feat: add udp-over-stream for tuic

only work with meta tuic server or sing-box 1.4.0-beta.6

listener/sing/sing.go

@@ -72,7 +72,27 @@ func UpstreamMetadata(metadata M.Metadata) M.Metadata {
 	}
 }
 
-func (h *ListenerHandler) NewConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
+func ConvertMetadata(metadata *C.Metadata) M.Metadata {
+	return M.Metadata{
+		Protocol:    metadata.Type.String(),
+		Source:      M.SocksaddrFrom(metadata.SrcIP, metadata.SrcPort),
+		Destination: M.ParseSocksaddrHostPort(metadata.String(), metadata.DstPort),
+	}
+}
+
+func (h *ListenerHandler) IsSpecialFqdn(fqdn string) bool {
+	switch fqdn {
+	case mux.Destination.Fqdn:
+	case vmess.MuxDestination.Fqdn:
+	case uot.MagicAddress:
+	case uot.LegacyMagicAddress:
+	default:
+		return false
+	}
+	return true
+}
+
+func (h *ListenerHandler) ParseSpecialFqdn(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
 	switch metadata.Destination.Fqdn {
 	case mux.Destination.Fqdn:
 		return mux.HandleConnection(ctx, h, log.SingLogger, conn, UpstreamMetadata(metadata))
@@ -89,6 +109,13 @@ func (h *ListenerHandler) NewConnection(ctx context.Context, conn net.Conn, meta
 		metadata.Destination = M.Socksaddr{Addr: netip.IPv4Unspecified()}
 		return h.NewPacketConnection(ctx, uot.NewConn(conn, uot.Request{}), metadata)
 	}
+	return errors.New("not special fqdn")
+}
+
+func (h *ListenerHandler) NewConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
+	if h.IsSpecialFqdn(metadata.Destination.Fqdn) {
+		return h.ParseSpecialFqdn(ctx, conn, metadata)
+	}
 	target := socks5.ParseAddr(metadata.Destination.String())
 	wg := &sync.WaitGroup{}
 	defer wg.Wait() // this goroutine must exit after conn.Close()

listener/tuic/server.go

@@ -1,6 +1,7 @@
 package tuic
 
 import (
+	"context"
 	"crypto/tls"
 	"net"
 	"strings"
@@ -11,6 +12,7 @@ import (
 	"github.com/Dreamacro/clash/common/sockopt"
 	C "github.com/Dreamacro/clash/constant"
 	LC "github.com/Dreamacro/clash/listener/config"
+	"github.com/Dreamacro/clash/listener/sing"
 	"github.com/Dreamacro/clash/log"
 	"github.com/Dreamacro/clash/transport/socks5"
 	"github.com/Dreamacro/clash/transport/tuic"
@@ -36,6 +38,12 @@ func New(config LC.TuicServer, tcpIn chan<- C.ConnContext, udpIn chan<- C.Packet
 			inbound.WithSpecialRules(""),
 		}
 	}
+	h := &sing.ListenerHandler{
+		TcpIn:     tcpIn,
+		UdpIn:     udpIn,
+		Type:      C.TUIC,
+		Additions: additions,
+	}
 	cert, err := CN.ParseCert(config.Certificate, config.PrivateKey)
 	if err != nil {
 		return nil, err
@@ -86,7 +94,19 @@ func New(config LC.TuicServer, tcpIn chan<- C.ConnContext, udpIn chan<- C.Packet
 			newAdditions = slices.Clone(additions)
 			newAdditions = append(newAdditions, _additions...)
 		}
-		tcpIn <- inbound.NewSocket(addr, conn, C.TUIC, newAdditions...)
+		connCtx := inbound.NewSocket(addr, conn, C.TUIC, newAdditions...)
+		metadata := sing.ConvertMetadata(connCtx.Metadata())
+		if h.IsSpecialFqdn(metadata.Destination.Fqdn) {
+			go func() { // ParseSpecialFqdn will block, so open a new goroutine
+				_ = h.ParseSpecialFqdn(
+					sing.WithAdditions(context.Background(), newAdditions...),
+					conn,
+					metadata,
+				)
+			}()
+			return nil
+		}
+		tcpIn <- connCtx
 		return nil
 	}
 	handleUdpFn := func(addr socks5.Addr, packet C.UDPPacket, _additions ...inbound.Addition) error {