def _internal_send_packet(server, port, version, packet=None):
if not packet:
packet = NTPPacket(transmit=time.time() + NTPClient.FORMAT_DIFF)
answer = NTPPacket(version_number=version)
with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
s.settimeout(NTPClient.WAITING_TIME)
s.sendto(packet.pack(), (server, port))
data = s.recv(48)
arrive_time = time.time() + NTPClient.FORMAT_DIFF
answer.unpack(data)
return answer, arrive_time
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)
def run_server(delay, port):
with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as sock:
try:
sock.bind(("127.0.0.1", port))
except Exception:
print("Can not create server (sure port is free)")
return
while True:
data, address = sock.recvfrom(1024)
print("Connected: ", address)
try:
packet = NTPPacket().unpack(data)
except UnpackError:
print("Wrong packet format")
sock.sendto(b"Wrong packet format", address)
continue
thread = threading.Thread(target=handle_connection,
args=(packet, sock, address, delay))
thread.start()
