def run(self): global taskQueue, stopFlag while True: if stopFlag: print("WorkThread Ended") break try: data, addr, recvTimestamp = taskQueue.get(timeout=1) recvPacket = NTPPacket() recvPacket.from_data(data) # Server mode - 4 and SNTP v4 sendPacket = NTPPacket(version=4, mode=4) # According to rfc4330 most fields == 0 # it is already set in NTPPacket constructor # Timestamp Name ID When Generated # ------------------------------------------------------------ # Originate Timestamp T1 time request sent by client # Receive Timestamp T2 time request received by server # Transmit Timestamp T3 time reply sent by server # Destination Timestamp T4 time reply received by client timeStamp_high, timeStamp_low = recvPacket.GetTxTimeStamp() sendPacket.SetOriginTimeStamp(timeStamp_high, timeStamp_low) # Simulate that we have different time on server sendPacket.recv_timestamp = recvTimestamp - self.lie_offset sendPacket.tx_timestamp = ntp_packet.system_to_ntp_time( time.time() - self.lie_offset) # Dummy info to be a correct sntp packet sendPacket.stratum = 2 sendPacket.ref_timestamp = recvTimestamp - 5 sendPacket.poll = 10 # sendPacket.precision = 2 # sendPacket.root_delay = 1 # sendPacket.root_dispersion = 1 # sendPacket.ref_id = 1809582983 # ip 107.220.11.135 # sendPacket = b"\x24\x02\x03\xee\x00\x00\x00\x37\x00\x00\x05\x0f\x6b\xdc\x0b\x87\xd8\xe7\x2f\xa6\x1a\xb4\xc9\x72\xd8\xe7\x30\x27\x66\x15\xdb\x33\xd8\xe7\x30\x26\x02\xe6\xcb\x21\xd8\xe7\x30\x26\x02\xeb\x94\xac" self.m_socket.sendto(sendPacket.to_data(), addr) print("Sended to {}:{}".format(addr[0], addr[1])) except Empty: continue
def fake_server(address): s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.bind( (address, 123) ) drift_start = time.time() speed = 0.9996 while True: packet, source = s.recvfrom(100) print('Received {length} byte packet from {source}'.format(length=len(packet), source=source[0])) packet = NTPPacket.from_bytes(packet) if packet.version not in (3, 4): print('Unsupported NTP version.') continue if packet.mode != 3: print('Not a client request.') continue try: print('Client time:', packet.transmit_timestamp) except: pass time_since_start = time.time() - drift_start return_time = drift_start + time_since_start * speed response = NTPPacket() response.version = packet.version response.mode = 4 response.stratum = 1 response.reference_identifier = b'XFAK' response.origin_timestamp = packet.transmit_timestamp response.reference_timestamp = NTPTimestamp.from_unix_timestamp(return_time) response.receive_timestamp = NTPTimestamp.from_unix_timestamp(return_time) response.transmit_timestamp = NTPTimestamp.from_unix_timestamp(return_time) response = response.to_bytes() s.sendto(response, source)