A script to block ads via dnsmasq

update-adblock-dnsmasq.py

#!/usr/bin/env python
from urllib2 import urlopen
from collections import OrderedDict
import re
import os
import sys

def is_valid_hostname(hostname):
    if len(hostname) > 255:
        return False
    if "." not in hostname:
        return False
    if hostname[-1] == ".":
        hostname = hostname[:-1] # strip exactly one dot from the right, if present
    allowed = re.compile("(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
    return all(allowed.match(x) for x in hostname.split("."))


def hosts_to_dnsmasq(hosts, ignore=[], route="0.0.0.0"):
    """Converts a list of hosts to a dnsmasq formatted string

    :param hosts: List of hosts to convert
    :param route: Where to route requests
    :param ignore: A list of hosts to ignore
    :returns: A string of the dnsmasq file
    """
    dnsmasq = ""

    for line in hosts:
        try:
            if line.startswith("#") or '#' in line:
                pass # don't want these
            else:
                if '  ' in line:
                    host = line.split('  ')[1]
                elif ' ' in line:
                    host = line.split(' ')[1]
                elif '\t' in line:
                    host = line.split('\t')[1]
        except IndexError:
            print line

        try:
            if host in ignore or not is_valid_hostname(host):
                pass # ignore these
            else:
                dnsmasq = dnsmasq + "address=/{}/{}\n".format(host, route)
        except UnboundLocalError:
            print line

    return dnsmasq


def hulu_dnsmasq(hulu_servers, server):
    dnsmasq = ""
    for hulu_server in hulu_servers:
        dnsmasq = dnsmasq + "address=/{}/{}\n".format(hulu_server,server)
    return dnsmasq


def gather_hosts(url_list):
    """Grabs hosts entries from a list of url's

    :param url_list: URL list to block
    :returns: List of hosts
    """
    to_return = []
    for host in url_list:
        fetched = urlopen(host).read()
        to_return = to_return + fetched.splitlines()
    # this removes any dupes from the list
    return list(OrderedDict.fromkeys(to_return))


ad_lists = [
    "http://adblock.gjtech.net/?format=unix-hosts",
    "https://adaway.org/hosts.txt",
    "http://hosts-file.net/ad_servers.txt",
    "http://www.malwaredomainlist.com/hostslist/hosts.txt",
    "http://someonewhocares.org/hosts/hosts",
    "http://pgl.yoyo.org/adservers/serverlist.php?hostformat=hosts&showintro=0&startdate%5Bday%5D=&startdate%5Bmonth%5D=&startdate%5Byear%5D=&mimetype=plaintext",
    "http://winhelp2002.mvps.org/hosts.txt",
]

hulu_list = [
    "ads.hulu.com",
    "ads-v-darwin.hulu.com",
    "a.huluad.com",
    "ads.hulu.com"
    "a.huluad.com",
    "hulu.112.2o7.net",
    "huludev.112.2o7.net",
    "ll.a.hulu.com",
    "t2.hulu.com",
    "t2.huluim.com",
    "t-ak.hulu.com",
    "track.hulu.com",
    "tw.i.hulu.com",
    "urlcheck.hulu.com"
]

ignore_list = [
    "btg.mtvnservices.com", # required, don't remove for hulu
    "tears.io"
]

video_server = "192.168.0.138"
config_file = "/etc/dnsmasq.d/dnsmasq.adlist.conf"

hosts = gather_hosts(ad_lists)

dnsmasq = hosts_to_dnsmasq(hosts, ignore_list)

dnsmasq = dnsmasq + hulu_dnsmasq(hulu_list, video_server)

try:
    f = open(config_file,'w')
    f.write(dnsmasq)
    f.close()
except IOError:
    print("Failed to write to /etc/dnsmasq.d/dnsmasq.adlist.conf, permission denied")
    sys.exit(1)

os.system("/etc/init.d/dnsmasq force-reload")