add udp relay support for http handler

pkg/handler/socks/v5/udp_tun.go

@@ -2,13 +2,13 @@ package v5
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"time"
 
 	"github.com/go-gost/gosocks5"
-	"github.com/go-gost/gost/pkg/common/bufpool"
+	"github.com/go-gost/gost/pkg/chain"
 	"github.com/go-gost/gost/pkg/common/util/socks"
+	"github.com/go-gost/gost/pkg/handler"
 )
 
 func (h *socks5Handler) handleUDPTun(ctx context.Context, conn net.Conn, network, address string) {
@@ -24,111 +24,43 @@ func (h *socks5Handler) handleUDPTun(ctx context.Context, conn net.Conn, network
 		return
 	}
 
-	bindAddr, _ := net.ResolveUDPAddr(network, address)
-	pc, err := net.ListenUDP(network, bindAddr)
-	if err != nil {
-		h.logger.Error(err)
-		return
-	}
-	defer pc.Close()
-
-	saddr, _ := gosocks5.NewAddr(pc.LocalAddr().String())
-	saddr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String())
-	saddr.Type = 0
-	reply := gosocks5.NewReply(gosocks5.Succeeded, saddr)
+	// dummy bind
+	reply := gosocks5.NewReply(gosocks5.Succeeded, nil)
 	if err := reply.Write(conn); err != nil {
 		h.logger.Error(err)
 		return
 	}
 	h.logger.Debug(reply)
 
-	h.logger = h.logger.WithFields(map[string]interface{}{
-		"bind": fmt.Sprintf("%s/%s", pc.LocalAddr(), pc.LocalAddr().Network()),
-	})
+	// obtain a udp connection
+	r := (&chain.Router{}).
+		WithChain(h.chain).
+		WithRetry(h.md.retryCount).
+		WithLogger(h.logger)
+	c, err := r.Dial(ctx, "udp", "") // UDP association
+	if err != nil {
+		h.logger.Error(err)
+		return
+	}
+	defer c.Close()
 
-	h.logger.Debugf("bind on %s OK", pc.LocalAddr())
+	pc, ok := c.(net.PacketConn)
+	if !ok {
+		h.logger.Errorf("wrong connection type")
+		return
+	}
+
+	relay := handler.NewUDPRelay(socks.UDPTunServerConn(conn), pc).
+		WithBypass(h.bypass).
+		WithLogger(h.logger)
+	relay.SetBufferSize(h.md.udpBufferSize)
 
 	t := time.Now()
 	h.logger.Infof("%s <-> %s", conn.RemoteAddr(), pc.LocalAddr())
-	h.tunnelServerUDP(
-		socks.UDPTunServerConn(conn),
-		pc,
-	)
+	relay.Run()
 	h.logger.
 		WithFields(map[string]interface{}{
 			"duration": time.Since(t),
 		}).
 		Infof("%s >-< %s", conn.RemoteAddr(), pc.LocalAddr())
 }
-
-func (h *socks5Handler) tunnelServerUDP(tunnel, c net.PacketConn) (err error) {
-	bufSize := h.md.udpBufferSize
-	errc := make(chan error, 2)
-
-	go func() {
-		for {
-			err := func() error {
-				b := bufpool.Get(bufSize)
-				defer bufpool.Put(b)
-
-				n, raddr, err := tunnel.ReadFrom(b)
-				if err != nil {
-					return err
-				}
-
-				if h.bypass != nil && h.bypass.Contains(raddr.String()) {
-					h.logger.Warn("bypass: ", raddr)
-					return nil
-				}
-
-				if _, err := c.WriteTo(b[:n], raddr); err != nil {
-					return err
-				}
-
-				h.logger.Debugf("%s >>> %s data: %d",
-					c.LocalAddr(), raddr, n)
-
-				return nil
-			}()
-
-			if err != nil {
-				errc <- err
-				return
-			}
-		}
-	}()
-
-	go func() {
-		for {
-			err := func() error {
-				b := bufpool.Get(bufSize)
-				defer bufpool.Put(b)
-
-				n, raddr, err := c.ReadFrom(b)
-				if err != nil {
-					return err
-				}
-
-				if h.bypass != nil && h.bypass.Contains(raddr.String()) {
-					h.logger.Warn("bypass: ", raddr)
-					return nil
-				}
-
-				if _, err := tunnel.WriteTo(b[:n], raddr); err != nil {
-					return err
-				}
-				h.logger.Debugf("%s <<< %s data: %d",
-					c.LocalAddr(), raddr, n)
-
-				return nil
-			}()
-
-			if err != nil {
-				errc <- err
-				return
-			}
-		}
-	}()
-
-	return <-errc
-}