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# $Id: ntp.py 48 2008-05-27 17:31:15Z yardley $
"""Network Time Protocol."""
import dpkt
# NTP v4
# Leap Indicator (LI) Codes
NO_WARNING = 0
LAST_MINUTE_61_SECONDS = 1
LAST_MINUTE_59_SECONDS = 2
ALARM_CONDITION = 3
# Mode Codes
RESERVED = 0
SYMMETRIC_ACTIVE = 1
SYMMETRIC_PASSIVE = 2
CLIENT = 3
SERVER = 4
BROADCAST = 5
CONTROL_MESSAGE = 6
PRIVATE = 7
class NTP(dpkt.Packet):
__hdr__ = (
('flags', 'B', 0),
('stratum', 'B', 0),
('interval', 'B', 0),
('precision', 'B', 0),
('delay', 'I', 0),
('dispersion', 'I', 0),
('id', '4s', 0),
('update_time', '8s', 0),
('originate_time', '8s', 0),
('receive_time', '8s', 0),
('transmit_time', '8s', 0)
)
def _get_v(self):
return (self.flags >> 3) & 0x7
def _set_v(self, v):
self.flags = (self.flags & ~0x38) | ((v & 0x7) << 3)
v = property(_get_v, _set_v)
def _get_li(self):
return (self.flags >> 6) & 0x3
def _set_li(self, li):
self.flags = (self.flags & ~0xc0) | ((li & 0x3) << 6)
li = property(_get_li, _set_li)
def _get_mode(self):
return (self.flags & 0x7)
def _set_mode(self, mode):
self.flags = (self.flags & ~0x7) | (mode & 0x7)
mode = property(_get_mode, _set_mode)
if __name__ == '__main__':
import unittest
class NTPTestCase(unittest.TestCase):
def testPack(self):
n = NTP(self.s)
self.failUnless(self.s == str(n))
def testUnpack(self):
n = NTP(self.s)
self.failUnless(n.li == NO_WARNING)
self.failUnless(n.v == 4)
self.failUnless(n.mode == SERVER)
self.failUnless(n.stratum == 2)
self.failUnless(n.id == '\xc1\x02\x04\x02')
# test get/set functions
n.li = ALARM_CONDITION
n.v = 3
n.mode = CLIENT
self.failUnless(n.li == ALARM_CONDITION)
self.failUnless(n.v == 3)
self.failUnless(n.mode == CLIENT)
s = '\x24\x02\x04\xef\x00\x00\x00\x84\x00\x00\x33\x27\xc1\x02\x04\x02\xc8\x90\xec\x11\x22\xae\x07\xe5\xc8\x90\xf9\xd9\xc0\x7e\x8c\xcd\xc8\x90\xf9\xd9\xda\xc5\xb0\x78\xc8\x90\xf9\xd9\xda\xc6\x8a\x93'
unittest.main()
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