feat: Expose remote destination (udp proxy maybe domain of node)

adapter/outbound/trojan.go

@@ -13,8 +13,6 @@ import (
 	"github.com/Dreamacro/clash/transport/gun"
 	"github.com/Dreamacro/clash/transport/trojan"
 	"github.com/Dreamacro/clash/transport/vless"
-
-	"golang.org/x/net/http2"
 )
 
 type Trojan struct {
@@ -25,7 +23,7 @@ type Trojan struct {
 	// for gun mux
 	gunTLSConfig *tls.Config
 	gunConfig    *gun.Config
-	transport    *http2.Transport
+	transport    *gun.TransportWrap
 }
 
 type TrojanOption struct {

adapter/outbound/vless.go

@@ -18,8 +18,6 @@ import (
 	"github.com/Dreamacro/clash/transport/gun"
 	"github.com/Dreamacro/clash/transport/vless"
 	"github.com/Dreamacro/clash/transport/vmess"
-
-	"golang.org/x/net/http2"
 )
 
 const (
@@ -35,7 +33,7 @@ type Vless struct {
 	// for gun mux
 	gunTLSConfig *tls.Config
 	gunConfig    *gun.Config
-	transport    *http2.Transport
+	transport    *gun.TransportWrap
 }
 
 type VlessOption struct {

adapter/outbound/vmess.go

@@ -15,8 +15,6 @@ import (
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/transport/gun"
 	"github.com/Dreamacro/clash/transport/vmess"
-
-	"golang.org/x/net/http2"
 )
 
 type Vmess struct {
@@ -27,7 +25,7 @@ type Vmess struct {
 	// for gun mux
 	gunTLSConfig *tls.Config
 	gunConfig    *gun.Config
-	transport    *http2.Transport
+	transport    *gun.TransportWrap
 }
 
 type VmessOption struct {

adapter/outboundgroup/relay.go

@@ -170,6 +170,11 @@ func (r *Relay) proxies(metadata *C.Metadata, touch bool) ([]C.Proxy, []C.Proxy)
 	return targetProxies, chainProxies
 }
 
+func (r *Relay) Addr() string {
+	proxies, _ := r.proxies(nil, true)
+	return proxies[len(proxies)-1].Addr()
+}
+
 func NewRelay(option *GroupCommonOption, providers []provider.ProxyProvider) *Relay {
 	return &Relay{
 		GroupBase: NewGroupBase(GroupBaseOption{

constant/metadata.go

@@ -86,8 +86,12 @@ type Metadata struct {
 	Uid         *int32     `json:"uid"`
 	Process     string     `json:"process"`
 	ProcessPath string     `json:"processPath"`
+	RemoteDst   string     `json:"remoteDestination"`
 }
 
+// avoid stack overflow
+type jsonMetadata Metadata
+
 func (m *Metadata) RemoteAddress() string {
 	return net.JoinHostPort(m.String(), m.DstPort)
 }

transport/gun/gun.go

@@ -39,14 +39,13 @@ type DialFn = func(network, addr string) (net.Conn, error)
 type Conn struct {
 	response  *http.Response
 	request   *http.Request
-	transport *http2.Transport
+	transport *TransportWrap
 	writer    *io.PipeWriter
 	once      sync.Once
 	close     *atomic.Bool
 	err       error
 	remain    int
 	br        *bufio.Reader
-
 	// deadlines
 	deadline *time.Timer
 }
@@ -150,8 +149,8 @@ func (g *Conn) Close() error {
 	return g.writer.Close()
 }
 
-func (g *Conn) LocalAddr() net.Addr                { return &net.TCPAddr{IP: net.IPv4zero, Port: 0} }
+func (g *Conn) LocalAddr() net.Addr                { return g.transport.LocalAddr() }
-func (g *Conn) RemoteAddr() net.Addr               { return &net.TCPAddr{IP: net.IPv4zero, Port: 0} }
+func (g *Conn) RemoteAddr() net.Addr               { return g.transport.RemoteAddr() }
 func (g *Conn) SetReadDeadline(t time.Time) error  { return g.SetDeadline(t) }
 func (g *Conn) SetWriteDeadline(t time.Time) error { return g.SetDeadline(t) }
 
@@ -167,13 +166,15 @@ func (g *Conn) SetDeadline(t time.Time) error {
 	return nil
 }
 
-func NewHTTP2Client(dialFn DialFn, tlsConfig *tls.Config) *http2.Transport {
+func NewHTTP2Client(dialFn DialFn, tlsConfig *tls.Config) *TransportWrap {
+	wrap := TransportWrap{}
 	dialFunc := func(network, addr string, cfg *tls.Config) (net.Conn, error) {
 		pconn, err := dialFn(network, addr)
 		if err != nil {
 			return nil, err
 		}
 
+		wrap.remoteAddr = pconn.RemoteAddr()
 		cn := tls.Client(pconn, cfg)
 
 		// fix tls handshake not timeout
@@ -191,16 +192,18 @@ func NewHTTP2Client(dialFn DialFn, tlsConfig *tls.Config) *http2.Transport {
 		return cn, nil
 	}
 
-	return &http2.Transport{
+	wrap.Transport = &http2.Transport{
 		DialTLS:            dialFunc,
 		TLSClientConfig:    tlsConfig,
 		AllowHTTP:          false,
 		DisableCompression: true,
 		PingTimeout:        0,
 	}
+
+	return &wrap
 }
 
-func StreamGunWithTransport(transport *http2.Transport, cfg *Config) (net.Conn, error) {
+func StreamGunWithTransport(transport *TransportWrap, cfg *Config) (net.Conn, error) {
 	serviceName := "GunService"
 	if cfg.ServiceName != "" {
 		serviceName = cfg.ServiceName

transport/gun/gun_xtls.go

@@ -12,13 +12,15 @@ import (
 	"golang.org/x/net/http2"
 )
 
-func NewHTTP2XTLSClient(dialFn DialFn, tlsConfig *tls.Config) *http2.Transport {
+func NewHTTP2XTLSClient(dialFn DialFn, tlsConfig *tls.Config) *TransportWrap {
+	wrap := TransportWrap{}
 	dialFunc := func(network, addr string, cfg *tls.Config) (net.Conn, error) {
 		pconn, err := dialFn(network, addr)
 		if err != nil {
 			return nil, err
 		}
 
+		wrap.remoteAddr = pconn.RemoteAddr()
 		xtlsConfig := &xtls.Config{
 			InsecureSkipVerify: cfg.InsecureSkipVerify,
 			ServerName:         cfg.ServerName,
@@ -37,13 +39,15 @@ func NewHTTP2XTLSClient(dialFn DialFn, tlsConfig *tls.Config) *http2.Transport {
 		return cn, nil
 	}
 
-	return &http2.Transport{
+	wrap.Transport = &http2.Transport{
 		DialTLS:            dialFunc,
 		TLSClientConfig:    tlsConfig,
 		AllowHTTP:          false,
 		DisableCompression: true,
 		PingTimeout:        0,
 	}
+
+	return &wrap
 }
 
 func StreamGunWithXTLSConn(conn net.Conn, tlsConfig *tls.Config, cfg *Config) (net.Conn, error) {

transport/gun/transport.go

@@ -0,0 +1,20 @@
+package gun
+
+import (
+	"golang.org/x/net/http2"
+	"net"
+)
+
+type TransportWrap struct {
+	*http2.Transport
+	remoteAddr net.Addr
+	localAddr  net.Addr
+}
+
+func (tw *TransportWrap) RemoteAddr() net.Addr {
+	return tw.remoteAddr
+}
+
+func (tw *TransportWrap) LocalAddr() net.Addr {
+	return tw.localAddr
+}

tunnel/tunnel.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -269,6 +270,18 @@ func handleUDPConn(packet *inbound.PacketAdapter) {
 			return
 		}
 		pCtx.InjectPacketConn(rawPc)
+
+		actualProxy := proxy.Unwrap(nil)
+		if actualProxy != nil {
+			if dst, _, err := net.SplitHostPort(actualProxy.Addr()); err == nil {
+				metadata.RemoteDst = dst
+			} else {
+				if addrError, ok := err.(*net.AddrError); ok && strings.Contains(addrError.Err, "missing port") {
+					metadata.RemoteDst = actualProxy.Addr()
+				}
+			}
+		}
+
 		pc := statistic.NewUDPTracker(rawPc, statistic.DefaultManager, metadata, rule)
 
 		switch true {
@@ -332,6 +345,11 @@ func handleTCPConn(connCtx C.ConnContext) {
 		}
 		return
 	}
+
+	if tcpAddr, ok := remoteConn.RemoteAddr().(*net.TCPAddr); ok {
+		metadata.RemoteDst = tcpAddr.IP.String()
+	}
+
 	remoteConn = statistic.NewTCPTracker(remoteConn, statistic.DefaultManager, metadata, rule)
 	defer func(remoteConn C.Conn) {
 		_ = remoteConn.Close()