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)