add buffer size option for udp connection

internal/util/relay/conn.go

@@ -1,10 +1,8 @@
 package relay
 
 import (
-	"bytes"
 	"net"
 
-	"github.com/go-gost/core/common/bufpool"
 	"github.com/go-gost/gosocks5"
 	"github.com/go-gost/relay"
 )
@@ -108,89 +106,3 @@ func (c *udpTunConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
 func (c *udpTunConn) Write(b []byte) (n int, err error) {
 	return c.WriteTo(b, c.taddr)
 }
-
-var (
-	DefaultBufferSize = 4096
-)
-
-type udpConn struct {
-	net.PacketConn
-	raddr      net.Addr
-	taddr      net.Addr
-	bufferSize int
-}
-
-func UDPConn(c net.PacketConn, bufferSize int) net.PacketConn {
-	return &udpConn{
-		PacketConn: c,
-		bufferSize: bufferSize,
-	}
-}
-
-// ReadFrom reads an UDP datagram.
-// NOTE: for server side,
-// the returned addr is the target address the client want to relay to.
-func (c *udpConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
-	rbuf := bufpool.Get(c.bufferSize)
-	defer bufpool.Put(rbuf)
-
-	n, c.raddr, err = c.PacketConn.ReadFrom(rbuf)
-	if err != nil {
-		return
-	}
-
-	socksAddr := gosocks5.Addr{}
-	header := gosocks5.UDPHeader{
-		Addr: &socksAddr,
-	}
-	hlen, err := header.ReadFrom(bytes.NewReader(rbuf[:n]))
-	if err != nil {
-		return
-	}
-	n = copy(b, rbuf[hlen:n])
-
-	addr, err = net.ResolveUDPAddr("udp", socksAddr.String())
-	return
-}
-
-func (c *udpConn) Read(b []byte) (n int, err error) {
-	n, _, err = c.ReadFrom(b)
-	return
-}
-
-func (c *udpConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
-	wbuf := bufpool.Get(c.bufferSize)
-	defer bufpool.Put(wbuf)
-
-	socksAddr := gosocks5.Addr{}
-	if err = socksAddr.ParseFrom(addr.String()); err != nil {
-		return
-	}
-
-	header := gosocks5.UDPHeader{
-		Addr: &socksAddr,
-	}
-	dgram := gosocks5.UDPDatagram{
-		Header: &header,
-		Data:   b,
-	}
-
-	buf := bytes.NewBuffer(wbuf[:0])
-	_, err = dgram.WriteTo(buf)
-	if err != nil {
-		return
-	}
-
-	_, err = c.PacketConn.WriteTo(buf.Bytes(), c.raddr)
-	n = len(b)
-
-	return
-}
-
-func (c *udpConn) Write(b []byte) (n int, err error) {
-	return c.WriteTo(b, c.taddr)
-}
-
-func (c *udpConn) RemoteAddr() net.Addr {
-	return c.raddr
-}