clash/component/snell/snell.go

92 lines
1.6 KiB
Go

package snell
import (
"bytes"
"encoding/binary"
"errors"
"io"
"net"
"sync"
"github.com/Dreamacro/go-shadowsocks2/shadowaead"
"golang.org/x/crypto/chacha20poly1305"
)
const (
CommandPing byte = 0
CommandConnect byte = 1
CommandTunnel byte = 0
CommandError byte = 2
Version byte = 1
)
var (
bufferPool = sync.Pool{New: func() interface{} { return &bytes.Buffer{} }}
)
type Snell struct {
net.Conn
buffer [1]byte
reply bool
}
func (s *Snell) Read(b []byte) (int, error) {
if s.reply {
return s.Conn.Read(b)
}
s.reply = true
if _, err := io.ReadFull(s.Conn, s.buffer[:]); err != nil {
return 0, err
}
if s.buffer[0] == CommandTunnel {
return s.Conn.Read(b)
} else if s.buffer[0] != CommandError {
return 0, errors.New("Command not support")
}
// CommandError
if _, err := io.ReadFull(s.Conn, s.buffer[:]); err != nil {
return 0, err
}
length := int(s.buffer[0])
msg := make([]byte, length)
if _, err := io.ReadFull(s.Conn, msg); err != nil {
return 0, err
}
return 0, errors.New(string(msg))
}
func WriteHeader(conn net.Conn, host string, port uint) error {
buf := bufferPool.Get().(*bytes.Buffer)
buf.Reset()
defer bufferPool.Put(buf)
buf.WriteByte(Version)
buf.WriteByte(CommandConnect)
// clientID length & id
buf.WriteByte(0)
// host & port
buf.WriteByte(uint8(len(host)))
buf.WriteString(host)
binary.Write(buf, binary.BigEndian, uint16(port))
if _, err := conn.Write(buf.Bytes()); err != nil {
return err
}
return nil
}
func StreamConn(conn net.Conn, psk []byte) net.Conn {
cipher := &snellCipher{psk, chacha20poly1305.New}
return &Snell{Conn: shadowaead.NewConn(conn, cipher)}
}