receive handshake address from tls conn

proxy/dokodemo/dokodemo.go

@@ -54,6 +54,10 @@ func (d *DokodemoDoor) policy() core.Policy {
 	return p
 }
 
+type hasHandshakeAddress interface {
+	HandshakeAddress() net.Address
+}
+
 func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn internet.Connection, dispatcher core.Dispatcher) error {
 	newError("processing connection from: ", conn.RemoteAddr()).AtDebug().WriteToLog(session.ExportIDToError(ctx))
 	dest := net.Destination{
@@ -65,6 +69,12 @@ func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn in
 		if origDest, ok := proxy.OriginalTargetFromContext(ctx); ok {
 			dest = origDest
 		}
+		if handshake, ok := conn.(hasHandshakeAddress); ok {
+			addr := handshake.HandshakeAddress()
+			if addr != nil {
+				dest.Address = addr
+			}
+		}
 	}
 	if !dest.IsValid() || dest.Address == nil {
 		return newError("unable to get destination")

transport/internet/tls/tls.go

@@ -2,9 +2,9 @@ package tls
 
 import (
 	"crypto/tls"
-	"net"
 
 	"v2ray.com/core/common/buf"
+	"v2ray.com/core/common/net"
 )
 
 //go:generate go run $GOPATH/src/v2ray.com/core/common/errors/errorgen/main.go -pkg tls -path Transport,Internet,TLS
@@ -14,7 +14,7 @@ var (
 )
 
 type conn struct {
-	net.Conn
+	*tls.Conn
 
 	mergingWriter *buf.BufferedWriter
 }
@@ -29,6 +29,17 @@ func (c *conn) WriteMultiBuffer(mb buf.MultiBuffer) error {
 	return c.mergingWriter.Flush()
 }
 
+func (c *conn) HandshakeAddress() net.Address {
+	if err := c.Handshake(); err != nil {
+		return nil
+	}
+	state := c.Conn.ConnectionState()
+	if len(state.ServerName) == 0 {
+		return nil
+	}
+	return net.ParseAddress(state.ServerName)
+}
+
 // Client initiates a TLS client handshake on the given connection.
 func Client(c net.Conn, config *tls.Config) net.Conn {
 	tlsConn := tls.Client(c, config)