title: how to write a tcp proxy?
body: <p>I am  curious  about  the <strong>tcp proxy implementation</strong>.</p>
  
  <p>Can you give me some <strong>tips</strong> about how to understand and develop  a  naive version?</p>
  
  <p>And is there any good <strong>materials(or open projects)</strong> or <strong>tutorial</strong> on it?  =)</p>