web2tel

'''
web2tel converts http into telnet.

telnet_server-----(telnet)-----pywebsocket/web2tel-----(http)-----http_client


setup:
 1. Install pywebsocket. 'example' directory is made.
 2. Put 'web2tel_wsh.py' into 'example' directory.

usage:
 1. Running pywebsocket.
    python mod_pywebsocket\standalone.py -p 12345 --allow-draft75 -d example
 2. Accessing from http_client(follow websocket) to pywebsocket.
    http://localhost/console.html
 3. Connect to web2tel.
    ws://localhost/web2tel
 4. Sending connect string.
    <connect>telnet_server
    e.g.)
         <connect>192.168.0.1
    Telnet session is begun.
 5. After telnet session started, send arbitrary string.
'''

import telnetlib
import threading
import time
import re
import locale


class TelnetClass():
    def __init__(self, node, request):
        self.node = node
        self.request = request

    def connect(self):
        self.tn = telnetlib.Telnet(self.node, 23)
        self.reader = ReaderClass(self.tn, self.request)

    def send(self, send_string):
        self.tn.write(str(send_string))
        self.tn.write('\r\n')


class ReaderClass(threading.Thread):
    def __init__(self, tn, request):
        threading.Thread.__init__(self)
        self.setDaemon(True)
        self.tn = tn
        self.request = request
        self.start()

    def run(self):
        while True:
            reply_data = self.tn.read_very_eager()

            if reply_data != '':
                self.request.ws_stream.send_message(reply_data.decode('utf-8'))
            else:
                time.sleep(1)


def web_socket_do_extra_handshake(request):
    pass


def web_socket_transfer_data(request):
    while True:
        line = request.ws_stream.receive_message()

        if re.match('\<connect\>', line):
            node = re.sub('\<connect\>', '', line)
            tel = TelnetClass(node, request)
            tel.connect()
        else:
            tel.send(line)