fix command writing code

Fix the code writing commands to the fail2ban socket to correctly encode
the command terminator string. The terminator string should be encoded as
a simple byte array, not using the pickle format. Using the pickle format
allowed the first command to succeed, but would "break" the socket in the
sense that all following commands would fail with an underflow exception.

src/socket/protocol.go

@@ -3,9 +3,7 @@ package socket
 import (
 	"bytes"
 	"fmt"
-	"github.com/kisielk/og-rek"
 	"github.com/nlpodyssey/gopickle/pickle"
-	"net"
 )
 
 const (
@@ -15,28 +13,28 @@ const (
 )
 
 func (s *Fail2BanSocket) sendCommand(command []string) (interface{}, error) {
-	err := write(s.encoder, command)
+	err := s.write(command)
 	if err != nil {
 		return nil, err
 	}
-	return read(&s.socket)
+	return s.read()
 }
 
-func write(encoder *ogórek.Encoder, command []string) error {
+func (s *Fail2BanSocket) write(command []string) error {
-	err := encoder.Encode(command)
+	err := s.encoder.Encode(command)
 	if err != nil {
 		return err
 	}
-	err = encoder.Encode(commandTerminator)
+	_, err = s.socket.Write([]byte(commandTerminator))
 	if err != nil {
 		return err
 	}
 	return nil
 }
 
-func read(s *net.Conn) (interface{}, error) {
+func (s *Fail2BanSocket) read() (interface{}, error) {
 	buf := make([]byte, socketReadBufferSize)
-	_, err := (*s).Read(buf)
+	_, err := s.socket.Read(buf)
 	if err != nil {
 		return nil, err
 	}