy(unsafe.Slice((*byte)(unsafe.Pointer(&t)), size), buf)
-	return t
-}
-
-// setSrcControl sets an IP{V6}_PKTINFO in control based on the source address
-// and source ifindex found in ep. control's len will be set to 0 in the event
-// that ep is a default value.
-func setSrcControl(control *[]byte, ep *StdNetEndpoint) {
-	*control = (*control)[:cap(*control)]
-	if len(*control) < int(unsafe.Sizeof(unix.Cmsghdr{})) {
-		*control = (*control)[:0]
-		return
-	}
-
-	if ep.src.ifidx == 0 && !ep.SrcIP().IsValid() {
-		*control = (*control)[:0]
-		return
-	}
-
-	if len(*control) < srcControlSize {
-		*control = (*control)[:0]
-		return
-	}
-
-	hdr := (*unix.Cmsghdr)(unsafe.Pointer(&(*control)[0]))
-	if ep.SrcIP().Is4() {
-		hdr.Level = unix.IPPROTO_IP
-		hdr.Type = unix.IP_PKTINFO
-		hdr.SetLen(unix.CmsgLen(unix.SizeofInet4Pktinfo))
-
-		info := (*unix.Inet4Pktinfo)(unsafe.Pointer(&(*control)[unix.SizeofCmsghdr]))
-		info.Ifindex = ep.src.ifidx
-		if ep.SrcIP().IsValid() {
-			info.Spec_dst = ep.SrcIP().As4()
-		}
-		*control = (*control)[:unix.CmsgSpace(unix.SizeofInet4Pktinfo)]
-	} else {
-		hdr.Level = unix.IPPROTO_IPV6
-		hdr.Type = unix.IPV6_PKTINFO
-		hdr.SetLen(unix.CmsgLen(unix.SizeofInet6Pktinfo))
-
-		info := (*unix.Inet6Pktinfo)(unsafe.Pointer(&(*control)[unix.SizeofCmsghdr]))
-		info.Ifindex = uint32(ep.src.ifidx)
-		if ep.SrcIP().IsValid() {
-			info.Addr = ep.SrcIP().As16()
-		}
-		*control = (*control)[:unix.CmsgSpace(unix.SizeofInet6Pktinfo)]
-	}
-
-}
-
-var srcControlSize = unix.CmsgSpace(unix.SizeofInet6Pktinfo)
-
-const StdNetSupportsStickySockets = true

wgstack/tun/checksum.go

@@ -1,42 +0,0 @@
-package tun
-
-import "encoding/binary"
-
-// TODO: Explore SIMD and/or other assembly optimizations.
-func checksumNoFold(b []byte, initial uint64) uint64 {
-	ac := initial
-	i := 0
-	n := len(b)
-	for n >= 4 {
-		ac += uint64(binary.BigEndian.Uint32(b[i : i+4]))
-		n -= 4
-		i += 4
-	}
-	for n >= 2 {
-		ac += uint64(binary.BigEndian.Uint16(b[i : i+2]))
-		n -= 2
-		i += 2
-	}
-	if n == 1 {
-		ac += uint64(b[i]) << 8
-	}
-	return ac
-}
-
-func checksum(b []byte, initial uint64) uint16 {
-	ac := checksumNoFold(b, initial)
-	ac = (ac >> 16) + (ac & 0xffff)
-	ac = (ac >> 16) + (ac & 0xffff)
-	ac = (ac >> 16) + (ac & 0xffff)
-	ac = (ac >> 16) + (ac & 0xffff)
-	return uint16(ac)
-}
-
-func pseudoHeaderChecksumNoFold(protocol uint8, srcAddr, dstAddr []byte, totalLen uint16) uint64 {
-	sum := checksumNoFold(srcAddr, 0)
-	sum = checksumNoFold(dstAddr, sum)
-	sum = checksumNoFold([]byte{0, protocol}, sum)
-	tmp := make([]byte, 2)
-	binary.BigEndian.PutUint16(tmp, totalLen)
-	return checksumNoFold(tmp, sum)
-}

wgstack/tun/export.go

@@ -1,3 +0,0 @@
-package tun
-
-const VirtioNetHdrLen = virtioNetHdrLen

wgstack/tun/tcp_offload_linux.go

@@ -1,630 +0,0 @@
-//go:build linux
-
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package tun
-
-import (
-	"bytes"
-	"encoding/binary"
-	"errors"
-	"io"
-	"unsafe"
-
-	wgconn "github.com/slackhq/nebula/wgstack/conn"
-	"golang.org/x/sys/unix"
-)
-
-var ErrTooManySegments = errors.New("tun: too many segments for TSO")
-
-const tcpFlagsOffset = 13
-
-const (
-	tcpFlagFIN uint8 = 0x01
-	tcpFlagPSH uint8 = 0x08
-	tcpFlagACK uint8 = 0x10
-)
-
-// virtioNetHdr is defined in the kernel in include/uapi/linux/virtio_net.h. The
-// kernel symbol is virtio_net_hdr.
-type virtioNetHdr struct {
-	flags      uint8
-	gsoType    uint8
-	hdrLen     uint16
-	gsoSize    uint16
-	csumStart  uint16
-	csumOffset uint16
-}
-
-func (v *virtioNetHdr) decode(b []byte) error {
-	if len(b) < virtioNetHdrLen {
-		return io.ErrShortBuffer
-	}
-	copy(unsafe.Slice((*byte)(unsafe.Pointer(v)), virtioNetHdrLen), b[:virtioNetHdrLen])
-	return nil
-}
-
-func (v *virtioNetHdr) encode(b []byte) error {
-	if len(b) < virtioNetHdrLen {
-		return io.ErrShortBuffer
-	}
-	copy(b[:virtioNetHdrLen], unsafe.Slice((*byte)(unsafe.Pointer(v)), virtioNetHdrLen))
-	return nil
-}
-
-const (
-	// virtioNetHdrLen is the length in bytes of virtioNetHdr. This matches the
-	// shape of the C ABI for its kernel counterpart -- sizeof(virtio_net_hdr).
-	virtioNetHdrLen = int(unsafe.Sizeof(virtioNetHdr{}))
-)
-
-// flowKey represents the key for a flow.
-type flowKey struct {
-	srcAddr, dstAddr [16]byte
-	srcPort, dstPort uint16
-	rxAck            uint32 // varying ack values should not be coalesced. Treat them as separate flows.
-}
-
-// tcpGROTable holds flow and coalescing information for the purposes of GRO.
-type tcpGROTable struct {
-	itemsByFlow map[flowKey][]tcpGROItem
-	itemsPool   [][]tcpGROItem
-}
-
-func newTCPGROTable() *tcpGROTable {
-	t := &tcpGROTable{
-		itemsByFlow: make(map[flowKey][]tcpGROItem, wgconn.IdealBatchSize),
-		itemsPool:   make([][]tcpGROItem, wgconn.IdealBatchSize),
-	}
-	for i := range t.itemsPool {
-		t.itemsPool[i] = make([]tcpGROItem, 0, wgconn.IdealBatchSize)
-	}
-	return t
-}
-
-func newFlowKey(pkt []byte, srcAddr, dstAddr, tcphOffset int) flowKey {
-	key := flowKey{}
-	addrSize := dstAddr - srcAddr
-	copy(key.srcAddr[:], pkt[srcAddr:dstAddr])
-	copy(key.dstAddr[:], pkt[dstAddr:dstAddr+addrSize])
-	key.srcPort = binary.BigEndian.Uint16(pkt[tcphOffset:])
-	key.dstPort = binary.BigEndian.Uint16(pkt[tcphOffset+2:])
-	key.rxAck = binary.BigEndian.Uint32(pkt[tcphOffset+8:])
-	return key
-}
-
-// lookupOrInsert looks up a flow for the provided packet and metadata,
-// returning the packets found for the flow, or inserting a new one if none
-// is found.
-func (t *tcpGROTable) lookupOrInsert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex int) ([]tcpGROItem, bool) {
-	key := newFlowKey(pkt, srcAddrOffset, dstAddrOffset, tcphOffset)
-	items, ok := t.itemsByFlow[key]
-	if ok {
-		return items, ok
-	}
-	// TODO: insert() performs another map lookup. This could be rearranged to avoid.
-	t.insert(pkt, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex)
-	return nil, false
-}
-
-// insert an item in the table for the provided packet and packet metadata.
-func (t *tcpGROTable) insert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex int) {
-	key := newFlowKey(pkt, srcAddrOffset, dstAddrOffset, tcphOffset)
-	item := tcpGROItem{
-		key:       key,
-		bufsIndex: uint16(bufsIndex),
-		gsoSize:   uint16(len(pkt[tcphOffset+tcphLen:])),
-		iphLen:    uint8(tcphOffset),
-		tcphLen:   uint8(tcphLen),
-		sentSeq:   binary.BigEndian.Uint32(pkt[tcphOffset+4:]),
-		pshSet:    pkt[tcphOffset+tcpFlagsOffset]&tcpFlagPSH != 0,
-	}
-	items, ok := t.itemsByFlow[key]
-	if !ok {
-		items = t.newItems()
-	}
-	items = append(items, item)
-	t.itemsByFlow[key] = items
-}
-
-func (t *tcpGROTable) updateAt(item tcpGROItem, i int) {
-	items, _ := t.itemsByFlow[item.key]
-	items[i] = item
-}
-
-func (t *tcpGROTable) deleteAt(key flowKey, i int) {
-	items, _ := t.itemsByFlow[key]
-	items = append(items[:i], items[i+1:]...)
-	t.itemsByFlow[key] = items
-}
-
-// tcpGROItem represents bookkeeping data for a TCP packet during the lifetime
-// of a GRO evaluation across a vector of packets.
-type tcpGROItem struct {
-	key       flowKey
-	sentSeq   uint32 // the sequence number
-	bufsIndex uint16 // the index into the original bufs slice
-	numMerged uint16 // the number of packets merged into this item
-	gsoSize   uint16 // payload size
-	iphLen    uint8  // ip header len
-	tcphLen   uint8  // tcp header len
-	pshSet    bool   // psh flag is set
-}
-
-func (t *tcpGROTable) newItems() []tcpGROItem {
-	var items []tcpGROItem
-	items, t.itemsPool = t.itemsPool[len(t.itemsPool)-1], t.itemsPool[:len(t.itemsPool)-1]
-	return items
-}
-
-func (t *tcpGROTable) reset() {
-	for k, items := range t.itemsByFlow {
-		items = items[:0]
-		t.itemsPool = append(t.itemsPool, items)
-		delete(t.itemsByFlow, k)
-	}
-}
-
-// canCoalesce represents the outcome of checking if two TCP packets are
-// candidates for coalescing.
-type canCoalesce int
-
-const (
-	coalescePrepend     canCoalesce = -1
-	coalesceUnavailable canCoalesce = 0
-	coalesceAppend      canCoalesce = 1
-)
-
-// tcpPacketsCanCoalesce evaluates if pkt can be coalesced with the packet
-// described by item. This function makes considerations that match the kernel's
-// GRO self tests, which can be found in tools/testing/selftests/net/gro.c.
-func tcpPacketsCanCoalesce(pkt []byte, iphLen, tcphLen uint8, seq uint32, pshSet bool, gsoSize uint16, item tcpGROItem, bufs [][]byte, bufsOffset int) canCoalesce {
-	pktTarget := bufs[item.bufsIndex][bufsOffset:]
-	if tcphLen != item.tcphLen {
-		// cannot coalesce with unequal tcp options len
-		return coalesceUnavailable
-	}
-	if tcphLen > 20 {
-		if !bytes.Equal(pkt[iphLen+20:iphLen+tcphLen], pktTarget[item.iphLen+20:iphLen+tcphLen]) {
-			// cannot coalesce with unequal tcp options
-			return coalesceUnavailable
-		}
-	}
-	if pkt[0]>>4 == 6 {
-		if pkt[0] != pktTarget[0] || pkt[1]>>4 != pktTarget[1]>>4 {
-			// cannot coalesce with unequal Traffic class values
-			return coalesceUnavailable
-		}
-		if pkt[7] != pktTarget[7] {
-			// cannot coalesce with unequal Hop limit values
-			return coalesceUnavailable
-		}
-	} else {
-		if pkt[1] != pktTarget[1] {
-			// cannot coalesce with unequal ToS values
-			return coalesceUnavailable
-		}
-		if pkt[6]>>5 != pktTarget[6]>>5 {
-			// cannot coalesce with unequal DF or reserved bits. MF is checked
-			// further up the stack.
-			return coalesceUnavailable
-		}
-		if pkt[8] != pktTarget[8] {
-			// cannot coalesce with unequal TTL values
-			return coalesceUnavailable
-		}
-	}
-	// seq adjacency
-	lhsLen := item.gsoSize
-	lhsLen += item.numMerged * item.gsoSize
-	if seq == item.sentSeq+uint32(lhsLen) { // pkt aligns following item from a seq num perspective
-		if item.pshSet {
-			// We cannot append to a segment that has the PSH flag set, PSH
-			// can only be set on the final segment in a reassembled group.
-			return coalesceUnavailable
-		}
-		if len(pktTarget[iphLen+tcphLen:])%int(item.gsoSize) != 0 {
-			// A smaller than gsoSize packet has been appended previously.
-			// Nothing can come after a smaller packet on the end.
-			return coalesceUnavailable
-		}
-		if gsoSize > item.gsoSize {
-			// We cannot have a larger packet following a smaller one.
-			return coalesceUnavailable
-		}
-		return coalesceAppend
-	} else if seq+uint32(gsoSize) == item.sentSeq { // pkt aligns in front of item from a seq num perspective
-		if pshSet {
-			// We cannot prepend with a segment that has the PSH flag set, PSH
-			// can only be set on the final segment in a reassembled group.
-			return coalesceUnavailable
-		}
-		if gsoSize < item.gsoSize {
-			// We cannot have a larger packet following a smaller one.
-			return coalesceUnavailable
-		}
-		if gsoSize > item.gsoSize && item.numMerged > 0 {
-			// There's at least one previous merge, and we're larger than all
-			// previous. This would put multiple smaller packets on the end.
-			return coalesceUnavailable
-		}
-		return coalescePrepend
-	}
-	return coalesceUnavailable
-}
-
-func tcpChecksumValid(pkt []byte, iphLen uint8, isV6 bool) bool {
-	srcAddrAt := ipv4SrcAddrOffset
-	addrSize := 4
-	if isV6 {
-		srcAddrAt = ipv6SrcAddrOffset
-		addrSize = 16
-	}
-	tcpTotalLen := uint16(len(pkt) - int(iphLen))
-	tcpCSumNoFold := pseudoHeaderChecksumNoFold(unix.IPPROTO_TCP, pkt[srcAddrAt:srcAddrAt+addrSize], pkt[srcAddrAt+addrSize:srcAddrAt+addrSize*2], tcpTotalLen)
-	return ^checksum(pkt[iphLen:], tcpCSumNoFold) == 0
-}
-
-// coalesceResult represents the result of attempting to coalesce two TCP
-// packets.
-type coalesceResult int
-
-const (
-	coalesceInsufficientCap coalesceResult = 0
-	coalescePSHEnding       coalesceResult = 1
-	coalesceItemInvalidCSum coalesceResult = 2
-	coalescePktInvalidCSum  coalesceResult = 3
-	coalesceSuccess         coalesceResult = 4
-)
-
-// coalesceTCPPackets attempts to coalesce pkt with the packet described by
-// item, returning the outcome. This function may swap bufs elements in the
-// event of a prepend as item's bufs index is already being tracked for writing
-// to a Device.
-func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize uint16, seq uint32, pshSet bool, item *tcpGROItem, bufs [][]byte, bufsOffset int, isV6 bool) coalesceResult {
-	var pktHead []byte // the packet that will end up at the front
-	headersLen := item.iphLen + item.tcphLen
-	coalescedLen := len(bufs[item.bufsIndex][bufsOffset:]) + len(pkt) - int(headersLen)
-
-	// Copy data
-	if mode == coalescePrepend {
-		pktHead = pkt
-		if cap(pkt)-bufsOffset < coalescedLen {
-			// We don't want to allocate a new underlying array if capacity is
-			// too small.
-			return coalesceInsufficientCap
-		}
-		if pshSet {
-			return coalescePSHEnding
-		}
-		if item.numMerged == 0 {
-			if !tcpChecksumValid(bufs[item.bufsIndex][bufsOffset:], item.iphLen, isV6) {
-				return coalesceItemInvalidCSum
-			}
-		}
-		if !tcpChecksumValid(pkt, item.iphLen, isV6) {
-			return coalescePktInvalidCSum
-		}
-		item.sentSeq = seq
-		extendBy := coalescedLen - len(pktHead)
-		bufs[pktBuffsIndex] = append(bufs[pktBuffsIndex], make([]byte, extendBy)...)
-		copy(bufs[pktBuffsIndex][bufsOffset+len(pkt):], bufs[item.bufsIndex][bufsOffset+int(headersLen):])
-		// Flip the slice headers in bufs as part of prepend. The index of item
-		// is already being tracked for writing.
-		bufs[item.bufsIndex], bufs[pktBuffsIndex] = bufs[pktBuffsIndex], bufs[item.bufsIndex]
-	} else {
-		pktHead = bufs[item.bufsIndex][bufsOffset:]
-		if cap(pktHead)-bufsOffset < coalescedLen {
-			// We don't want to allocate a new underlying array if capacity is
-			// too small.
-			return coalesceInsufficientCap
-		}
-		if item.numMerged == 0 {
-			if !tcpChecksumValid(bufs[item.bufsIndex][bufsOffset:], item.iphLen, isV6) {
-				return coalesceItemInvalidCSum
-			}
-		}
-		if !tcpChecksumValid(pkt, item.iphLen, isV6) {
-			return coalescePktInvalidCSum
-		}
-		if pshSet {
-			// We are appending a segment with PSH set.
-			item.pshSet = pshSet
-			pktHead[item.iphLen+tcpFlagsOffset] |= tcpFlagPSH
-		}
-		extendBy := len(pkt) - int(headersLen)
-		bufs[item.bufsIndex] = append(bufs[item.bufsIndex], make([]byte, extendBy)...)
-		copy(bufs[item.bufsIndex][bufsOffset+len(pktHead):], pkt[headersLen:])
-	}
-
-	if gsoSize > item.gsoSize {
-		item.gsoSize = gsoSize
-	}
-	hdr := virtioNetHdr{
-		flags:      unix.VIRTIO_NET_HDR_F_NEEDS_CSUM, // this turns into CHECKSUM_PARTIAL in the skb
-		hdrLen:     uint16(headersLen),
-		gsoSize:    uint16(item.gsoSize),
-		csumStart:  uint16(item.iphLen),
-		csumOffset: 16,
-	}
-
-	// Recalculate the total len (IPv4) or payload len (IPv6). Recalculate the
-	// (IPv4) header checksum.
-	if isV6 {
-		hdr.gsoType = unix.VIRTIO_NET_HDR_GSO_TCPV6
-		binary.BigEndian.PutUint16(pktHead[4:], uint16(coalescedLen)-uint16(item.iphLen)) // set new payload len
-	} else {
-		hdr.gsoType = unix.VIRTIO_NET_HDR_GSO_TCPV4
-		pktHead[10], pktHead[11] = 0, 0                               // clear checksum field
-		binary.BigEndian.PutUint16(pktHead[2:], uint16(coalescedLen)) // set new total length
-		iphCSum := ^checksum(pktHead[:item.iphLen], 0)                // compute checksum
-		binary.BigEndian.PutUint16(pktHead[10:], iphCSum)             // set checksum field
-	}
-	hdr.encode(bufs[item.bufsIndex][bufsOffset-virtioNetHdrLen:])
-
-	// Calculate the pseudo header checksum and place it at the TCP checksum
-	// offset. Downstream checksum offloading will combine this with computation
-	// of the tcp header and payload checksum.
-	addrLen := 4
-	addrOffset := ipv4SrcAddrOffset
-	if isV6 {
-		addrLen = 16
-		addrOffset = ipv6SrcAddrOffset
-	}
-	srcAddrAt := bufsOffset + addrOffset
-	srcAddr := bufs[item.bufsIndex][srcAddrAt : srcAddrAt+addrLen]
-	dstAddr := bufs[item.bufsIndex][srcAddrAt+addrLen : srcAddrAt+addrLen*2]
-	psum := pseudoHeaderChecksumNoFold(unix.IPPROTO_TCP, srcAddr, dstAddr, uint16(coalescedLen-int(item.iphLen)))
-	binary.BigEndian.PutUint16(pktHead[hdr.csumStart+hdr.csumOffset:], checksum([]byte{}, psum))
-
-	item.numMerged++
-	return coalesceSuccess
-}
-
-const (
-	ipv4FlagMoreFragments uint8 = 0x20
-)
-
-const (
-	ipv4SrcAddrOffset = 12
-	ipv6SrcAddrOffset = 8
-	maxUint16         = 1<<16 - 1
-)
-
-// tcpGRO evaluates the TCP packet at pktI in bufs for coalescing with
-// existing packets tracked in table. It will return false when pktI is not
-// coalesced, otherwise true. This indicates to the caller if bufs[pktI]
-// should be written to the Device.
-func tcpGRO(bufs [][]byte, offset int, pktI int, table *tcpGROTable, isV6 bool) (pktCoalesced bool) {
-	pkt := bufs[pktI][offset:]
-	if len(pkt) > maxUint16 {
-		// A valid IPv4 or IPv6 packet will never exceed this.
-		return false
-	}
-	iphLen := int((pkt[0] & 0x0F) * 4)
-	if isV6 {
-		iphLen = 40
-		ipv6HPayloadLen := int(binary.BigEndian.Uint16(pkt[4:]))
-		if ipv6HPayloadLen != len(pkt)-iphLen {
-			return false
-		}
-	} else {
-		totalLen := int(binary.BigEndian.Uint16(pkt[2:]))
-		if totalLen != len(pkt) {
-			return false
-		}
-	}
-	if len(pkt) < iphLen {
-		return false
-	}
-	tcphLen := int((pkt[iphLen+12] >> 4) * 4)
-	if tcphLen < 20 || tcphLen > 60 {
-		return false
-	}
-	if len(pkt) < iphLen+tcphLen {
-		return false
-	}
-	if !isV6 {
-		if pkt[6]&ipv4FlagMoreFragments != 0 || pkt[6]<<3 != 0 || pkt[7] != 0 {
-			// no GRO support for fragmented segments for now
-			return false
-		}
-	}
-	tcpFlags := pkt[iphLen+tcpFlagsOffset]
-	var pshSet bool
-	// not a candidate if any non-ACK flags (except PSH+ACK) are set
-	if tcpFlags != tcpFlagACK {
-		if pkt[iphLen+tcpFlagsOffset] != tcpFlagACK|tcpFlagPSH {
-			return false
-		}
-		pshSet = true
-	}
-	gsoSize := uint16(len(pkt) - tcphLen - iphLen)
-	// not a candidate if payload len is 0
-	if gsoSize < 1 {
-		return false
-	}
-	seq := binary.BigEndian.Uint32(pkt[iphLen+4:])
-	srcAddrOffset := ipv4SrcAddrOffset
-	addrLen := 4
-	if isV6 {
-		srcAddrOffset = ipv6SrcAddrOffset
-		addrLen = 16
-	}
-	items, existing := table.lookupOrInsert(pkt, srcAddrOffset, srcAddrOffset+addrLen, iphLen, tcphLen, pktI)
-	if !existing {
-		return false
-	}
-	for i := len(items) - 1; i >= 0; i-- {
-		// In the best case of packets arriving in order iterating in reverse is
-		// more efficient if there are multiple items for a given flow. This
-		// also enables a natural table.deleteAt() in the
-		// coalesceItemInvalidCSum case without the need for index tracking.
-		// This algorithm makes a best effort to coalesce in the event of
-		// unordered packets, where pkt may land anywhere in items from a
-		// sequence number perspective, however once an item is inserted into
-		// the table it is never compared across other items later.
-		item := items[i]
-		can := tcpPacketsCanCoalesce(pkt, uint8(iphLen), uint8(tcphLen), seq, pshSet, gsoSize, item, bufs, offset)
-		if can != coalesceUnavailable {
-			result := coalesceTCPPackets(can, pkt, pktI, gsoSize, seq, pshSet, &item, bufs, offset, isV6)
-			switch result {
-			case coalesceSuccess:
-				table.updateAt(item, i)
-				return true
-			case coalesceItemInvalidCSum:
-				// delete the item with an invalid csum
-				table.deleteAt(item.key, i)
-			case coalescePktInvalidCSum:
-				// no point in inserting an item that we can't coalesce
-				return false
-			default:
-			}
-		}
-	}
-	// failed to coalesce with any other packets; store the item in the flow
-	table.insert(pkt, srcAddrOffset, srcAddrOffset+addrLen, iphLen, tcphLen, pktI)
-	return false
-}
-
-func isTCP4NoIPOptions(b []byte) bool {
-	if len(b) < 40 {
-		return false
-	}
-	if b[0]>>4 != 4 {
-		return false
-	}
-	if b[0]&0x0F != 5 {
-		return false
-	}
-	if b[9] != unix.IPPROTO_TCP {
-		return false
-	}
-	return true
-}
-
-func isTCP6NoEH(b []byte) bool {
-	if len(b) < 60 {
-		return false
-	}
-	if b[0]>>4 != 6 {
-		return false
-	}
-	if b[6] != unix.IPPROTO_TCP {
-		return false
-	}
-	return true
-}
-
-// handleGRO evaluates bufs for GRO, and writes the indices of the resulting
-// packets into toWrite. toWrite, tcp4Table, and tcp6Table should initially be
-// empty (but non-nil), and are passed in to save allocs as the caller may reset
-// and recycle them across vectors of packets.
-func handleGRO(bufs [][]byte, offset int, tcp4Table, tcp6Table *tcpGROTable, toWrite *[]int) error {
-	for i := range bufs {
-		if offset < virtioNetHdrLen || offset > len(bufs[i])-1 {
-			return errors.New("invalid offset")
-		}
-		var coalesced bool
-		switch {
-		case isTCP4NoIPOptions(bufs[i][offset:]): // ipv4 packets w/IP options do not coalesce
-			coalesced = tcpGRO(bufs, offset, i, tcp4Table, false)
-		case isTCP6NoEH(bufs[i][offset:]): // ipv6 packets w/extension headers do not coalesce
-			coalesced = tcpGRO(bufs, offset, i, tcp6Table, true)
-		}
-		if !coalesced {
-			hdr := virtioNetHdr{}
-			err := hdr.encode(bufs[i][offset-virtioNetHdrLen:])
-			if err != nil {
-				return err
-			}
-			*toWrite = append(*toWrite, i)
-		}
-	}
-	return nil
-}
-
-// tcpTSO splits packets from in into outBuffs, writing the size of each
-// element into sizes. It returns the number of buffers populated, and/or an
-// error.
-func tcpTSO(in []byte, hdr virtioNetHdr, outBuffs [][]byte, sizes []int, outOffset int) (int, error) {
-	iphLen := int(hdr.csumStart)
-	srcAddrOffset := ipv6SrcAddrOffset
-	addrLen := 16
-	if hdr.gsoType == unix.VIRTIO_NET_HDR_GSO_TCPV4 {
-		in[10], in[11] = 0, 0 // clear ipv4 header checksum
-		srcAddrOffset = ipv4SrcAddrOffset
-		addrLen = 4
-	}
-	tcpCSumAt := int(hdr.csumStart + hdr.csumOffset)
-	in[tcpCSumAt], in[tcpCSumAt+1] = 0, 0 // clear tcp checksum
-	firstTCPSeqNum := binary.BigEndian.Uint32(in[hdr.csumStart+4:])
-	nextSegmentDataAt := int(hdr.hdrLen)
-	i := 0
-	for ; nextSegmentDataAt < len(in); i++ {
-		if i == len(outBuffs) {
-			return i - 1, ErrTooManySegments
-		}
-		nextSegmentEnd := nextSegmentDataAt + int(hdr.gsoSize)
-		if nextSegmentEnd > len(in) {
-			nextSegmentEnd = len(in)
-		}
-		segmentDataLen := nextSegmentEnd - nextSegmentDataAt
-		totalLen := int(hdr.hdrLen) + segmentDataLen
-		sizes[i] = totalLen
-		out := outBuffs[i][outOffset:]
-
-		copy(out, in[:iphLen])
-		if hdr.gsoType == unix.VIRTIO_NET_HDR_GSO_TCPV4 {
-			// For IPv4 we are responsible for incrementing the ID field,
-			// updating the total len field, and recalculating the header
-			// checksum.
-			if i > 0 {
-				id := binary.BigEndian.Uint16(out[4:])
-				id += uint16(i)
-				binary.BigEndian.PutUint16(out[4:], id)
-			}
-			binary.BigEndian.PutUint16(out[2:], uint16(totalLen))
-			ipv4CSum := ^checksum(out[:iphLen], 0)
-			binary.BigEndian.PutUint16(out[10:], ipv4CSum)
-		} else {
-			// For IPv6 we are responsible for updating the payload length field.
-			binary.BigEndian.PutUint16(out[4:], uint16(totalLen-iphLen))
-		}
-
-		// TCP header
-		copy(out[hdr.csumStart:hdr.hdrLen], in[hdr.csumStart:hdr.hdrLen])
-		tcpSeq := firstTCPSeqNum + uint32(hdr.gsoSize*uint16(i))
-		binary.BigEndian.PutUint32(out[hdr.csumStart+4:], tcpSeq)
-		if nextSegmentEnd != len(in) {
-			// FIN and PSH should only be set on last segment
-			clearFlags := tcpFlagFIN | tcpFlagPSH
-			out[hdr.csumStart+tcpFlagsOffset] &^= clearFlags
-		}
-
-		// payload
-		copy(out[hdr.hdrLen:], in[nextSegmentDataAt:nextSegmentEnd])
-
-		// TCP checksum
-		tcpHLen := int(hdr.hdrLen - hdr.csumStart)
-		tcpLenForPseudo := uint16(tcpHLen + segmentDataLen)
-		tcpCSumNoFold := pseudoHeaderChecksumNoFold(unix.IPPROTO_TCP, in[srcAddrOffset:srcAddrOffset+addrLen], in[srcAddrOffset+addrLen:srcAddrOffset+addrLen*2], tcpLenForPseudo)
-		tcpCSum := ^checksum(out[hdr.csumStart:totalLen], tcpCSumNoFold)
-		binary.BigEndian.PutUint16(out[hdr.csumStart+hdr.csumOffset:], tcpCSum)
-
-		nextSegmentDataAt += int(hdr.gsoSize)
-	}
-	return i, nil
-}
-
-func gsoNoneChecksum(in []byte, cSumStart, cSumOffset uint16) error {
-	cSumAt := cSumStart + cSumOffset
-	// The initial value at the checksum offset should be summed with the
-	// checksum we compute. This is typically the pseudo-header checksum.
-	initial := binary.BigEndian.Uint16(in[cSumAt:])
-	in[cSumAt], in[cSumAt+1] = 0, 0
-	binary.BigEndian.PutUint16(in[cSumAt:], ^checksum(in[cSumStart:], uint64(initial)))
-	return nil
-}

wgstack/tun/tun.go

@@ -1,52 +0,0 @@
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package tun
-
-import (
-	"os"
-)
-
-type Event int
-
-const (
-	EventUp = 1 << iota
-	EventDown
-	EventMTUUpdate
-)
-
-type Device interface {
-	// File returns the file descriptor of the device.
-	File() *os.File
-
-	// Read one or more packets from the Device (without any additional headers).
-	// On a successful read it returns the number of packets read, and sets
-	// packet lengths within the sizes slice. len(sizes) must be >= len(bufs).
-	// A nonzero offset can be used to instruct the Device on where to begin
-	// reading into each element of the bufs slice.
-	Read(bufs [][]byte, sizes []int, offset int) (n int, err error)
-
-	// Write one or more packets to the device (without any additional headers).
-	// On a successful write it returns the number of packets written. A nonzero
-	// offset can be used to instruct the Device on where to begin writing from
-	// each packet contained within the bufs slice.
-	Write(bufs [][]byte, offset int) (int, error)
-
-	// MTU returns the MTU of the Device.
-	MTU() (int, error)
-
-	// Name returns the current name of the Device.
-	Name() (string, error)
-
-	// Events returns a channel of type Event, which is fed Device events.
-	Events() <-chan Event
-
-	// Close stops the Device and closes the Event channel.
-	Close() error
-
-	// BatchSize returns the preferred/max number of packets that can be read or
-	// written in a single read/write call. BatchSize must not change over the
-	// lifetime of a Device.
-	BatchSize() int
-}

wgstack/tun/tun_linux.go

@@ -1,664 +0,0 @@
-//go:build linux
-
-// SPDX-License-Identifier: MIT
-//
-// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
-
-package tun
-
-/* Implementation of the TUN device interface for linux
- */
-
-import (
-	"errors"
-	"fmt"
-	"os"
-	"sync"
-	"syscall"
-	"time"
-	"unsafe"
-
-	wgconn "github.com/slackhq/nebula/wgstack/conn"
-	"golang.org/x/sys/unix"
-	"golang.zx2c4.com/wireguard/rwcancel"
-)
-
-const (
-	cloneDevicePath = "/dev/net/tun"
-	ifReqSize       = unix.IFNAMSIZ + 64
-)
-
-type NativeTun struct {
-	tunFile                 *os.File
-	index                   int32      // if index
-	errors                  chan error // async error handling
-	events                  chan Event // device related events
-	netlinkSock             int
-	netlinkCancel           *rwcancel.RWCancel
-	hackListenerClosed      sync.Mutex
-	statusListenersShutdown chan struct{}
-	batchSize               int
-	vnetHdr                 bool
-
-	closeOnce sync.Once
-
-	nameOnce  sync.Once // guards calling initNameCache, which sets following fields
-	nameCache string    // name of interface
-	nameErr   error
-
-	readOpMu sync.Mutex                    // readOpMu guards readBuff
-	readBuff [virtioNetHdrLen + 65535]byte // if vnetHdr every read() is prefixed by virtioNetHdr
-
-	writeOpMu                  sync.Mutex // writeOpMu guards toWrite, tcp4GROTable, tcp6GROTable
-	toWrite                    []int
-	tcp4GROTable, tcp6GROTable *tcpGROTable
-}
-
-func (tun *NativeTun) File() *os.File {
-	return tun.tunFile
-}
-
-func (tun *NativeTun) routineHackListener() {
-	defer tun.hackListenerClosed.Unlock()
-	/* This is needed for the detection to work across network namespaces
-	 * If you are reading this and know a better method, please get in touch.
-	 */
-	last := 0
-	const (
-		up   = 1
-		down = 2
-	)
-	for {
-		sysconn, err := tun.tunFile.SyscallConn()
-		if err != nil {
-			return
-		}
-		err2 := sysconn.Control(func(fd uintptr) {
-			_, err = unix.Write(int(fd), nil)
-		})
-		if err2 != nil {
-			return
-		}
-		switch err {
-		case unix.EINVAL:
-			if last != up {
-				// If the tunnel is up, it reports that write() is
-				// allowed but we provided invalid data.
-				tun.events <- EventUp
-				last = up
-			}
-		case unix.EIO:
-			if last != down {
-				// If the tunnel is down, it reports that no I/O
-				// is possible, without checking our provided data.
-				tun.events <- EventDown
-				last = down
-			}
-		default:
-			return
-		}
-		select {
-		case <-time.After(time.Second):
-			// nothing
-		case <-tun.statusListenersShutdown:
-			return
-		}
-	}
-}
-
-func createNetlinkSocket() (int, error) {
-	sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW|unix.SOCK_CLOEXEC, unix.NETLINK_ROUTE)
-	if err != nil {
-		return -1, err
-	}
-	saddr := &unix.SockaddrNetlink{
-		Family: unix.AF_NETLINK,
-		Groups: unix.RTMGRP_LINK | unix.RTMGRP_IPV4_IFADDR | unix.RTMGRP_IPV6_IFADDR,
-	}
-	err = unix.Bind(sock, saddr)
-	if err != nil {
-		return -1, err
-	}
-	return sock, nil
-}
-
-func (tun *NativeTun) routineNetlinkListener() {
-	defer func() {
-		unix.Close(tun.netlinkSock)
-		tun.hackListenerClosed.Lock()
-		close(tun.events)
-		tun.netlinkCancel.Close()
-	}()
-
-	for msg := make([]byte, 1<<16); ; {
-		var err error
-		var msgn int
-		for {
-			msgn, _, _, _, err = unix.Recvmsg(tun.netlinkSock, msg[:], nil, 0)
-			if err == nil || !rwcancel.RetryAfterError(err) {
-				break
-			}
-			if !tun.netlinkCancel.ReadyRead() {
-				tun.errors <- fmt.Errorf("netlink socket closed: %w", err)
-				return
-			}
-		}
-		if err != nil {
-			tun.errors <- fmt.Errorf("failed to receive netlink message: %w", err)
-			return
-		}
-
-		select {
-		case <-tun.statusListenersShutdown:
-			return
-		default:
-		}
-
-		wasEverUp := false
-		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
-
-			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
-
-			if int(hdr.Len) > len(remain) {
-				break
-			}
-
-			switch hdr.Type {
-			case unix.NLMSG_DONE:
-				remain = []byte{}
-
-			case unix.RTM_NEWLINK:
-				info := *(*unix.IfInfomsg)(unsafe.Pointer(&remain[unix.SizeofNlMsghdr]))
-				remain = remain[hdr.Len:]
-
-				if info.Index != tun.index {
-					// not our interface
-					continue
-				}
-
-				if info.Flags&unix.IFF_RUNNING != 0 {
-					tun.events <- EventUp
-					wasEverUp = true
-				}
-
-				if info.Flags&unix.IFF_RUNNING == 0 {
-					// Don't emit EventDown before we've ever emitted EventUp.
-					// This avoids a startup race with HackListener, which
-					// might detect Up before we have finished reporting Down.
-					if wasEverUp {
-						tun.events <- EventDown
-					}
-				}
-
-				tun.events <- EventMTUUpdate
-
-			default:
-				remain = remain[hdr.Len:]
-			}
-		}
-	}
-}
-
-func getIFIndex(name string) (int32, error) {
-	fd, err := unix.Socket(
-		unix.AF_INET,
-		unix.SOCK_DGRAM|unix.SOCK_CLOEXEC,
-		0,
-	)
-	if err != nil {
-		return 0, err
-	}
-
-	defer unix.Close(fd)
-
-	var ifr [ifReqSize]byte
-	copy(ifr[:], name)
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCGIFINDEX),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-
-	if errno != 0 {
-		return 0, errno
-	}
-
-	return *(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])), nil
-}
-
-func (tun *NativeTun) setMTU(n int) error {
-	name, err := tun.Name()
-	if err != nil {
-		return err
-	}
-
-	// open datagram socket
-	fd, err := unix.Socket(
-		unix.AF_INET,
-		unix.SOCK_DGRAM|unix.SOCK_CLOEXEC,
-		0,
-	)
-	if err != nil {
-		return err
-	}
-	defer unix.Close(fd)
-
-	var ifr [ifReqSize]byte
-	copy(ifr[:], name)
-	*(*uint32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])) = uint32(n)
-
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCSIFMTU),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-
-	if errno != 0 {
-		return errno
-	}
-	return nil
-}
-
-func (tun *NativeTun) routineNetlinkRead() {
-	defer func() {
-		unix.Close(tun.netlinkSock)
-		tun.hackListenerClosed.Lock()
-		close(tun.events)
-		tun.netlinkCancel.Close()
-	}()
-
-	for msg := make([]byte, 1<<16); ; {
-		var err error
-		var msgn int
-		for {
-			msgn, _, _, _, err = unix.Recvmsg(tun.netlinkSock, msg[:], nil, 0)
-			if err == nil || !rwcancel.RetryAfterError(err) {
-				break
-			}
-			if !tun.netlinkCancel.ReadyRead() {
-				tun.errors <- fmt.Errorf("netlink socket closed: %w", err)
-				return
-			}
-		}
-		if err != nil {
-			tun.errors <- fmt.Errorf("failed to receive netlink message: %w", err)
-			return
-		}
-
-		wasEverUp := false
-		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
-
-			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
-
-			if int(hdr.Len) > len(remain) {
-				break
-			}
-
-			switch hdr.Type {
-			case unix.NLMSG_DONE:
-				remain = []byte{}
-
-			case unix.RTM_NEWLINK:
-				info := *(*unix.IfInfomsg)(unsafe.Pointer(&remain[unix.SizeofNlMsghdr]))
-				remain = remain[hdr.Len:]
-
-				if info.Index != tun.index {
-					continue
-				}
-
-				if info.Flags&unix.IFF_RUNNING != 0 {
-					tun.events <- EventUp
-					wasEverUp = true
-				}
-
-				if info.Flags&unix.IFF_RUNNING == 0 {
-					if wasEverUp {
-						tun.events <- EventDown
-					}
-				}
-				tun.events <- EventMTUUpdate
-
-			default:
-				remain = remain[hdr.Len:]
-			}
-		}
-	}
-}
-
-func (tun *NativeTun) routineNetlink() {
-	var err error
-
-	tun.netlinkSock, err = createNetlinkSocket()
-	if err != nil {
-		tun.errors <- fmt.Errorf("failed to create netlink socket: %w", err)
-		return
-	}
-
-	tun.netlinkCancel, err = rwcancel.NewRWCancel(tun.netlinkSock)
-	if err != nil {
-		tun.errors <- fmt.Errorf("failed to create netlink cancel: %w", err)
-		return
-	}
-
-	go tun.routineNetlinkListener()
-}
-
-func (tun *NativeTun) Close() error {
-	var err1, err2 error
-	tun.closeOnce.Do(func() {
-		if tun.statusListenersShutdown != nil {
-			close(tun.statusListenersShutdown)
-			if tun.netlinkCancel != nil {
-				err1 = tun.netlinkCancel.Cancel()
-			}
-		} else if tun.events != nil {
-			close(tun.events)
-		}
-		err2 = tun.tunFile.Close()
-	})
-	if err1 != nil {
-		return err1
-	}
-	return err2
-}
-
-func (tun *NativeTun) BatchSize() int {
-	return tun.batchSize
-}
-
-const (
-	// TODO: support TSO with ECN bits
-	tunOffloads = unix.TUN_F_CSUM | unix.TUN_F_TSO4 | unix.TUN_F_TSO6
-)
-
-func (tun *NativeTun) initFromFlags(name string) error {
-	sc, err := tun.tunFile.SyscallConn()
-	if err != nil {
-		return err
-	}
-	if e := sc.Control(func(fd uintptr) {
-		var (
-			ifr *unix.Ifreq
-		)
-		ifr, err = unix.NewIfreq(name)
-		if err != nil {
-			return
-		}
-		err = unix.IoctlIfreq(int(fd), unix.TUNGETIFF, ifr)
-		if err != nil {
-			return
-		}
-		got := ifr.Uint16()
-		if got&unix.IFF_VNET_HDR != 0 {
-			err = unix.IoctlSetInt(int(fd), unix.TUNSETOFFLOAD, tunOffloads)
-			if err != nil {
-				return
-			}
-			tun.vnetHdr = true
-			tun.batchSize = wgconn.IdealBatchSize
-		} else {
-			tun.batchSize = 1
-		}
-	}); e != nil {
-		return e
-	}
-	return err
-}
-
-// CreateTUN creates a Device with the provided name and MTU.
-func CreateTUN(name string, mtu int) (Device, error) {
-	nfd, err := unix.Open(cloneDevicePath, unix.O_RDWR|unix.O_CLOEXEC, 0)
-	if err != nil {
-		return nil, fmt.Errorf("CreateTUN(%q) failed; %s does not exist", name, cloneDevicePath)
-	}
-	fd := os.NewFile(uintptr(nfd), cloneDevicePath)
-	tun, err := CreateTUNFromFile(fd, mtu)
-	if err != nil {
-		return nil, err
-	}
-	if name != "tun" {
-		if err := tun.(*NativeTun).initFromFlags(name); err != nil {
-			tun.Close()
-			return nil, fmt.Errorf("CreateTUN(%q) failed to set flags: %w", name, err)
-		}
-	}
-	return tun, nil
-}
-
-// CreateTUNFromFile creates a Device from an os.File with the provided MTU.
-func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
-	tun := &NativeTun{
-		tunFile: file,
-		errors:  make(chan error, 5),
-		events:  make(chan Event, 5),
-	}
-
-	name, err := tun.Name()
-	if err != nil {
-		return nil, fmt.Errorf("failed to determine TUN name: %w", err)
-	}
-
-	if err := tun.initFromFlags(name); err != nil {
-		return nil, fmt.Errorf("failed to query TUN flags: %w", err)
-	}
-
-	if tun.batchSize == 0 {
-		tun.batchSize = 1
-	}
-
-	tun.index, err = getIFIndex(name)
-	if err != nil {
-		return nil, fmt.Errorf("failed to get TUN index: %w", err)
-	}
-
-	if err = tun.setMTU(mtu); err != nil {
-		return nil, fmt.Errorf("failed to set MTU: %w", err)
-	}
-
-	tun.statusListenersShutdown = make(chan struct{})
-	go tun.routineNetlink()
-
-	if tun.batchSize == 0 {
-		tun.batchSize = 1
-	}
-
-	tun.tcp4GROTable = newTCPGROTable()
-	tun.tcp6GROTable = newTCPGROTable()
-
-	return tun, nil
-}
-
-func (tun *NativeTun) Name() (string, error) {
-	tun.nameOnce.Do(tun.initNameCache)
-	return tun.nameCache, tun.nameErr
-}
-
-func (tun *NativeTun) initNameCache() {
-	sysconn, err := tun.tunFile.SyscallConn()
-	if err != nil {
-		tun.nameErr = err
-		return
-	}
-	err = sysconn.Control(func(fd uintptr) {
-		var ifr [ifReqSize]byte
-		_, _, errno := unix.Syscall(
-			unix.SYS_IOCTL,
-			fd,
-			uintptr(unix.TUNGETIFF),
-			uintptr(unsafe.Pointer(&ifr[0])),
-		)
-		if errno != 0 {
-			tun.nameErr = errno
-			return
-		}
-		tun.nameCache = unix.ByteSliceToString(ifr[:])
-	})
-	if err != nil && tun.nameErr == nil {
-		tun.nameErr = err
-	}
-}
-
-func (tun *NativeTun) MTU() (int, error) {
-	name, err := tun.Name()
-	if err != nil {
-		return 0, err
-	}
-
-	// open datagram socket
-	fd, err := unix.Socket(
-		unix.AF_INET,
-		unix.SOCK_DGRAM|unix.SOCK_CLOEXEC,
-		0,
-	)
-	if err != nil {
-		return 0, err
-	}
-	defer unix.Close(fd)
-
-	var ifr [ifReqSize]byte
-	copy(ifr[:], name)
-
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCGIFMTU),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-
-	if errno != 0 {
-		return 0, errno
-	}
-
-	return int(*(*uint32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ]))), nil
-}
-
-func (tun *NativeTun) Events() <-chan Event {
-	return tun.events
-}
-
-func (tun *NativeTun) Write(bufs [][]byte, offset int) (int, error) {
-	tun.writeOpMu.Lock()
-	defer func() {
-		tun.tcp4GROTable.reset()
-		tun.tcp6GROTable.reset()
-		tun.writeOpMu.Unlock()
-	}()
-	var (
-		errs  error
-		total int
-	)
-	tun.toWrite = tun.toWrite[:0]
-	if tun.vnetHdr {
-		err := handleGRO(bufs, offset, tun.tcp4GROTable, tun.tcp6GROTable, &tun.toWrite)
-		if err != nil {
-			return 0, err
-		}
-		offset -= virtioNetHdrLen
-	} else {
-		for i := range bufs {
-			tun.toWrite = append(tun.toWrite, i)
-		}
-	}
-	for _, bufsI := range tun.toWrite {
-		n, err := tun.tunFile.Write(bufs[bufsI][offset:])
-		if errors.Is(err, syscall.EBADFD) {
-			return total, os.ErrClosed
-		}
-		if err != nil {
-			errs = errors.Join(errs, err)
-		} else {
-			total += n
-		}
-	}
-	return total, errs
-}
-
-// handleVirtioRead splits in into bufs, leaving offset bytes at the front of
-// each buffer. It mutates sizes to reflect the size of each element of bufs,
-// and returns the number of packets read.
-func handleVirtioRead(in []byte, bufs [][]byte, sizes []int, offset int) (int, error) {
-	var hdr virtioNetHdr
-	if err := hdr.decode(in); err != nil {
-		return 0, err
-	}
-	in = in[virtioNetHdrLen:]
-	if hdr.gsoType == unix.VIRTIO_NET_HDR_GSO_NONE {
-		if hdr.flags&unix.VIRTIO_NET_HDR_F_NEEDS_CSUM != 0 {
-			if err := gsoNoneChecksum(in, hdr.csumStart, hdr.csumOffset); err != nil {
-				return 0, err
-			}
-		}
-		if len(in) > len(bufs[0][offset:]) {
-			return 0, fmt.Errorf("read len %d overflows bufs element len %d", len(in), len(bufs[0][offset:]))
-		}
-		n := copy(bufs[0][offset:], in)
-		sizes[0] = n
-		return 1, nil
-	}
-	if hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV4 && hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV6 {
-		return 0, fmt.Errorf("unsupported virtio GSO type: %d", hdr.gsoType)
-	}
-
-	ipVersion := in[0] >> 4
-	switch ipVersion {
-	case 4:
-		if hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV4 {
-			return 0, fmt.Errorf("ip header version: %d, GSO type: %d", ipVersion, hdr.gsoType)
-		}
-	case 6:
-		if hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV6 {
-			return 0, fmt.Errorf("ip header version: %d, GSO type: %d", ipVersion, hdr.gsoType)
-		}
-	default:
-		return 0, fmt.Errorf("invalid ip header version: %d", ipVersion)
-	}
-
-	if len(in) <= int(hdr.csumStart+12) {
-		return 0, errors.New("packet is too short")
-	}
-	tcpHLen := uint16(in[hdr.csumStart+12] >> 4 * 4)
-	if tcpHLen < 20 || tcpHLen > 60 {
-		return 0, fmt.Errorf("tcp header len is invalid: %d", tcpHLen)
-	}
-	hdr.hdrLen = hdr.csumStart + tcpHLen
-	if len(in) < int(hdr.hdrLen) {
-		return 0, fmt.Errorf("length of packet (%d) < virtioNetHdr.hdrLen (%d)", len(in), hdr.hdrLen)
-	}
-	if hdr.hdrLen < hdr.csumStart {
-		return 0, fmt.Errorf("virtioNetHdr.hdrLen (%d) < virtioNetHdr.csumStart (%d)", hdr.hdrLen, hdr.csumStart)
-	}
-	cSumAt := int(hdr.csumStart + hdr.csumOffset)
-	if cSumAt+1 >= len(in) {
-		return 0, fmt.Errorf("end of checksum offset (%d) exceeds packet length (%d)", cSumAt+1, len(in))
-	}
-
-	return tcpTSO(in, hdr, bufs, sizes, offset)
-}
-
-func (tun *NativeTun) Read(bufs [][]byte, sizes []int, offset int) (int, error) {
-	tun.readOpMu.Lock()
-	defer tun.readOpMu.Unlock()
-	select {
-	case err := <-tun.errors:
-		return 0, err
-	default:
-		readInto := bufs[0][offset:]
-		if tun.vnetHdr {
-			readInto = tun.readBuff[:]
-		}
-		n, err := tun.tunFile.Read(readInto)
-		if errors.Is(err, syscall.EBADFD) {
-			err = os.ErrClosed
-		}
-		if err != nil {
-			return 0, err
-		}
-		if tun.vnetHdr {
-			return handleVirtioRead(readInto[:n], bufs, sizes, offset)
-		}
-		sizes[0] = n
-		return 1, nil
-	}
-}