def handle_query(self, transaction_id, query_data):
try:
query_parser = parse.ParseQuery(query_data)
parse_result = query_parser.parse_plain()
query_name_list = parse_result[1]['QNAME']
query_type = parse_result[1]['QTYPE']
query_name = utils.get_domain_name_string(query_name_list)
if self.enable_log:
self.logger.write_log('query_parse_result:' + str(parse_result))
cache_query = None
cached = False
if self.enable_cache and query_name in self.cache and query_type in self.cache[query_name]:
cache_query = self.cache[query_name][query_type]
cache_time = cache_query[1]
cache_ttl = cache_query[2]
current_time = int(time.time())
if current_time - cache_time > cache_ttl:
self.cache[query_name].pop(query_type)
else:
cached = True
if cached:
cache_query_result = cache_query[0]
cache_query_result = bytes.fromhex(transaction_id) + cache_query_result[2:]
sendback_address = self.dns_map[transaction_id][0]
self.server.sendto(cache_query_result, sendback_address)
self.dns_map.pop(transaction_id)
else:
if query_name in self.dns_config['dns_bypass']:
upstream_object = self.bootstrap_dns_object
upstream_object.query(query_data)
elif self.dns_bypass_china:
upstream_object = self.bootstrap_dns_object
upstream_object.query(query_data)
upstream_object = self.select_upstream()
upstream_object.query(query_data)
else:
upstream_object = self.select_upstream()
upstream_object.query(query_data)
except IndexError as exc:
print('[Error]', str(exc))
except KeyboardInterrupt:
exit()
except Exception as exc:
print('[Error]', str(exc))
def start(self):
try:
while True:
recv_data, recv_address = self.server.recvfrom(512)
recv_header = parse.ParseHeader.parse_header(recv_data)
if self.enable_log:
self.logger.write_log('recv_data:' + str(recv_data))
transaction_id = recv_header['transaction_id']
if self.enable_log:
self.logger.write_log('transaction_id:' + str(transaction_id))
if recv_header['flags']['QR'] == '0':
self.dns_map[transaction_id] = [recv_address, 0]
query_thread = threading.Thread(target=self.handle_query, args=(transaction_id, recv_data,))
query_thread.daemon = True
query_thread.start()
elif recv_header['flags']['QR'] == '1' and transaction_id in self.dns_map:
response = self.handle_response(recv_data)
sendback_address = self.dns_map[transaction_id][0]
if self.dns_bypass_china and response[2]:
if len(response[2]) > 1:
ip_address = response[2][-1]['record']
else:
ip_address = response[2][0]['record']
if self.dns_map[transaction_id][1] == 1 or (
utils.is_valid_ipv4_address(ip_address) and utils.is_subnet_address(
'filter_lists/chnroute.txt', ip_address)
):
self.server.sendto(recv_data, sendback_address)
self.dns_map.pop(transaction_id)
elif self.dns_map[transaction_id][1] == 0:
self.dns_map[transaction_id][1] = 1
continue
else:
self.server.sendto(recv_data, sendback_address)
self.dns_map.pop(transaction_id)
if self.enable_cache and response[2]:
response_name = utils.get_domain_name_string(response[1]['QNAME'])
if response_name != '':
response_type = response[1]['QTYPE']
response_ttl = response[2][0]['ttl']
if response_name not in self.cache:
self.cache[response_name] = {}
self.cache[response_name][response_type] = [recv_data, int(time.time()), response_ttl]
except socket.timeout as exc:
print('[Error]', str(exc))
self.start()
except KeyboardInterrupt:
print('Stop Encrypted-DNS Resolver')
exit()
except Exception as exc:
print('[Error]', str(exc))
self.start()
def handle_query(self, transaction_id, query_data):
try:
query_parser = parse.ParseQuery(query_data)
parse_result = query_parser.parse_plain()
query_name_list = parse_result[1]['QNAME']
query_type = parse_result[1]['QTYPE']
query_name = utils.get_domain_name_string(query_name_list)
if self.enable_log:
self.logger.write_log('query_parse_result:' + str(parse_result))
cache_query = None
cached = False
for item in self.hosts.keys():
if query_name == item or (item.startswith("include:") and item.lstrip("include:") in query_name):
response_data = utils.struct_response(query_name, str(transaction_id),
query_type, self.hosts[item][0],
self.hosts[item][1])
sendback_address = self.dns_map[transaction_id][0]
self.server.sendto(response_data, sendback_address)
self.dns_map.pop(transaction_id)
return
if self.enable_cache and query_name in self.cache and query_type in self.cache[query_name]:
cache_query = self.cache[query_name][query_type]
cache_time = cache_query[1]
cache_ttl = cache_query[2]
current_time = int(time.time())
if current_time - cache_time > cache_ttl:
self.cache[query_name].pop(query_type)
else:
cached = True
if cached:
cache_query_result = cache_query[0]
cache_query_result = bytes.fromhex(transaction_id) + cache_query_result[2:]
sendback_address = self.dns_map[transaction_id][0]
self.server.sendto(cache_query_result, sendback_address)
self.dns_map.pop(transaction_id)
else:
if query_name in self.dns_config['dns_bypass']:
upstream_object = self.bootstrap_dns_object
upstream_object.query(query_data)
elif self.dns_bypass_china:
upstream_object = self.bootstrap_dns_object
upstream_object.query(query_data)
upstream_object = self.select_upstream()
upstream_object.query(query_data)
else:
upstream_object = self.select_upstream()
upstream_object.query(query_data)
except IndexError as exc:
print('[Error]', str(exc))
except KeyboardInterrupt:
print('Stop Encrypted-DNS Resolver')
exit()
except Exception as exc:
print('[Error]', str(exc))
raise exc