ss: support proxy chain in udp over tcp mode

conn.go

@@ -52,30 +52,3 @@ func relay(left, right net.Conn) (int64, int64, error) {
 	}
 	return n, rs.N, err
 }
-
-// copy from src to dst at target with read timeout
-func timedCopy(dst net.PacketConn, target net.Addr, src net.PacketConn, timeout time.Duration, srcIncluded bool) error {
-	buf := make([]byte, udpBufSize)
-
-	for {
-		src.SetReadDeadline(time.Now().Add(timeout))
-		n, raddr, err := src.ReadFrom(buf)
-		if err != nil {
-			return err
-		}
-
-		if srcIncluded { // server -> client: add original packet source
-			srcAddr := ParseAddr(raddr.String())
-			copy(buf[len(srcAddr):], buf[:n])
-			copy(buf, srcAddr)
-			_, err = dst.WriteTo(buf[:len(srcAddr)+n], target)
-		} else { // client -> user: strip original packet source
-			srcAddr := SplitAddr(buf[:n])
-			_, err = dst.WriteTo(buf[len(srcAddr):n], target)
-		}
-
-		if err != nil {
-			return err
-		}
-	}
-}

rule.go

@@ -63,7 +63,7 @@ func (p *RuleDialer) NextDialer(dstAddr string) Dialer {
 	host, _, err := net.SplitHostPort(dstAddr)
 	if err != nil {
 		// TODO: check here
-		logf("SplitHostPort ERROR: %s", err)
+		// logf("proxy-rule SplitHostPort ERROR: %s", err)
 		return p.gDialer
 	}
 

ss.go

@@ -71,8 +71,12 @@ func (s *SS) Serve(c net.Conn) {
 		return
 	}
 
-	// udp over tcp
-	if UoT(tgt[0]) {
+	dialer := s.sDialer.NextDialer("")
+
+	// udp over tcp?
+	uot := UoT(tgt[0])
+	if uot && dialer.Addr() == "DIRECT" {
+
 		rc, err := net.ListenPacket("udp", "")
 		if err != nil {
 			logf("UDP remote listen error: %v", err)
@@ -102,7 +106,12 @@ func (s *SS) Serve(c net.Conn) {
 		return
 	}
 
-	rc, err := s.sDialer.Dial("tcp", tgt.String())
+	network := "tcp"
+	if uot {
+		network = "udp"
+	}
+
+	rc, err := dialer.Dial(network, tgt.String())
 	if err != nil {
 		logf("proxy-ss failed to connect to target: %v", err)
 		return