Use an interface for udp conns (#901)

connection_manager_test.go

@@ -54,10 +54,10 @@ func Test_NewConnectionManagerTest(t *testing.T) {
 	ifce := &Interface{
 		hostMap:          hostMap,
 		inside:           &test.NoopTun{},
-		outside:          &udp.Conn{},
+		outside:          &udp.NoopConn{},
 		firewall:         &Firewall{},
 		lightHouse:       lh,
-		handshakeManager: NewHandshakeManager(l, vpncidr, preferredRanges, hostMap, lh, &udp.Conn{}, defaultHandshakeConfig),
+		handshakeManager: NewHandshakeManager(l, vpncidr, preferredRanges, hostMap, lh, &udp.NoopConn{}, defaultHandshakeConfig),
 		l:                l,
 	}
 	ifce.certState.Store(cs)
@@ -133,10 +133,10 @@ func Test_NewConnectionManagerTest2(t *testing.T) {
 	ifce := &Interface{
 		hostMap:          hostMap,
 		inside:           &test.NoopTun{},
-		outside:          &udp.Conn{},
+		outside:          &udp.NoopConn{},
 		firewall:         &Firewall{},
 		lightHouse:       lh,
-		handshakeManager: NewHandshakeManager(l, vpncidr, preferredRanges, hostMap, lh, &udp.Conn{}, defaultHandshakeConfig),
+		handshakeManager: NewHandshakeManager(l, vpncidr, preferredRanges, hostMap, lh, &udp.NoopConn{}, defaultHandshakeConfig),
 		l:                l,
 	}
 	ifce.certState.Store(cs)
@@ -252,10 +252,10 @@ func Test_NewConnectionManagerTest_DisconnectInvalid(t *testing.T) {
 	ifce := &Interface{
 		hostMap:           hostMap,
 		inside:            &test.NoopTun{},
-		outside:           &udp.Conn{},
+		outside:           &udp.NoopConn{},
 		firewall:          &Firewall{},
 		lightHouse:        lh,
-		handshakeManager:  NewHandshakeManager(l, vpncidr, preferredRanges, hostMap, lh, &udp.Conn{}, defaultHandshakeConfig),
+		handshakeManager:  NewHandshakeManager(l, vpncidr, preferredRanges, hostMap, lh, &udp.NoopConn{}, defaultHandshakeConfig),
 		l:                 l,
 		disconnectInvalid: true,
 		caPool:            ncp,

control_tester.go

@@ -21,7 +21,7 @@ import (
 func (c *Control) WaitForType(msgType header.MessageType, subType header.MessageSubType, pipeTo *Control) {
 	h := &header.H{}
 	for {
-		p := c.f.outside.Get(true)
+		p := c.f.outside.(*udp.TesterConn).Get(true)
 		if err := h.Parse(p.Data); err != nil {
 			panic(err)
 		}
@@ -37,7 +37,7 @@ func (c *Control) WaitForType(msgType header.MessageType, subType header.Message
 func (c *Control) WaitForTypeByIndex(toIndex uint32, msgType header.MessageType, subType header.MessageSubType, pipeTo *Control) {
 	h := &header.H{}
 	for {
-		p := c.f.outside.Get(true)
+		p := c.f.outside.(*udp.TesterConn).Get(true)
 		if err := h.Parse(p.Data); err != nil {
 			panic(err)
 		}
@@ -90,11 +90,11 @@ func (c *Control) GetFromTun(block bool) []byte {
 
 // GetFromUDP will pull a udp packet off the udp side of nebula
 func (c *Control) GetFromUDP(block bool) *udp.Packet {
-	return c.f.outside.Get(block)
+	return c.f.outside.(*udp.TesterConn).Get(block)
 }
 
 func (c *Control) GetUDPTxChan() <-chan *udp.Packet {
-	return c.f.outside.TxPackets
+	return c.f.outside.(*udp.TesterConn).TxPackets
 }
 
 func (c *Control) GetTunTxChan() <-chan []byte {
@@ -103,7 +103,7 @@ func (c *Control) GetTunTxChan() <-chan []byte {
 
 // InjectUDPPacket will inject a packet into the udp side of nebula
 func (c *Control) InjectUDPPacket(p *udp.Packet) {
-	c.f.outside.Send(p)
+	c.f.outside.(*udp.TesterConn).Send(p)
 }
 
 // InjectTunUDPPacket puts a udp packet on the tun interface. Using UDP here because it's a simpler protocol
@@ -143,7 +143,7 @@ func (c *Control) GetVpnIp() iputil.VpnIp {
 }
 
 func (c *Control) GetUDPAddr() string {
-	return c.f.outside.Addr.String()
+	return c.f.outside.(*udp.TesterConn).Addr.String()
 }
 
 func (c *Control) KillPendingTunnel(vpnIp net.IP) bool {

handshake_manager.go

@@ -45,7 +45,7 @@ type HandshakeManager struct {
 	pendingHostMap         *HostMap
 	mainHostMap            *HostMap
 	lightHouse             *LightHouse
-	outside                *udp.Conn
+	outside                udp.Conn
 	config                 HandshakeConfig
 	OutboundHandshakeTimer *LockingTimerWheel[iputil.VpnIp]
 	messageMetrics         *MessageMetrics
@@ -57,7 +57,7 @@ type HandshakeManager struct {
 	trigger chan iputil.VpnIp
 }
 
-func NewHandshakeManager(l *logrus.Logger, tunCidr *net.IPNet, preferredRanges []*net.IPNet, mainHostMap *HostMap, lightHouse *LightHouse, outside *udp.Conn, config HandshakeConfig) *HandshakeManager {
+func NewHandshakeManager(l *logrus.Logger, tunCidr *net.IPNet, preferredRanges []*net.IPNet, mainHostMap *HostMap, lightHouse *LightHouse, outside udp.Conn, config HandshakeConfig) *HandshakeManager {
 	return &HandshakeManager{
 		pendingHostMap:         NewHostMap(l, "pending", tunCidr, preferredRanges),
 		mainHostMap:            mainHostMap,

handshake_manager_test.go

@@ -23,7 +23,7 @@ func Test_NewHandshakeManagerVpnIp(t *testing.T) {
 	mainHM := NewHostMap(l, "test", vpncidr, preferredRanges)
 	lh := newTestLighthouse()
 
-	blah := NewHandshakeManager(l, tuncidr, preferredRanges, mainHM, lh, &udp.Conn{}, defaultHandshakeConfig)
+	blah := NewHandshakeManager(l, tuncidr, preferredRanges, mainHM, lh, &udp.NoopConn{}, defaultHandshakeConfig)
 
 	now := time.Now()
 	blah.NextOutboundHandshakeTimerTick(now, mw)

interface.go

@@ -26,7 +26,7 @@ const mtu = 9001
 
 type InterfaceConfig struct {
 	HostMap                 *HostMap
-	Outside                 *udp.Conn
+	Outside                 udp.Conn
 	Inside                  overlay.Device
 	certState               *CertState
 	Cipher                  string
@@ -52,7 +52,7 @@ type InterfaceConfig struct {
 
 type Interface struct {
 	hostMap            *HostMap
-	outside            *udp.Conn
+	outside            udp.Conn
 	inside             overlay.Device
 	certState          atomic.Pointer[CertState]
 	cipher             string
@@ -80,7 +80,7 @@ type Interface struct {
 
 	conntrackCacheTimeout time.Duration
 
-	writers []*udp.Conn
+	writers []udp.Conn
 	readers []io.ReadWriteCloser
 
 	metricHandshakes    metrics.Histogram
@@ -167,7 +167,7 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 		dropMulticast:      c.DropMulticast,
 		routines:           c.routines,
 		version:            c.version,
-		writers:            make([]*udp.Conn, c.routines),
+		writers:            make([]udp.Conn, c.routines),
 		readers:            make([]io.ReadWriteCloser, c.routines),
 		caPool:             c.caPool,
 		disconnectInvalid:  c.disconnectInvalid,
@@ -243,7 +243,7 @@ func (f *Interface) run() {
 func (f *Interface) listenOut(i int) {
 	runtime.LockOSThread()
 
-	var li *udp.Conn
+	var li udp.Conn
 	// TODO clean this up with a coherent interface for each outside connection
 	if i > 0 {
 		li = f.writers[i]

lighthouse.go

@@ -39,7 +39,7 @@ type LightHouse struct {
 	myVpnIp      iputil.VpnIp
 	myVpnZeros   iputil.VpnIp
 	myVpnNet     *net.IPNet
-	punchConn    *udp.Conn
+	punchConn    udp.Conn
 	punchy       *Punchy
 
 	// Local cache of answers from light houses
@@ -84,7 +84,7 @@ type LightHouse struct {
 
 // NewLightHouseFromConfig will build a Lighthouse struct from the values provided in the config object
 // addrMap should be nil unless this is during a config reload
-func NewLightHouseFromConfig(ctx context.Context, l *logrus.Logger, c *config.C, myVpnNet *net.IPNet, pc *udp.Conn, p *Punchy) (*LightHouse, error) {
+func NewLightHouseFromConfig(ctx context.Context, l *logrus.Logger, c *config.C, myVpnNet *net.IPNet, pc udp.Conn, p *Punchy) (*LightHouse, error) {
 	amLighthouse := c.GetBool("lighthouse.am_lighthouse", false)
 	nebulaPort := uint32(c.GetInt("listen.port", 0))
 	if amLighthouse && nebulaPort == 0 {

main.go

@@ -147,7 +147,7 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 	}
 
 	// set up our UDP listener
-	udpConns := make([]*udp.Conn, routines)
+	udpConns := make([]udp.Conn, routines)
 	port := c.GetInt("listen.port", 0)
 
 	if !configTest {

udp/conn.go

@@ -1,6 +1,7 @@
 package udp
 
 import (
+	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/firewall"
 	"github.com/slackhq/nebula/header"
 )
@@ -18,3 +19,29 @@ type EncReader func(
 	q int,
 	localCache firewall.ConntrackCache,
 )
+
+type Conn interface {
+	Rebind() error
+	LocalAddr() (*Addr, error)
+	ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall.ConntrackCacheTicker, q int)
+	WriteTo(b []byte, addr *Addr) error
+	ReloadConfig(c *config.C)
+}
+
+type NoopConn struct{}
+
+func (NoopConn) Rebind() error {
+	return nil
+}
+func (NoopConn) LocalAddr() (*Addr, error) {
+	return nil, nil
+}
+func (NoopConn) ListenOut(_ EncReader, _ LightHouseHandlerFunc, _ *firewall.ConntrackCacheTicker, _ int) {
+	return
+}
+func (NoopConn) WriteTo(_ []byte, _ *Addr) error {
+	return nil
+}
+func (NoopConn) ReloadConfig(_ *config.C) {
+	return
+}

udp/udp_android.go

@@ -34,6 +34,6 @@ func NewListenConfig(multi bool) net.ListenConfig {
 	}
 }
 
-func (u *Conn) Rebind() error {
+func (u *GenericConn) Rebind() error {
 	return nil
 }

udp/udp_darwin.go

@@ -37,7 +37,7 @@ func NewListenConfig(multi bool) net.ListenConfig {
 	}
 }
 
-func (u *Conn) Rebind() error {
+func (u *GenericConn) Rebind() error {
 	file, err := u.File()
 	if err != nil {
 		return err

udp/udp_freebsd.go

@@ -36,6 +36,6 @@ func NewListenConfig(multi bool) net.ListenConfig {
 	}
 }
 
-func (u *Conn) Rebind() error {
+func (u *GenericConn) Rebind() error {
 	return nil
 }

udp/udp_generic.go

@@ -18,30 +18,30 @@ import (
 	"github.com/slackhq/nebula/header"
 )
 
-type Conn struct {
+type GenericConn struct {
 	*net.UDPConn
 	l *logrus.Logger
 }
 
-func NewListener(l *logrus.Logger, ip net.IP, port int, multi bool, batch int) (*Conn, error) {
+func NewListener(l *logrus.Logger, ip net.IP, port int, multi bool, batch int) (Conn, error) {
 	lc := NewListenConfig(multi)
 	pc, err := lc.ListenPacket(context.TODO(), "udp", net.JoinHostPort(ip.String(), fmt.Sprintf("%v", port)))
 	if err != nil {
 		return nil, err
 	}
 	if uc, ok := pc.(*net.UDPConn); ok {
-		return &Conn{UDPConn: uc, l: l}, nil
+		return &GenericConn{UDPConn: uc, l: l}, nil
 	}
 	return nil, fmt.Errorf("Unexpected PacketConn: %T %#v", pc, pc)
 }
 
-func (uc *Conn) WriteTo(b []byte, addr *Addr) error {
+func (u *GenericConn) WriteTo(b []byte, addr *Addr) error {
-	_, err := uc.UDPConn.WriteToUDP(b, &net.UDPAddr{IP: addr.IP, Port: int(addr.Port)})
+	_, err := u.UDPConn.WriteToUDP(b, &net.UDPAddr{IP: addr.IP, Port: int(addr.Port)})
 	return err
 }
 
-func (uc *Conn) LocalAddr() (*Addr, error) {
+func (u *GenericConn) LocalAddr() (*Addr, error) {
-	a := uc.UDPConn.LocalAddr()
+	a := u.UDPConn.LocalAddr()
 
 	switch v := a.(type) {
 	case *net.UDPAddr:
@@ -55,11 +55,11 @@ func (uc *Conn) LocalAddr() (*Addr, error) {
 	}
 }
 
-func (u *Conn) ReloadConfig(c *config.C) {
+func (u *GenericConn) ReloadConfig(c *config.C) {
 	// TODO
 }
 
-func NewUDPStatsEmitter(udpConns []*Conn) func() {
+func NewUDPStatsEmitter(udpConns []Conn) func() {
 	// No UDP stats for non-linux
 	return func() {}
 }
@@ -68,7 +68,7 @@ type rawMessage struct {
 	Len uint32
 }
 
-func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall.ConntrackCacheTicker, q int) {
+func (u *GenericConn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall.ConntrackCacheTicker, q int) {
 	plaintext := make([]byte, MTU)
 	buffer := make([]byte, MTU)
 	h := &header.H{}

udp/udp_linux.go

@@ -20,7 +20,7 @@ import (
 
 //TODO: make it support reload as best you can!
 
-type Conn struct {
+type StdConn struct {
 	sysFd int
 	l     *logrus.Logger
 	batch int
@@ -45,7 +45,7 @@ const (
 
 type _SK_MEMINFO [_SK_MEMINFO_VARS]uint32
 
-func NewListener(l *logrus.Logger, ip net.IP, port int, multi bool, batch int) (*Conn, error) {
+func NewListener(l *logrus.Logger, ip net.IP, port int, multi bool, batch int) (Conn, error) {
 	syscall.ForkLock.RLock()
 	fd, err := unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, unix.IPPROTO_UDP)
 	if err == nil {
@@ -77,30 +77,30 @@ func NewListener(l *logrus.Logger, ip net.IP, port int, multi bool, batch int) (
 	//v, err := unix.GetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_INCOMING_CPU)
 	//l.Println(v, err)
 
-	return &Conn{sysFd: fd, l: l, batch: batch}, err
+	return &StdConn{sysFd: fd, l: l, batch: batch}, err
 }
 
-func (u *Conn) Rebind() error {
+func (u *StdConn) Rebind() error {
 	return nil
 }
 
-func (u *Conn) SetRecvBuffer(n int) error {
+func (u *StdConn) SetRecvBuffer(n int) error {
 	return unix.SetsockoptInt(u.sysFd, unix.SOL_SOCKET, unix.SO_RCVBUFFORCE, n)
 }
 
-func (u *Conn) SetSendBuffer(n int) error {
+func (u *StdConn) SetSendBuffer(n int) error {
 	return unix.SetsockoptInt(u.sysFd, unix.SOL_SOCKET, unix.SO_SNDBUFFORCE, n)
 }
 
-func (u *Conn) GetRecvBuffer() (int, error) {
+func (u *StdConn) GetRecvBuffer() (int, error) {
 	return unix.GetsockoptInt(int(u.sysFd), unix.SOL_SOCKET, unix.SO_RCVBUF)
 }
 
-func (u *Conn) GetSendBuffer() (int, error) {
+func (u *StdConn) GetSendBuffer() (int, error) {
 	return unix.GetsockoptInt(int(u.sysFd), unix.SOL_SOCKET, unix.SO_SNDBUF)
 }
 
-func (u *Conn) LocalAddr() (*Addr, error) {
+func (u *StdConn) LocalAddr() (*Addr, error) {
 	sa, err := unix.Getsockname(u.sysFd)
 	if err != nil {
 		return nil, err
@@ -119,7 +119,7 @@ func (u *Conn) LocalAddr() (*Addr, error) {
 	return addr, nil
 }
 
-func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall.ConntrackCacheTicker, q int) {
+func (u *StdConn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall.ConntrackCacheTicker, q int) {
 	plaintext := make([]byte, MTU)
 	h := &header.H{}
 	fwPacket := &firewall.Packet{}
@@ -150,7 +150,7 @@ func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall
 	}
 }
 
-func (u *Conn) ReadSingle(msgs []rawMessage) (int, error) {
+func (u *StdConn) ReadSingle(msgs []rawMessage) (int, error) {
 	for {
 		n, _, err := unix.Syscall6(
 			unix.SYS_RECVMSG,
@@ -171,7 +171,7 @@ func (u *Conn) ReadSingle(msgs []rawMessage) (int, error) {
 	}
 }
 
-func (u *Conn) ReadMulti(msgs []rawMessage) (int, error) {
+func (u *StdConn) ReadMulti(msgs []rawMessage) (int, error) {
 	for {
 		n, _, err := unix.Syscall6(
 			unix.SYS_RECVMMSG,
@@ -191,7 +191,7 @@ func (u *Conn) ReadMulti(msgs []rawMessage) (int, error) {
 	}
 }
 
-func (u *Conn) WriteTo(b []byte, addr *Addr) error {
+func (u *StdConn) WriteTo(b []byte, addr *Addr) error {
 
 	var rsa unix.RawSockaddrInet6
 	rsa.Family = unix.AF_INET6
@@ -221,7 +221,7 @@ func (u *Conn) WriteTo(b []byte, addr *Addr) error {
 	}
 }
 
-func (u *Conn) ReloadConfig(c *config.C) {
+func (u *StdConn) ReloadConfig(c *config.C) {
 	b := c.GetInt("listen.read_buffer", 0)
 	if b > 0 {
 		err := u.SetRecvBuffer(b)
@@ -253,7 +253,7 @@ func (u *Conn) ReloadConfig(c *config.C) {
 	}
 }
 
-func (u *Conn) getMemInfo(meminfo *_SK_MEMINFO) error {
+func (u *StdConn) getMemInfo(meminfo *_SK_MEMINFO) error {
 	var vallen uint32 = 4 * _SK_MEMINFO_VARS
 	_, _, err := unix.Syscall6(unix.SYS_GETSOCKOPT, uintptr(u.sysFd), uintptr(unix.SOL_SOCKET), uintptr(unix.SO_MEMINFO), uintptr(unsafe.Pointer(meminfo)), uintptr(unsafe.Pointer(&vallen)), 0)
 	if err != 0 {
@@ -262,11 +262,11 @@ func (u *Conn) getMemInfo(meminfo *_SK_MEMINFO) error {
 	return nil
 }
 
-func NewUDPStatsEmitter(udpConns []*Conn) func() {
+func NewUDPStatsEmitter(udpConns []Conn) func() {
 	// Check if our kernel supports SO_MEMINFO before registering the gauges
 	var udpGauges [][_SK_MEMINFO_VARS]metrics.Gauge
 	var meminfo _SK_MEMINFO
-	if err := udpConns[0].getMemInfo(&meminfo); err == nil {
+	if err := udpConns[0].(*StdConn).getMemInfo(&meminfo); err == nil {
 		udpGauges = make([][_SK_MEMINFO_VARS]metrics.Gauge, len(udpConns))
 		for i := range udpConns {
 			udpGauges[i] = [_SK_MEMINFO_VARS]metrics.Gauge{
@@ -285,7 +285,7 @@ func NewUDPStatsEmitter(udpConns []*Conn) func() {
 
 	return func() {
 		for i, gauges := range udpGauges {
-			if err := udpConns[i].getMemInfo(&meminfo); err == nil {
+			if err := udpConns[i].(*StdConn).getMemInfo(&meminfo); err == nil {
 				for j := 0; j < _SK_MEMINFO_VARS; j++ {
 					gauges[j].Update(int64(meminfo[j]))
 				}

udp/udp_linux_32.go

@@ -30,7 +30,7 @@ type rawMessage struct {
 	Len uint32
 }
 
-func (u *Conn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
+func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
 	msgs := make([]rawMessage, n)
 	buffers := make([][]byte, n)
 	names := make([][]byte, n)

udp/udp_linux_64.go

@@ -33,7 +33,7 @@ type rawMessage struct {
 	Pad0 [4]byte
 }
 
-func (u *Conn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
+func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
 	msgs := make([]rawMessage, n)
 	buffers := make([][]byte, n)
 	names := make([][]byte, n)

udp/udp_tester.go

@@ -36,7 +36,7 @@ func (u *Packet) Copy() *Packet {
 	return n
 }
 
-type Conn struct {
+type TesterConn struct {
 	Addr *Addr
 
 	RxPackets chan *Packet // Packets to receive into nebula
@@ -45,8 +45,8 @@ type Conn struct {
 	l *logrus.Logger
 }
 
-func NewListener(l *logrus.Logger, ip net.IP, port int, _ bool, _ int) (*Conn, error) {
+func NewListener(l *logrus.Logger, ip net.IP, port int, _ bool, _ int) (Conn, error) {
-	return &Conn{
+	return &TesterConn{
 		Addr:      &Addr{ip, uint16(port)},
 		RxPackets: make(chan *Packet, 10),
 		TxPackets: make(chan *Packet, 10),
@@ -57,7 +57,7 @@ func NewListener(l *logrus.Logger, ip net.IP, port int, _ bool, _ int) (*Conn, e
 // Send will place a UdpPacket onto the receive queue for nebula to consume
 // this is an encrypted packet or a handshake message in most cases
 // packets were transmitted from another nebula node, you can send them with Tun.Send
-func (u *Conn) Send(packet *Packet) {
+func (u *TesterConn) Send(packet *Packet) {
 	h := &header.H{}
 	if err := h.Parse(packet.Data); err != nil {
 		panic(err)
@@ -74,7 +74,7 @@ func (u *Conn) Send(packet *Packet) {
 // Get will pull a UdpPacket from the transmit queue
 // nebula meant to send this message on the network, it will be encrypted
 // packets were ingested from the tun side (in most cases), you can send them with Tun.Send
-func (u *Conn) Get(block bool) *Packet {
+func (u *TesterConn) Get(block bool) *Packet {
 	if block {
 		return <-u.TxPackets
 	}
@@ -91,7 +91,7 @@ func (u *Conn) Get(block bool) *Packet {
 // Below this is boilerplate implementation to make nebula actually work
 //********************************************************************************************************************//
 
-func (u *Conn) WriteTo(b []byte, addr *Addr) error {
+func (u *TesterConn) WriteTo(b []byte, addr *Addr) error {
 	p := &Packet{
 		Data:     make([]byte, len(b), len(b)),
 		FromIp:   make([]byte, 16),
@@ -108,7 +108,7 @@ func (u *Conn) WriteTo(b []byte, addr *Addr) error {
 	return nil
 }
 
-func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall.ConntrackCacheTicker, q int) {
+func (u *TesterConn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall.ConntrackCacheTicker, q int) {
 	plaintext := make([]byte, MTU)
 	h := &header.H{}
 	fwPacket := &firewall.Packet{}
@@ -126,17 +126,17 @@ func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall
 	}
 }
 
-func (u *Conn) ReloadConfig(*config.C) {}
+func (u *TesterConn) ReloadConfig(*config.C) {}
 
-func NewUDPStatsEmitter(_ []*Conn) func() {
+func NewUDPStatsEmitter(_ []Conn) func() {
 	// No UDP stats for non-linux
 	return func() {}
 }
 
-func (u *Conn) LocalAddr() (*Addr, error) {
+func (u *TesterConn) LocalAddr() (*Addr, error) {
 	return u.Addr, nil
 }
 
-func (u *Conn) Rebind() error {
+func (u *TesterConn) Rebind() error {
 	return nil
 }

udp/udp_windows.go

@@ -24,6 +24,6 @@ func NewListenConfig(multi bool) net.ListenConfig {
 	}
 }
 
-func (u *Conn) Rebind() error {
+func (u *GenericConn) Rebind() error {
 	return nil
 }