From aeb0acab33f4add80e44807f2a82eb87caa08a85 Mon Sep 17 00:00:00 2001
From: nadoo <287492+nadoo@users.noreply.github.com>
Date: Fri, 8 Sep 2017 12:09:57 +0800
Subject: [PATCH] ss: add udp over tcp support

---
 README.md |  2 +-
 server.go |  3 +++
 ss.go     | 42 +++++++++++++++++++++++++++++++++++++++---
 3 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 13e671a..0ee874f 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ General:
 - Rule proxy based on destinations: [Config Examples](config/examples)
 
 TODO:
-- [ ] UDP over TCP
+- [x] UDP over TCP (ss)
 - [ ] UDP Tunnel
 - [ ] Linux tproxy support & UDP Relay
 - [ ] TUN/TAP device support
diff --git a/server.go b/server.go
index ea0edc7..1054c45 100644
--- a/server.go
+++ b/server.go
@@ -57,6 +57,9 @@ func ServerFromURL(s string, sDialer Dialer) (Server, error) {
 	case "dnstun":
 		d := strings.Split(addr, "=")
 		return NewDNSTun(d[0], d[1], sDialer)
+	case "uottun":
+		d := strings.Split(addr, "=")
+		return NewUoTTun(d[0], d[1], sDialer)
 	}
 
 	return nil, errors.New("unknown schema '" + u.Scheme + "'")
diff --git a/ss.go b/ss.go
index aa9332e..5d4600a 100644
--- a/ss.go
+++ b/ss.go
@@ -12,7 +12,7 @@ import (
 	"github.com/shadowsocks/go-shadowsocks2/socks"
 )
 
-const udpBufSize = 64 * 1024
+const udpBufSize = 65536
 
 // SS .
 type SS struct {
@@ -40,7 +40,7 @@ func NewSS(addr, method, pass string, cDialer Dialer, sDialer Dialer) (*SS, erro
 
 // ListenAndServe serves ss requests.
 func (s *SS) ListenAndServe() {
-	go s.ListenAndServeUDP()
+	// go s.ListenAndServeUDP()
 	s.ListenAndServeTCP()
 }
 
@@ -80,6 +80,37 @@ func (s *SS) ServeTCP(c net.Conn) {
 		return
 	}
 
+	// udp over tcp
+	if UoT(tgt[0]) {
+		rc, err := net.ListenPacket("udp", "")
+		if err != nil {
+			logf("UDP remote listen error: %v", err)
+		}
+		defer rc.Close()
+
+		req := make([]byte, udpBufSize)
+		n, err := c.Read(req)
+		if err != nil {
+			logf("error in ioutil.ReadAll: %s\n", err)
+			return
+		}
+
+		tgtAddr, _ := net.ResolveUDPAddr("udp", tgt.String())
+		rc.WriteTo(req[:n], tgtAddr)
+
+		buf := make([]byte, udpBufSize)
+		n, _, err = rc.ReadFrom(buf)
+		if err != nil {
+			logf("proxy-uottun read error: %v", err)
+		}
+
+		c.Write(buf[:n])
+
+		logf("proxy-ss %s <-tcp-> %s <-> %s <-udp-> %s ", c.RemoteAddr(), c.LocalAddr(), rc.LocalAddr(), tgt)
+
+		return
+	}
+
 	rc, err := s.sDialer.Dial("tcp", tgt.String())
 	if err != nil {
 		logf("proxy-ss failed to connect to target: %v", err)
@@ -171,7 +202,12 @@ func (s *SS) Dial(network, addr string) (net.Conn, error) {
 		return nil, errors.New("Unable to parse address: " + addr)
 	}
 
-	c, err := s.cDialer.Dial(network, s.addr)
+	// udp over tcp tag
+	if network == "udp" {
+		target[0] = target[0] | 0x8
+	}
+
+	c, err := s.cDialer.Dial("tcp", s.addr)
 	if err != nil {
 		logf("dial to %s error: %s", s.addr, err)
 		return nil, err