133 lines
2.1 KiB
Go
133 lines
2.1 KiB
Go
package relay
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"io"
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"math"
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"net"
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"sync"
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"github.com/go-gost/relay"
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)
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type tcpConn struct {
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net.Conn
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wbuf bytes.Buffer
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once sync.Once
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}
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func (c *tcpConn) Read(b []byte) (n int, err error) {
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c.once.Do(func() {
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err = readResponse(c.Conn)
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})
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if err != nil {
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return
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}
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return c.Conn.Read(b)
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}
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func (c *tcpConn) Write(b []byte) (n int, err error) {
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n = len(b) // force byte length consistent
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if c.wbuf.Len() > 0 {
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c.wbuf.Write(b) // append the data to the cached header
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_, err = c.Conn.Write(c.wbuf.Bytes())
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c.wbuf.Reset()
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return
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}
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_, err = c.Conn.Write(b)
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return
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}
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type udpConn struct {
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net.Conn
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wbuf bytes.Buffer
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once sync.Once
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}
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func (c *udpConn) Read(b []byte) (n int, err error) {
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c.once.Do(func() {
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err = readResponse(c.Conn)
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})
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if err != nil {
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return
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}
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var bb [2]byte
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_, err = io.ReadFull(c.Conn, bb[:])
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if err != nil {
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return
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}
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dlen := int(binary.BigEndian.Uint16(bb[:]))
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if len(b) >= dlen {
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return io.ReadFull(c.Conn, b[:dlen])
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}
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buf := make([]byte, dlen)
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_, err = io.ReadFull(c.Conn, buf)
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n = copy(b, buf)
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return
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}
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func (c *udpConn) Write(b []byte) (n int, err error) {
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if len(b) > math.MaxUint16 {
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err = errors.New("write: data maximum exceeded")
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return
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}
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n = len(b)
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if c.wbuf.Len() > 0 {
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var bb [2]byte
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binary.BigEndian.PutUint16(bb[:], uint16(len(b)))
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c.wbuf.Write(bb[:])
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c.wbuf.Write(b) // append the data to the cached header
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_, err = c.wbuf.WriteTo(c.Conn)
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return
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}
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var bb [2]byte
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binary.BigEndian.PutUint16(bb[:], uint16(len(b)))
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_, err = c.Conn.Write(bb[:])
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if err != nil {
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return
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}
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return c.Conn.Write(b)
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}
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func readResponse(r io.Reader) (err error) {
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resp := relay.Response{}
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_, err = resp.ReadFrom(r)
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if err != nil {
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return
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}
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if resp.Version != relay.Version1 {
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err = relay.ErrBadVersion
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return
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}
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if resp.Status != relay.StatusOK {
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err = fmt.Errorf("status %d", resp.Status)
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return
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}
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return nil
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}
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type bindConn struct {
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net.Conn
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localAddr net.Addr
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remoteAddr net.Addr
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}
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func (c *bindConn) LocalAddr() net.Addr {
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return c.localAddr
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}
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func (c *bindConn) RemoteAddr() net.Addr {
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return c.remoteAddr
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}
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