82 lines
1.4 KiB
Go
82 lines
1.4 KiB
Go
package relay
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/binary"
|
|
"errors"
|
|
"io"
|
|
"math"
|
|
"net"
|
|
)
|
|
|
|
type tcpConn struct {
|
|
net.Conn
|
|
wbuf bytes.Buffer
|
|
}
|
|
|
|
func (c *tcpConn) Read(b []byte) (n int, err error) {
|
|
if err != nil {
|
|
return
|
|
}
|
|
return c.Conn.Read(b)
|
|
}
|
|
|
|
func (c *tcpConn) Write(b []byte) (n int, err error) {
|
|
n = len(b) // force byte length consistent
|
|
if c.wbuf.Len() > 0 {
|
|
c.wbuf.Write(b) // append the data to the cached header
|
|
_, err = c.wbuf.WriteTo(c.Conn)
|
|
return
|
|
}
|
|
_, err = c.Conn.Write(b)
|
|
return
|
|
}
|
|
|
|
type udpConn struct {
|
|
net.Conn
|
|
wbuf bytes.Buffer
|
|
}
|
|
|
|
func (c *udpConn) Read(b []byte) (n int, err error) {
|
|
var bb [2]byte
|
|
_, err = io.ReadFull(c.Conn, bb[:])
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
dlen := int(binary.BigEndian.Uint16(bb[:]))
|
|
if len(b) >= dlen {
|
|
return io.ReadFull(c.Conn, b[:dlen])
|
|
}
|
|
buf := make([]byte, dlen)
|
|
_, err = io.ReadFull(c.Conn, buf)
|
|
n = copy(b, buf)
|
|
|
|
return
|
|
}
|
|
|
|
func (c *udpConn) Write(b []byte) (n int, err error) {
|
|
if len(b) > math.MaxUint16 {
|
|
err = errors.New("write: data maximum exceeded")
|
|
return
|
|
}
|
|
|
|
n = len(b)
|
|
if c.wbuf.Len() > 0 {
|
|
var bb [2]byte
|
|
binary.BigEndian.PutUint16(bb[:], uint16(len(b)))
|
|
c.wbuf.Write(bb[:])
|
|
c.wbuf.Write(b) // append the data to the cached header
|
|
_, err = c.wbuf.WriteTo(c.Conn)
|
|
return
|
|
}
|
|
|
|
var bb [2]byte
|
|
binary.BigEndian.PutUint16(bb[:], uint16(len(b)))
|
|
_, err = c.Conn.Write(bb[:])
|
|
if err != nil {
|
|
return
|
|
}
|
|
return c.Conn.Write(b)
|
|
}
|