add pkgs from core

handler/socks/v5/udp.go

@@ -0,0 +1,85 @@
+package v5
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"time"
+
+	"github.com/go-gost/core/common/net/relay"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/gosocks5"
+	"github.com/go-gost/x/internal/util/socks"
+)
+
+func (h *socks5Handler) handleUDP(ctx context.Context, conn net.Conn, log logger.Logger) error {
+	log = log.WithFields(map[string]any{
+		"cmd": "udp",
+	})
+
+	if !h.md.enableUDP {
+		reply := gosocks5.NewReply(gosocks5.NotAllowed, nil)
+		log.Debug(reply)
+		log.Error("socks5: UDP relay is disabled")
+		return reply.Write(conn)
+	}
+
+	cc, err := net.ListenUDP("udp", nil)
+	if err != nil {
+		log.Error(err)
+		reply := gosocks5.NewReply(gosocks5.Failure, nil)
+		reply.Write(conn)
+		log.Debug(reply)
+		return err
+	}
+	defer cc.Close()
+
+	saddr := gosocks5.Addr{}
+	saddr.ParseFrom(cc.LocalAddr().String())
+	saddr.Type = 0
+	saddr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String()) // replace the IP to the out-going interface's
+	reply := gosocks5.NewReply(gosocks5.Succeeded, &saddr)
+	if err := reply.Write(conn); err != nil {
+		log.Error(err)
+		return err
+	}
+	log.Debug(reply)
+
+	log = log.WithFields(map[string]any{
+		"bind": fmt.Sprintf("%s/%s", cc.LocalAddr(), cc.LocalAddr().Network()),
+	})
+	log.Debugf("bind on %s OK", cc.LocalAddr())
+
+	// obtain a udp connection
+	c, err := h.router.Dial(ctx, "udp", "") // UDP association
+	if err != nil {
+		log.Error(err)
+		return err
+	}
+	defer c.Close()
+
+	pc, ok := c.(net.PacketConn)
+	if !ok {
+		err := errors.New("socks5: wrong connection type")
+		log.Error(err)
+		return err
+	}
+
+	r := relay.NewUDPRelay(socks.UDPConn(cc, h.md.udpBufferSize), pc).
+		WithBypass(h.options.Bypass).
+		WithLogger(log)
+	r.SetBufferSize(h.md.udpBufferSize)
+
+	go r.Run()
+
+	t := time.Now()
+	log.Infof("%s <-> %s", conn.RemoteAddr(), cc.LocalAddr())
+	io.Copy(ioutil.Discard, conn)
+	log.WithFields(map[string]any{"duration": time.Since(t)}).
+		Infof("%s >-< %s", conn.RemoteAddr(), cc.LocalAddr())
+
+	return nil
+}