chore: update proxy's udpConn when received a new packet

component/nat/proxy.go

@@ -0,0 +1,26 @@
+package nat
+
+import (
+	"net"
+
+	"github.com/Dreamacro/clash/common/atomic"
+	C "github.com/Dreamacro/clash/constant"
+)
+
+type writeBackProxy struct {
+	wb atomic.TypedValue[C.WriteBack]
+}
+
+func (w *writeBackProxy) WriteBack(b []byte, addr net.Addr) (n int, err error) {
+	return w.wb.Load().WriteBack(b, addr)
+}
+
+func (w *writeBackProxy) UpdateWriteBack(wb C.WriteBack) {
+	w.wb.Store(wb)
+}
+
+func NewWriteBackProxy(wb C.WriteBack) C.WriteBackProxy {
+	w := &writeBackProxy{}
+	w.UpdateWriteBack(wb)
+	return w
+}

component/nat/table.go

@@ -13,22 +13,24 @@ type Table struct {
 
 type Entry struct {
 	PacketConn      C.PacketConn
+	WriteBackProxy  C.WriteBackProxy
 	LocalUDPConnMap sync.Map
 }
 
-func (t *Table) Set(key string, e C.PacketConn) {
+func (t *Table) Set(key string, e C.PacketConn, w C.WriteBackProxy) {
 	t.mapping.Store(key, &Entry{
 		PacketConn:      e,
+		WriteBackProxy:  w,
 		LocalUDPConnMap: sync.Map{},
 	})
 }
 
-func (t *Table) Get(key string) C.PacketConn {
+func (t *Table) Get(key string) (C.PacketConn, C.WriteBackProxy) {
 	entry, exist := t.getEntry(key)
 	if !exist {
-		return nil
+		return nil, nil
 	}
-	return entry.PacketConn
+	return entry.PacketConn, entry.WriteBackProxy
 }
 
 func (t *Table) GetOrCreateLock(key string) (*sync.Cond, bool) {

constant/adapters.go

@@ -217,7 +217,7 @@ type UDPPacket interface {
 	// - variable source IP/Port is important to STUN
 	// - if addr is not provided, WriteBack will write out UDP packet with SourceIP/Port equals to original Target,
 	//   this is important when using Fake-IP.
-	WriteBack(b []byte, addr net.Addr) (n int, err error)
+	WriteBack
 
 	// Drop call after packet is used, could recycle buffer in this function.
 	Drop()
@@ -236,10 +236,19 @@ type PacketAdapter interface {
 	Metadata() *Metadata
 }
 
-type NatTable interface {
+type WriteBack interface {
-	Set(key string, e PacketConn)
+	WriteBack(b []byte, addr net.Addr) (n int, err error)
+}
 
-	Get(key string) PacketConn
+type WriteBackProxy interface {
+	WriteBack
+	UpdateWriteBack(wb WriteBack)
+}
+
+type NatTable interface {
+	Set(key string, e PacketConn, w WriteBackProxy)
+
+	Get(key string) (PacketConn, WriteBackProxy)
 
 	GetOrCreateLock(key string) (*sync.Cond, bool)
 

listener/shadowsocks/udp.go

@@ -58,7 +58,7 @@ func (l *UDPListener) LocalAddr() net.Addr {
 	return l.packetConn.LocalAddr()
 }
 
-func handleSocksUDP(pc net.PacketConn, in chan<- C.PacketAdapter, buf []byte, put func(), addr net.Addr) {
+func handleSocksUDP(pc net.PacketConn, in chan<- C.PacketAdapter, buf []byte, put func(), addr net.Addr, additions ...inbound.Addition) {
 	tgtAddr := socks5.SplitAddr(buf)
 	if tgtAddr == nil {
 		// Unresolved UDP packet, return buffer to the pool
@@ -77,7 +77,7 @@ func handleSocksUDP(pc net.PacketConn, in chan<- C.PacketAdapter, buf []byte, pu
 		put:     put,
 	}
 	select {
-	case in <- inbound.NewPacket(target, packet, C.SHADOWSOCKS):
+	case in <- inbound.NewPacket(target, packet, C.SHADOWSOCKS, additions...):
 	default:
 	}
 }

listener/shadowsocks/utils.go

@@ -38,7 +38,9 @@ func (c *packet) LocalAddr() net.Addr {
 func (c *packet) Drop() {
 	if c.put != nil {
 		c.put()
+		c.put = nil
 	}
+	c.payload = nil
 }
 
 func (c *packet) InAddr() net.Addr {

listener/socks/udp.go

@@ -4,7 +4,7 @@ import (
 	"net"
 
 	"github.com/Dreamacro/clash/adapter/inbound"
-	"github.com/Dreamacro/clash/common/pool"
+	N "github.com/Dreamacro/clash/common/net"
 	"github.com/Dreamacro/clash/common/sockopt"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/log"
@@ -53,36 +53,40 @@ func NewUDP(addr string, in chan<- C.PacketAdapter, additions ...inbound.Additio
 		packetConn: l,
 		addr:       addr,
 	}
+	conn := N.NewEnhancePacketConn(l)
 	go func() {
 		for {
-			buf := pool.Get(pool.UDPBufferSize)
+			data, put, remoteAddr, err := conn.WaitReadFrom()
-			n, remoteAddr, err := l.ReadFrom(buf)
 			if err != nil {
-				pool.Put(buf)
+				if put != nil {
+					put()
+				}
 				if sl.closed {
 					break
 				}
 				continue
 			}
-			handleSocksUDP(l, in, buf[:n], remoteAddr, additions...)
+			handleSocksUDP(l, in, data, put, remoteAddr, additions...)
 		}
 	}()
 
 	return sl, nil
 }
 
-func handleSocksUDP(pc net.PacketConn, in chan<- C.PacketAdapter, buf []byte, addr net.Addr, additions ...inbound.Addition) {
+func handleSocksUDP(pc net.PacketConn, in chan<- C.PacketAdapter, buf []byte, put func(), addr net.Addr, additions ...inbound.Addition) {
 	target, payload, err := socks5.DecodeUDPPacket(buf)
 	if err != nil {
 		// Unresolved UDP packet, return buffer to the pool
-		pool.Put(buf)
+		if put != nil {
+			put()
+		}
 		return
 	}
 	packet := &packet{
 		pc:      pc,
 		rAddr:   addr,
 		payload: payload,
-		bufRef:  buf,
+		put:     put,
 	}
 	select {
 	case in <- inbound.NewPacket(target, packet, C.SOCKS5, additions...):

listener/socks/utils.go

@@ -3,7 +3,6 @@ package socks
 import (
 	"net"
 
-	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/transport/socks5"
 )
 
@@ -11,7 +10,7 @@ type packet struct {
 	pc      net.PacketConn
 	rAddr   net.Addr
 	payload []byte
-	bufRef  []byte
+	put     func()
 }
 
 func (c *packet) Data() []byte {
@@ -33,7 +32,11 @@ func (c *packet) LocalAddr() net.Addr {
 }
 
 func (c *packet) Drop() {
-	pool.Put(c.bufRef)
+	if c.put != nil {
+		c.put()
+		c.put = nil
+	}
+	c.payload = nil
 }
 
 func (c *packet) InAddr() net.Addr {

listener/tproxy/packet.go

@@ -41,7 +41,8 @@ func (c *packet) LocalAddr() net.Addr {
 }
 
 func (c *packet) Drop() {
-	pool.Put(c.buf)
+	_ = pool.Put(c.buf)
+	c.buf = nil
 }
 
 func (c *packet) InAddr() net.Addr {

listener/tunnel/packet.go

@@ -27,7 +27,8 @@ func (c *packet) LocalAddr() net.Addr {
 }
 
 func (c *packet) Drop() {
-	pool.Put(c.payload)
+	_ = pool.Put(c.payload)
+	c.payload = nil
 }
 
 func (c *packet) InAddr() net.Addr {

tunnel/connection.go

@@ -26,7 +26,7 @@ func handleUDPToRemote(packet C.UDPPacket, pc C.PacketConn, metadata *C.Metadata
 	return nil
 }
 
-func handleUDPToLocal(packet C.UDPPacket, pc N.EnhancePacketConn, key string, oAddrPort netip.AddrPort, fAddr netip.Addr) {
+func handleUDPToLocal(writeBack C.WriteBack, pc N.EnhancePacketConn, key string, oAddrPort netip.AddrPort, fAddr netip.Addr) {
 	defer func() {
 		_ = pc.Close()
 		closeAllLocalCoon(key)
@@ -59,7 +59,7 @@ func handleUDPToLocal(packet C.UDPPacket, pc N.EnhancePacketConn, key string, oA
 			log.Warnln("server return a [%T](%s) which isn't a *net.UDPAddr, force replace to (%s), this may be caused by a wrongly implemented server", from, from, oAddrPort)
 		}
 
-		_, err = packet.WriteBack(data, fromUDPAddr)
+		_, err = writeBack.WriteBack(data, fromUDPAddr)
 		if put != nil {
 			put()
 		}

tunnel/tunnel.go

@@ -303,8 +303,11 @@ func handleUDPConn(packet C.PacketAdapter) {
 	key := packet.LocalAddr().String()
 
 	handle := func() bool {
-		pc := natTable.Get(key)
+		pc, proxy := natTable.Get(key)
 		if pc != nil {
+			if proxy != nil {
+				proxy.UpdateWriteBack(packet)
+			}
 			_ = handleUDPToRemote(packet, pc, metadata)
 			return true
 		}
@@ -384,9 +387,10 @@ func handleUDPConn(packet C.PacketAdapter) {
 		}
 
 		oAddrPort := metadata.AddrPort()
-		natTable.Set(key, pc)
+		writeBackProxy := nat.NewWriteBackProxy(packet)
+		natTable.Set(key, pc, writeBackProxy)
 
-		go handleUDPToLocal(packet, pc, key, oAddrPort, fAddr)
+		go handleUDPToLocal(writeBackProxy, pc, key, oAddrPort, fAddr)
 
 		handle()
 	}()