#!/usr/bin/env python3
 
import sys
from ipaddress import IPv4Network
import http.client as client
from concurrent.futures import ThreadPoolExecutor
import argparse
import ssl
import socket
 
# 先按自己的情況修改以下幾行
APP_ID = 'your_id_here'
APP_PATH = '/fetch.py'
 
context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
context.verify_mode = ssl.CERT_REQUIRED
context.load_verify_locations('/etc/ssl/certs/ca-certificates.crt')
 
class HTTPSConnection(client.HTTPSConnection):
 def __init__(self, *args, hostname=None, **kwargs):
  self._hostname = hostname
  super().__init__(*args, **kwargs)
 
 def connect(self):
  super(client.HTTPSConnection, self).connect()
 
  if self._tunnel_host:
   server_hostname = self._tunnel_host
  else:
   server_hostname = self._hostname or self.host
   sni_hostname = server_hostname if ssl.HAS_SNI else None
 
  self.sock = self._context.wrap_socket(self.sock,
                     server_hostname=sni_hostname)
  if not self._context.check_hostname and self._check_hostname:
   try:
    ssl.match_hostname(self.sock.getpeercert(), server_hostname)
   except Exception:
    self.sock.shutdown(socket.SHUT_RDWR)
    self.sock.close()
    raise
 
def check_ip_p(ip, func):
 if func(ip):
  print(ip, flush=True)
 
def check_for_gae(ip):
 return _check(APP_ID + '.appspot.com', APP_PATH, ip)
 
def check_for_search(ip):
 return _check('www.google.com', '/', ip)
 
def _check(host, path, ip):
 for chance in range(1,-1,-1):
  try:
   conn = HTTPSConnection(
    ip, timeout = 5,
    context = context,
    hostname = host,
   )
   conn.request('GET', path, headers = {
    'Host': host,
   })
   response = conn.getresponse()
   if response.status < 400:
    print('GOOD:', ip, file=sys.stderr)
   else:
    raise Exception('HTTP Error %s %s' % (
     response.status, response.reason))
   return True
  except KeyboardInterrupt:
   raise
  except Exception as e:
   if isinstance(e, ssl.CertificateError):
    print('WARN: %s is not Google\'s!' % ip, file=sys.stderr)
    chance = 0
   if chance == 0:
    print('BAD :', ip, e, file=sys.stderr)
    return False
   else:
    print('RE :', ip, e, file=sys.stderr)
 
def main():
 parser = argparse.ArgumentParser(description='Check Google IPs')
 parser.add_argument('service', choices=['search', 'gae'],
           help='service to check')
 args = parser.parse_args()
 func = globals()['check_for_' + args.service]
 
 count = 0
 with ThreadPoolExecutor(max_workers=50) as executor:
  for l in sys.stdin:
   l = l.strip()
   if '/' in l:
    for ip in IPv4Network(l).hosts():
     executor.submit(check_ip_p, str(ip), func)
     count += 1
   else:
    executor.submit(check_ip_p, l, func)
    count += 1
 print('%d IP checked.' % count)
 
if __name__ == '__main__':
 main()