Add TUIC protocol

transport/tuic/server_packet.go

@@ -0,0 +1,73 @@
+package tuic
+
+import (
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+)
+
+func (s *serverSession) loopMessages() {
+	select {
+	case <-s.connDone:
+		return
+	case <-s.authDone:
+	}
+	for {
+		message, err := s.quicConn.ReceiveMessage(s.ctx)
+		if err != nil {
+			s.closeWithError(E.Cause(err, "receive message"))
+			return
+		}
+		hErr := s.handleMessage(message)
+		if hErr != nil {
+			s.closeWithError(E.Cause(hErr, "handle message"))
+			return
+		}
+	}
+}
+
+func (s *serverSession) handleMessage(data []byte) error {
+	if len(data) < 2 {
+		return E.New("invalid message")
+	}
+	if data[0] != Version {
+		return E.New("unknown version ", data[0])
+	}
+	switch data[1] {
+	case CommandPacket:
+		message := udpMessagePool.Get().(*udpMessage)
+		err := decodeUDPMessage(message, data[2:])
+		if err != nil {
+			message.release()
+			return E.Cause(err, "decode UDP message")
+		}
+		s.handleUDPMessage(message, false)
+		return nil
+	case CommandHeartbeat:
+		return nil
+	default:
+		return E.New("unknown command ", data[0])
+	}
+}
+
+func (s *serverSession) handleUDPMessage(message *udpMessage, udpStream bool) {
+	s.udpAccess.RLock()
+	udpConn, loaded := s.udpConnMap[message.sessionID]
+	s.udpAccess.RUnlock()
+	if !loaded || common.Done(udpConn.ctx) {
+		udpConn = newUDPPacketConn(s.ctx, s.quicConn, udpStream, true, func() {
+			s.udpAccess.Lock()
+			delete(s.udpConnMap, message.sessionID)
+			s.udpAccess.Unlock()
+		})
+		udpConn.sessionID = message.sessionID
+		s.udpAccess.Lock()
+		s.udpConnMap[message.sessionID] = udpConn
+		s.udpAccess.Unlock()
+		go s.handler.NewPacketConnection(udpConn.ctx, udpConn, M.Metadata{
+			Source:      s.source,
+			Destination: message.destination,
+		})
+	}
+	udpConn.inputPacket(message)
+}