dcnow.py

#!/usr/bin/env python

import threading
import os
import json
import time
import logging
import urllib
import urllib2
import sh

from hashlib import sha256

from uuid import getnode as get_mac

logger = logging.getLogger('dcnow')

API_ROOT = "https://dcnow-2016.appspot.com"
UPDATE_END_POINT = "/api/update/{mac_address}/"

UPDATE_INTERVAL = 15

CONFIGURATION_FILE = os.path.expanduser("~/.dreampi.json")


def scan_mac_address():
    mac = get_mac()
    return sha256(':'.join(("%012X" % mac)[i:i+2] for i in range(0, 12, 2))).hexdigest()


class DreamcastNowThread(threading.Thread):
    def __init__(self, service):
        self._service = service
        self._running = True
        super(DreamcastNowThread, self).__init__()

    def run(self):
        def post_update():
            if not self._service._enabled:
                return

            lines = [ x for x in sh.tail("/var/log/syslog", "-n", "10", _iter=True) ]
            dns_query = None
            for line in lines[::-1]:
                if "CONNECT" in line and "dreampi" in line:
                    # Don't seek back past connection
                    break

                if "query[A]" in line:
                    # We did a DNS lookup, what was it?
                    remainder = line[line.find("query[A]") + len("query[A]"):].strip()
                    domain = remainder.split(" ", 1)[0].strip()
                    dns_query = sha256(domain).hexdigest()
                    break

            user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT), Dreamcast Now'
            header = { 'User-Agent' : user_agent }
            mac_address = self._service._mac_address
            data = {}
            if dns_query:
                data["dns_query"] = dns_query

            data = urllib.urlencode(data)
            req = urllib2.Request(API_ROOT + UPDATE_END_POINT.format(mac_address=mac_address), data, header)
            urllib2.urlopen(req) # Send POST update

        while self._running:
            try:
                post_update()
            except:
                logger.exception("Couldn't update Dreamcast Now!")
            time.sleep(UPDATE_INTERVAL)

    def stop(self):
        self._running = False
        self.join()


class DreamcastNowService(object):
    def __init__(self):
        self._thread = None
        self._mac_address = None
        self._enabled = True
        self.reload_settings()

        logger.setLevel(logging.INFO)
        handler = logging.handlers.SysLogHandler(address='/dev/log')
        logger.addHandler(handler)

    def update_mac_address(self, dreamcast_ip):
        self._mac_address = scan_mac_address()
        logger.info("MAC address: {}".format(self._mac_address))

    def reload_settings(self):
        settings_file = CONFIGURATION_FILE

        if os.path.exists(settings_file):
            with open(settings_file, "r") as settings:
                content = json.loads(settings.read())
                self._enabled = content["enabled"]

    def go_online(self, dreamcast_ip):
        if not self._enabled:
            return

        self.update_mac_address(dreamcast_ip)
        self._thread = DreamcastNowThread(self)
        self._thread.start()

    def go_offline(self):
        self._thread.stop()
        self._thread = None