Chore: code style

adapter/outbound/direct.go

@@ -23,7 +23,7 @@ func (d *Direct) DialContext(ctx context.Context, metadata *C.Metadata, opts ...
 
 	tcpKeepAlive(c)
 
-	if !metadata.DstIP.IsValid() && c.RemoteAddr() != nil {
+	if !metadata.Resolved() && c.RemoteAddr() != nil {
 		if h, _, err := net.SplitHostPort(c.RemoteAddr().String()); err == nil {
 			metadata.DstIP = netip.MustParseAddr(h)
 		}

adapter/outbound/mitm.go

@@ -24,6 +24,7 @@ func (m *Mitm) DialContext(_ context.Context, metadata *C.Metadata, _ ...dialer.
 
 	_ = c.SetKeepAlive(true)
 	_ = c.SetKeepAlivePeriod(60 * time.Second)
+	_ = c.SetLinger(0)
 
 	metadata.Type = C.MITM
 

adapter/outbound/util.go

@@ -15,6 +15,7 @@ func tcpKeepAlive(c net.Conn) {
 	if tcp, ok := c.(*net.TCPConn); ok {
 		_ = tcp.SetKeepAlive(true)
 		_ = tcp.SetKeepAlivePeriod(30 * time.Second)
+		_ = tcp.SetLinger(0)
 	}
 }
 

adapter/outbound/vmess.go

@@ -116,7 +116,9 @@ func (v *Vmess) StreamConn(c net.Conn, metadata *C.Metadata) (net.Conn, error) {
 				wsOpts.TLSConfig.ServerName = host
 			}
 		} else {
+			if wsOpts.Headers.Get("Host") == "" {
 				wsOpts.Headers.Set("Host", convert.RandHost())
+			}
 			convert.SetUserAgent(wsOpts.Headers)
 		}
 		c, err = vmess.StreamWebsocketConn(c, wsOpts)

adapter/outboundgroup/util.go

@@ -48,5 +48,6 @@ func tcpKeepAlive(c net.Conn) {
 	if tcp, ok := c.(*net.TCPConn); ok {
 		_ = tcp.SetKeepAlive(true)
 		_ = tcp.SetKeepAlivePeriod(30 * time.Second)
+		_ = tcp.SetLinger(0)
 	}
 }

common/net/relay.go

@@ -4,8 +4,6 @@ import (
 	"io"
 	"net"
 	"time"
-
-	"github.com/Dreamacro/clash/common/pool"
 )
 
 // Relay copies between left and right bidirectionally.
@@ -16,18 +14,14 @@ func Relay(leftConn, rightConn net.Conn) {
 	tcpKeepAlive(rightConn)
 
 	go func() {
-		buf := pool.Get(pool.RelayBufferSize)
 		// Wrapping to avoid using *net.TCPConn.(ReadFrom)
 		// See also https://github.com/Dreamacro/clash/pull/1209
-		_, err := io.CopyBuffer(WriteOnlyWriter{Writer: leftConn}, ReadOnlyReader{Reader: rightConn}, buf)
+		_, err := io.Copy(WriteOnlyWriter{Writer: leftConn}, ReadOnlyReader{Reader: rightConn})
-		_ = pool.Put(buf)
 		_ = leftConn.SetReadDeadline(time.Now())
 		ch <- err
 	}()
 
-	buf := pool.Get(pool.RelayBufferSize)
+	_, _ = io.Copy(WriteOnlyWriter{Writer: rightConn}, ReadOnlyReader{Reader: leftConn})
-	_, _ = io.CopyBuffer(WriteOnlyWriter{Writer: rightConn}, ReadOnlyReader{Reader: leftConn}, buf)
-	_ = pool.Put(buf)
 	_ = rightConn.SetReadDeadline(time.Now())
 	<-ch
 }

listener/tproxy/packet.go

@@ -24,15 +24,15 @@ func (c *packet) WriteBack(b []byte, addr net.Addr) (n int, err error) {
 		return
 	}
 	n, err = tc.Write(b)
-	tc.Close()
+	_ = tc.Close()
 	return
 }
 
 // LocalAddr returns the source IP/Port of UDP Packet
 func (c *packet) LocalAddr() net.Addr {
-	return &net.UDPAddr{IP: c.lAddr.Addr().AsSlice(), Port: int(c.lAddr.Port()), Zone: c.lAddr.Addr().Zone()}
+	return net.UDPAddrFromAddrPort(c.lAddr)
 }
 
 func (c *packet) Drop() {
-	pool.Put(c.buf)
+	_ = pool.Put(c.buf)
 }

listener/tproxy/tcp.go

@@ -32,7 +32,7 @@ func (l *Listener) Close() error {
 
 func (l *Listener) handleTProxy(conn net.Conn, in chan<- C.ConnContext) {
 	target := socks5.ParseAddrToSocksAddr(conn.LocalAddr())
-	conn.(*net.TCPConn).SetKeepAlive(true)
+	_ = conn.(*net.TCPConn).SetKeepAlive(true)
 	in <- inbound.NewSocket(target, conn, C.TPROXY)
 }
 

listener/tproxy/udp.go

@@ -61,7 +61,7 @@ func NewUDP(addr string, in chan<- *inbound.PacketAdapter) (*UDPListener, error)
 			buf := pool.Get(pool.UDPBufferSize)
 			n, oobn, _, lAddr, err := c.ReadMsgUDPAddrPort(buf, oob)
 			if err != nil {
-				pool.Put(buf)
+				_ = pool.Put(buf)
 				if rl.closed {
 					break
 				}

listener/tun/ipstack/gvisor/adapter/adapter.go

@@ -2,23 +2,15 @@ package adapter
 
 import (
 	"net"
-
-	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
 
 // TCPConn implements the net.Conn interface.
 type TCPConn interface {
 	net.Conn
-
-	// ID returns the transport endpoint id of TCPConn.
-	ID() *stack.TransportEndpointID
 }
 
 // UDPConn implements net.Conn and net.PacketConn.
 type UDPConn interface {
 	net.Conn
 	net.PacketConn
-
-	// ID returns the transport endpoint id of UDPConn.
-	ID() *stack.TransportEndpointID
 }

listener/tun/ipstack/gvisor/handler.go

@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"github.com/Dreamacro/clash/adapter/inbound"
-	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/common/pool"
 	C "github.com/Dreamacro/clash/constant"
 	D "github.com/Dreamacro/clash/listener/tun/ipstack/commons"
@@ -27,15 +26,7 @@ type gvHandler struct {
 }
 
 func (gh *gvHandler) HandleTCP(tunConn adapter.TCPConn) {
-	id := tunConn.ID()
+	rAddrPort := tunConn.LocalAddr().(*net.TCPAddr).AddrPort()
-
-	rAddr := &net.UDPAddr{
-		IP:   net.IP(id.LocalAddress),
-		Port: int(id.LocalPort),
-		Zone: "",
-	}
-
-	rAddrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), id.LocalPort)
 
 	if D.ShouldHijackDns(gh.dnsHijack, rAddrPort, "tcp") {
 		go func() {
@@ -43,8 +34,8 @@ func (gh *gvHandler) HandleTCP(tunConn adapter.TCPConn) {
 
 			buf := pool.Get(pool.UDPBufferSize)
 			defer func() {
-				_ = pool.Put(buf)
 				_ = tunConn.Close()
+				_ = pool.Put(buf)
 			}()
 
 			for {
@@ -78,26 +69,18 @@ func (gh *gvHandler) HandleTCP(tunConn adapter.TCPConn) {
 		return
 	}
 
-	gh.tcpIn <- inbound.NewSocket(socks5.ParseAddrToSocksAddr(rAddr), tunConn, C.TUN)
+	gh.tcpIn <- inbound.NewSocket(socks5.AddrFromStdAddrPort(rAddrPort), tunConn, C.TUN)
 }
 
 func (gh *gvHandler) HandleUDP(tunConn adapter.UDPConn) {
-	id := tunConn.ID()
+	rAddrPort := tunConn.LocalAddr().(*net.UDPAddr).AddrPort()
-
-	rAddr := &net.UDPAddr{
-		IP:   net.IP(id.LocalAddress),
-		Port: int(id.LocalPort),
-		Zone: "",
-	}
-
-	rAddrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), id.LocalPort)
 
 	if rAddrPort.Addr() == gh.gateway {
 		_ = tunConn.Close()
 		return
 	}
 
-	target := socks5.ParseAddrToSocksAddr(rAddr)
+	target := socks5.AddrFromStdAddrPort(rAddrPort)
 
 	go func() {
 		for {
@@ -109,22 +92,20 @@ func (gh *gvHandler) HandleUDP(tunConn adapter.UDPConn) {
 				break
 			}
 
-			payload := buf[:n]
-
 			if D.ShouldHijackDns(gh.dnsHijack, rAddrPort, "udp") {
 				go func() {
 					defer func() {
 						_ = pool.Put(buf)
 					}()
 
-					msg, err1 := D.RelayDnsPacket(payload)
+					msg, err1 := D.RelayDnsPacket(buf[:n])
 					if err1 != nil {
 						return
 					}
 
 					_, _ = tunConn.WriteTo(msg, addr)
 
-					log.Debugln("[TUN] hijack dns udp: %s", rAddr.String())
+					log.Debugln("[TUN] hijack dns udp: %s", rAddrPort.String())
 				}()
 
 				continue
@@ -133,12 +114,14 @@ func (gh *gvHandler) HandleUDP(tunConn adapter.UDPConn) {
 			gvPacket := &packet{
 				pc:      tunConn,
 				rAddr:   addr,
-				payload: payload,
+				payload: buf,
+				offset:  n,
 			}
 
 			select {
 			case gh.udpIn <- inbound.NewPacket(target, gvPacket, C.TUN):
 			default:
+				gvPacket.Drop()
 			}
 		}
 	}()

listener/tun/ipstack/gvisor/tcp.go

@@ -70,7 +70,6 @@ func withTCPHandler(handle adapter.TCPHandleFunc) option.Option {
 
 			conn := &tcpConn{
 				TCPConn: gonet.NewTCPConn(&wq, ep),
-				id:      id,
 			}
 			handle(conn)
 		})
@@ -113,9 +112,4 @@ func setSocketOptions(s *stack.Stack, ep tcpip.Endpoint) tcpip.Error {
 
 type tcpConn struct {
 	*gonet.TCPConn
-	id stack.TransportEndpointID
-}
-
-func (c *tcpConn) ID() *stack.TransportEndpointID {
-	return &c.id
 }

listener/tun/ipstack/gvisor/udp.go

@@ -29,7 +29,6 @@ func withUDPHandler(handle adapter.UDPHandleFunc) option.Option {
 
 			conn := &udpConn{
 				UDPConn: gonet.NewUDPConn(s, &wq, ep),
-				id:      id,
 			}
 			handle(conn)
 		})
@@ -40,21 +39,17 @@ func withUDPHandler(handle adapter.UDPHandleFunc) option.Option {
 
 type udpConn struct {
 	*gonet.UDPConn
-	id stack.TransportEndpointID
-}
-
-func (c *udpConn) ID() *stack.TransportEndpointID {
-	return &c.id
 }
 
 type packet struct {
 	pc      adapter.UDPConn
 	rAddr   net.Addr
 	payload []byte
+	offset  int
 }
 
 func (c *packet) Data() []byte {
-	return c.payload
+	return c.payload[:c.offset]
 }
 
 // WriteBack write UDP packet with source(ip, port) = `addr`

listener/tun/ipstack/system/mars/nat/nat.go

@@ -5,7 +5,6 @@ import (
 	"net"
 	"net/netip"
 
-	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/listener/tun/ipstack/system/mars/tcpip"
 )
 
@@ -22,7 +21,7 @@ func Start(device io.ReadWriter, gateway, portal, broadcast netip.Addr) (*TCP, *
 	tab := newTable()
 	udp := &UDP{
 		device: device,
-		buf:    [pool.UDPBufferSize]byte{},
+		buf:    [0xffff]byte{},
 	}
 	tcp := &TCP{
 		listener: listener,
@@ -38,7 +37,7 @@ func Start(device io.ReadWriter, gateway, portal, broadcast netip.Addr) (*TCP, *
 			_ = udp.Close()
 		}()
 
-		buf := make([]byte, pool.RelayBufferSize)
+		buf := make([]byte, 0xffff)
 
 		for {
 			n, err := device.Read(buf)
@@ -152,7 +151,7 @@ func Start(device io.ReadWriter, gateway, portal, broadcast netip.Addr) (*TCP, *
 					continue
 				}
 
-				udp.handleUDPPacket(ip, u)
+				go udp.handleUDPPacket(ip, u)
 			case tcpip.ICMP:
 				i := tcpip.ICMPPacket(ip.Payload())
 

listener/tun/ipstack/system/mars/nat/table.go

@@ -2,8 +2,11 @@ package nat
 
 import (
 	"net/netip"
+	"sync"
 
 	"github.com/Dreamacro/clash/common/generics/list"
+
+	"golang.org/x/exp/maps"
 )
 
 const (
@@ -27,6 +30,7 @@ type table struct {
 	tuples    map[tuple]*list.Element[*binding]
 	ports     [portLength]*list.Element[*binding]
 	available *list.List[*binding]
+	mux       sync.Mutex
 }
 
 func (t *table) tupleOf(port uint16) tuple {
@@ -43,10 +47,13 @@ func (t *table) tupleOf(port uint16) tuple {
 }
 
 func (t *table) portOf(tuple tuple) uint16 {
+	t.mux.Lock()
 	elm := t.tuples[tuple]
 	if elm == nil {
+		t.mux.Unlock()
 		return 0
 	}
+	t.mux.Unlock()
 
 	t.available.MoveToFront(elm)
 
@@ -54,18 +61,40 @@ func (t *table) portOf(tuple tuple) uint16 {
 }
 
 func (t *table) newConn(tuple tuple) uint16 {
-	elm := t.available.Back()
+	t.mux.Lock()
+	elm := t.availableConn()
 	b := elm.Value
-
-	delete(t.tuples, b.tuple)
 	t.tuples[tuple] = elm
 	b.tuple = tuple
+	t.mux.Unlock()
 
 	t.available.MoveToFront(elm)
 
 	return portBegin + b.offset
 }
 
+func (t *table) availableConn() *list.Element[*binding] {
+	elm := t.available.Back()
+	offset := elm.Value.offset
+	_, ok := t.tuples[t.ports[offset].Value.tuple]
+	if !ok {
+		if offset != 0 && offset%portLength == 0 { // resize
+			tuples := make(map[tuple]*list.Element[*binding], portLength)
+			maps.Copy(tuples, t.tuples)
+			t.tuples = tuples
+		}
+		return elm
+	}
+	t.available.MoveToFront(elm)
+	return t.availableConn()
+}
+
+func (t *table) closeConn(tuple tuple) {
+	t.mux.Lock()
+	delete(t.tuples, tuple)
+	t.mux.Unlock()
+}
+
 func newTable() *table {
 	result := &table{
 		tuples:    make(map[tuple]*list.Element[*binding], portLength),

listener/tun/ipstack/system/mars/nat/tcp.go

@@ -16,6 +16,8 @@ type conn struct {
 	net.Conn
 
 	tuple tuple
+
+	close func()
 }
 
 func (t *TCP) Accept() (net.Conn, error) {
@@ -24,9 +26,9 @@ func (t *TCP) Accept() (net.Conn, error) {
 		return nil, err
 	}
 
-	addr := c.RemoteAddr().(*net.TCPAddr)
+	addr := c.RemoteAddr().(*net.TCPAddr).AddrPort()
-	tup := t.table.tupleOf(uint16(addr.Port))
+	tup := t.table.tupleOf(addr.Port())
-	if !addr.IP.Equal(t.portal.AsSlice()) || tup == zeroTuple {
+	if addr.Addr() != t.portal || tup == zeroTuple {
 		_ = c.Close()
 
 		return nil, net.InvalidAddrError("unknown remote addr")
@@ -34,9 +36,14 @@ func (t *TCP) Accept() (net.Conn, error) {
 
 	addition(c)
 
+	_ = c.SetLinger(0)
+
 	return &conn{
 		Conn:  c,
 		tuple: tup,
+		close: func() {
+			t.table.closeConn(tup)
+		},
 	}, nil
 }
 
@@ -52,16 +59,15 @@ func (t *TCP) SetDeadline(time time.Time) error {
 	return t.listener.SetDeadline(time)
 }
 
+func (c *conn) Close() error {
+	c.close()
+	return c.Conn.Close()
+}
+
 func (c *conn) LocalAddr() net.Addr {
-	return &net.TCPAddr{
+	return net.TCPAddrFromAddrPort(c.tuple.SourceAddr)
-		IP:   c.tuple.SourceAddr.Addr().AsSlice(),
-		Port: int(c.tuple.SourceAddr.Port()),
-	}
 }
 
 func (c *conn) RemoteAddr() net.Addr {
-	return &net.TCPAddr{
+	return net.TCPAddrFromAddrPort(c.tuple.DestinationAddr)
-		IP:   c.tuple.DestinationAddr.Addr().AsSlice(),
-		Port: int(c.tuple.DestinationAddr.Port()),
-	}
 }

listener/tun/ipstack/system/mars/nat/udp.go

@@ -7,8 +7,6 @@ import (
 	"net/netip"
 	"sync"
 
-	"github.com/Dreamacro/clash/common/nnip"
-	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/listener/tun/ipstack/system/mars/tcpip"
 )
 
@@ -16,8 +14,8 @@ type call struct {
 	cond        *sync.Cond
 	buf         []byte
 	n           int
-	source      net.Addr
+	source      netip.AddrPort
-	destination net.Addr
+	destination netip.AddrPort
 }
 
 type UDP struct {
@@ -26,10 +24,10 @@ type UDP struct {
 	queueLock sync.Mutex
 	queue     []*call
 	bufLock   sync.Mutex
-	buf       [pool.UDPBufferSize]byte
+	buf       [0xffff]byte
 }
 
-func (u *UDP) ReadFrom(buf []byte) (int, net.Addr, net.Addr, error) {
+func (u *UDP) ReadFrom(buf []byte) (int, netip.AddrPort, netip.AddrPort, error) {
 	u.queueLock.Lock()
 	defer u.queueLock.Unlock()
 
@@ -38,8 +36,8 @@ func (u *UDP) ReadFrom(buf []byte) (int, net.Addr, net.Addr, error) {
 			cond:        sync.NewCond(&u.queueLock),
 			buf:         buf,
 			n:           -1,
-			source:      nil,
+			source:      netip.AddrPort{},
-			destination: nil,
+			destination: netip.AddrPort{},
 		}
 
 		u.queue = append(u.queue, c)
@@ -51,10 +49,10 @@ func (u *UDP) ReadFrom(buf []byte) (int, net.Addr, net.Addr, error) {
 		}
 	}
 
-	return -1, nil, nil, net.ErrClosed
+	return -1, netip.AddrPort{}, netip.AddrPort{}, net.ErrClosed
 }
 
-func (u *UDP) WriteTo(buf []byte, local net.Addr, remote net.Addr) (int, error) {
+func (u *UDP) WriteTo(buf []byte, local netip.AddrPort, remote netip.AddrPort) (int, error) {
 	if u.closed {
 		return 0, net.ErrClosed
 	}
@@ -66,16 +64,7 @@ func (u *UDP) WriteTo(buf []byte, local net.Addr, remote net.Addr) (int, error)
 		return 0, net.InvalidAddrError("invalid ip version")
 	}
 
-	srcAddr, srcOk := local.(*net.UDPAddr)
+	if !local.Addr().Is4() || !remote.Addr().Is4() {
-	dstAddr, dstOk := remote.(*net.UDPAddr)
-	if !srcOk || !dstOk {
-		return 0, net.InvalidAddrError("invalid addr")
-	}
-
-	srcAddrPort := netip.AddrPortFrom(nnip.IpToAddr(srcAddr.IP), uint16(srcAddr.Port))
-	dstAddrPort := netip.AddrPortFrom(nnip.IpToAddr(dstAddr.IP), uint16(dstAddr.Port))
-
-	if !srcAddrPort.Addr().Is4() || !dstAddrPort.Addr().Is4() {
 		return 0, net.InvalidAddrError("invalid ip version")
 	}
 
@@ -89,13 +78,13 @@ func (u *UDP) WriteTo(buf []byte, local net.Addr, remote net.Addr) (int, error)
 	ip.SetFragmentOffset(0)
 	ip.SetTimeToLive(64)
 	ip.SetProtocol(tcpip.UDP)
-	ip.SetSourceIP(srcAddrPort.Addr())
+	ip.SetSourceIP(local.Addr())
-	ip.SetDestinationIP(dstAddrPort.Addr())
+	ip.SetDestinationIP(remote.Addr())
 
 	udp := tcpip.UDPPacket(ip.Payload())
 	udp.SetLength(tcpip.UDPHeaderSize + uint16(len(buf)))
-	udp.SetSourcePort(srcAddrPort.Port())
+	udp.SetSourcePort(local.Port())
-	udp.SetDestinationPort(dstAddrPort.Port())
+	udp.SetDestinationPort(remote.Port())
 	copy(udp.Payload(), buf)
 
 	ip.ResetChecksum()
@@ -131,14 +120,8 @@ func (u *UDP) handleUDPPacket(ip tcpip.IP, pkt tcpip.UDPPacket) {
 	u.queueLock.Unlock()
 
 	if c != nil {
-		c.source = &net.UDPAddr{
+		c.source = netip.AddrPortFrom(ip.SourceIP(), pkt.SourcePort())
-			IP:   ip.SourceIP().AsSlice(),
+		c.destination = netip.AddrPortFrom(ip.DestinationIP(), pkt.DestinationPort())
-			Port: int(pkt.SourcePort()),
-		}
-		c.destination = &net.UDPAddr{
-			IP:   ip.DestinationIP().AsSlice(),
-			Port: int(pkt.DestinationPort()),
-		}
 		c.n = copy(c.buf, pkt.Payload())
 		c.cond.Signal()
 	}

listener/tun/ipstack/system/stack.go

@@ -81,26 +81,23 @@ func New(device device.Device, dnsHijack []C.DNSUrl, tunAddress netip.Prefix, tc
 				continue
 			}
 
-			lAddr := conn.LocalAddr().(*net.TCPAddr)
+			lAddr := conn.LocalAddr().(*net.TCPAddr).AddrPort()
-			rAddr := conn.RemoteAddr().(*net.TCPAddr)
+			rAddr := conn.RemoteAddr().(*net.TCPAddr).AddrPort()
 
-			lAddrPort := netip.AddrPortFrom(nnip.IpToAddr(lAddr.IP), uint16(lAddr.Port))
+			if rAddr.Addr().IsLoopback() {
-			rAddrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), uint16(rAddr.Port))
-
-			if rAddrPort.Addr().IsLoopback() {
 				_ = conn.Close()
 
 				continue
 			}
 
-			if D.ShouldHijackDns(dnsAddr, rAddrPort, "tcp") {
+			if D.ShouldHijackDns(dnsAddr, rAddr, "tcp") {
 				go func() {
-					log.Debugln("[TUN] hijack dns tcp: %s", rAddrPort.String())
+					log.Debugln("[TUN] hijack dns tcp: %s", rAddr.String())
 
 					buf := pool.Get(pool.UDPBufferSize)
 					defer func() {
-						_ = pool.Put(buf)
 						_ = conn.Close()
+						_ = pool.Put(buf)
 					}()
 
 					for {
@@ -137,10 +134,10 @@ func New(device device.Device, dnsHijack []C.DNSUrl, tunAddress netip.Prefix, tc
 			metadata := &C.Metadata{
 				NetWork:  C.TCP,
 				Type:     C.TUN,
-				SrcIP:    lAddrPort.Addr(),
+				SrcIP:    lAddr.Addr(),
-				DstIP:    rAddrPort.Addr(),
+				DstIP:    rAddr.Addr(),
-				SrcPort:  strconv.Itoa(lAddr.Port),
+				SrcPort:  strconv.FormatUint(uint64(lAddr.Port()), 10),
-				DstPort:  strconv.Itoa(rAddr.Port),
+				DstPort:  strconv.FormatUint(uint64(rAddr.Port()), 10),
 				AddrType: C.AtypIPv4,
 				Host:     "",
 			}
@@ -159,37 +156,32 @@ func New(device device.Device, dnsHijack []C.DNSUrl, tunAddress netip.Prefix, tc
 		for !ipStack.closed {
 			buf := pool.Get(pool.UDPBufferSize)
 
-			n, lRAddr, rRAddr, err := stack.UDP().ReadFrom(buf)
+			n, lAddr, rAddr, err := stack.UDP().ReadFrom(buf)
 			if err != nil {
 				_ = pool.Put(buf)
 				break
 			}
 
-			raw := buf[:n]
+			if rAddr.Addr().IsLoopback() || rAddr.Addr() == gateway {
-			lAddr := lRAddr.(*net.UDPAddr)
-			rAddr := rRAddr.(*net.UDPAddr)
-
-			rAddrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), uint16(rAddr.Port))
-
-			if rAddrPort.Addr().IsLoopback() || rAddrPort.Addr() == gateway {
 				_ = pool.Put(buf)
 
 				continue
 			}
 
-			if D.ShouldHijackDns(dnsAddr, rAddrPort, "udp") {
+			if D.ShouldHijackDns(dnsAddr, rAddr, "udp") {
 				go func() {
-					msg, err := D.RelayDnsPacket(raw)
+					defer func() {
-					if err != nil {
 						_ = pool.Put(buf)
+					}()
+
+					msg, err := D.RelayDnsPacket(buf[:n])
+					if err != nil {
 						return
 					}
 
 					_, _ = stack.UDP().WriteTo(msg, rAddr, lAddr)
 
-					_ = pool.Put(buf)
+					log.Debugln("[TUN] hijack dns udp: %s", rAddr.String())
-
-					log.Debugln("[TUN] hijack dns udp: %s", rAddrPort.String())
 				}()
 
 				continue
@@ -197,18 +189,17 @@ func New(device device.Device, dnsHijack []C.DNSUrl, tunAddress netip.Prefix, tc
 
 			pkt := &packet{
 				local:  lAddr,
-				data:  raw,
+				data:   buf,
+				offset: n,
 				writeBack: func(b []byte, addr net.Addr) (int, error) {
 					return stack.UDP().WriteTo(b, rAddr, lAddr)
 				},
-				drop: func() {
-					_ = pool.Put(buf)
-				},
 			}
 
 			select {
-			case udpIn <- inbound.NewPacket(socks5.ParseAddrToSocksAddr(rAddr), pkt, C.TUN):
+			case udpIn <- inbound.NewPacket(socks5.AddrFromStdAddrPort(rAddr), pkt, C.TUN):
 			default:
+				pkt.Drop()
 			}
 		}
 

listener/tun/ipstack/system/udp.go

@@ -1,16 +1,21 @@
 package system
 
-import "net"
+import (
+	"net"
+	"net/netip"
+
+	"github.com/Dreamacro/clash/common/pool"
+)
 
 type packet struct {
-	local     *net.UDPAddr
+	local     netip.AddrPort
 	data      []byte
+	offset    int
 	writeBack func(b []byte, addr net.Addr) (int, error)
-	drop      func()
 }
 
 func (pkt *packet) Data() []byte {
-	return pkt.data
+	return pkt.data[:pkt.offset]
 }
 
 func (pkt *packet) WriteBack(b []byte, addr net.Addr) (n int, err error) {
@@ -18,9 +23,9 @@ func (pkt *packet) WriteBack(b []byte, addr net.Addr) (n int, err error) {
 }
 
 func (pkt *packet) Drop() {
-	pkt.drop()
+	_ = pool.Put(pkt.data)
 }
 
 func (pkt *packet) LocalAddr() net.Addr {
-	return pkt.local
+	return net.UDPAddrFromAddrPort(pkt.local)
 }

tunnel/connection.go

@@ -32,19 +32,21 @@ func handleUDPToRemote(packet C.UDPPacket, pc C.PacketConn, metadata *C.Metadata
 		return err
 	}
 	// reset timeout
-	pc.SetReadDeadline(time.Now().Add(udpTimeout))
+	_ = pc.SetReadDeadline(time.Now().Add(udpTimeout))
 
 	return nil
 }
 
 func handleUDPToLocal(packet C.UDPPacket, pc net.PacketConn, key string, fAddr net.Addr) {
 	buf := pool.Get(pool.UDPBufferSize)
-	defer pool.Put(buf)
+	defer func() {
-	defer natTable.Delete(key)
+		_ = pc.Close()
-	defer pc.Close()
+		natTable.Delete(key)
+		_ = pool.Put(buf)
+	}()
 
 	for {
-		pc.SetReadDeadline(time.Now().Add(udpTimeout))
+		_ = pc.SetReadDeadline(time.Now().Add(udpTimeout))
 		n, from, err := pc.ReadFrom(buf)
 		if err != nil {
 			return