feat: add udp-over-stream for tuic

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

adapter/outbound/tuic.go

@@ -6,6 +6,7 @@ import (
 	"crypto/tls"
 	"encoding/hex"
 	"encoding/pem"
+	"errors"
 	"fmt"
 	"math"
 	"net"
@@ -15,12 +16,15 @@ import (
 
 	"github.com/Dreamacro/clash/component/dialer"
 	"github.com/Dreamacro/clash/component/proxydialer"
+	"github.com/Dreamacro/clash/component/resolver"
 	tlsC "github.com/Dreamacro/clash/component/tls"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/transport/tuic"
 
 	"github.com/gofrs/uuid/v5"
 	"github.com/metacubex/quic-go"
+	M "github.com/sagernet/sing/common/metadata"
+	"github.com/sagernet/sing/common/uot"
 )
 
 type Tuic struct {
@@ -59,6 +63,9 @@ type TuicOption struct {
 	DisableMTUDiscovery  bool   `proxy:"disable-mtu-discovery,omitempty"`
 	MaxDatagramFrameSize int    `proxy:"max-datagram-frame-size,omitempty"`
 	SNI                  string `proxy:"sni,omitempty"`
+
+	UDPOverStream        bool `proxy:"udp-over-stream,omitempty"`
+	UDPOverStreamVersion int  `proxy:"udp-over-stream-version,omitempty"`
 }
 
 // DialContext implements C.ProxyAdapter
@@ -82,6 +89,32 @@ func (t *Tuic) ListenPacketContext(ctx context.Context, metadata *C.Metadata, op
 
 // ListenPacketWithDialer implements C.ProxyAdapter
 func (t *Tuic) ListenPacketWithDialer(ctx context.Context, dialer C.Dialer, metadata *C.Metadata) (_ C.PacketConn, err error) {
+	if t.option.UDPOverStream {
+		uotDestination := uot.RequestDestination(uint8(t.option.UDPOverStreamVersion))
+		uotMetadata := *metadata
+		uotMetadata.Host = uotDestination.Fqdn
+		uotMetadata.DstPort = uotDestination.Port
+		c, err := t.DialContextWithDialer(ctx, dialer, &uotMetadata)
+		if err != nil {
+			return nil, err
+		}
+
+		// tuic uos use stream-oriented udp with a special address, so we need a net.UDPAddr
+		if !metadata.Resolved() {
+			ip, err := resolver.ResolveIP(ctx, metadata.Host)
+			if err != nil {
+				return nil, errors.New("can't resolve ip")
+			}
+			metadata.DstIP = ip
+		}
+
+		destination := M.SocksaddrFromNet(metadata.UDPAddr())
+		if t.option.UDPOverStreamVersion == uot.LegacyVersion {
+			return newPacketConn(uot.NewConn(c, uot.Request{Destination: destination}), t), nil
+		} else {
+			return newPacketConn(uot.NewLazyConn(c, uot.Request{Destination: destination}), t), nil
+		}
+	}
 	pc, err := t.client.ListenPacketWithDialer(ctx, metadata, dialer, t.dialWithDialer)
 	if err != nil {
 		return nil, err
@@ -239,6 +272,14 @@ func NewTuic(option TuicOption) (*Tuic, error) {
 		tlsConfig.InsecureSkipVerify = true // tls: either ServerName or InsecureSkipVerify must be specified in the tls.Config
 	}
 
+	switch option.UDPOverStreamVersion {
+	case uot.Version, uot.LegacyVersion:
+	case 0:
+		option.UDPOverStreamVersion = uot.LegacyVersion
+	default:
+		return nil, fmt.Errorf("tuic %s unknown udp over stream protocol version: %d", addr, option.UDPOverStreamVersion)
+	}
+
 	t := &Tuic{
 		Base: &Base{
 			name:   option.Name,

docs/config.yaml

@@ -681,6 +681,11 @@ proxies: # socks5
     # skip-cert-verify: true
     # max-open-streams: 20 # default 100, too many open streams may hurt performance
     # sni: example.com
+    #
+    # meta和sing-box私有扩展，将ss-uot用于udp中继，开启此选项后udp-relay-mode将失效
+    # 警告，与原版tuic不兼容！！！
+    # udp-over-stream: false
+    # udp-over-stream-version: 1
 
   # ShadowsocksR
   # The supported ciphers (encryption methods): all stream ciphers in ss

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 {