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## This file is part of Scapy
## See http://www.secdev.org/projects/scapy for more informations
## Copyright (C) Philippe Biondi <phil@secdev.org>
## This program is published under a GPLv2 license
"""
NTP (Network Time Protocol).
"""
import time
from scapy.packet import *
from scapy.fields import *
from scapy.layers.inet import UDP
# seconds between 01-01-1900 and 01-01-1970
_NTP_BASETIME = 2208988800
class TimeStampField(FixedPointField):
def __init__(self, name, default):
FixedPointField.__init__(self, name, default, 64, 32)
def i2repr(self, pkt, val):
if val is None:
return "--"
val = self.i2h(pkt,val)
if val < _NTP_BASETIME:
return val
return time.strftime("%a, %d %b %Y %H:%M:%S +0000", time.gmtime(val-_NTP_BASETIME))
def any2i(self, pkt, val):
if type(val) is str:
return int(time.mktime(time.strptime(val))) + _NTP_BASETIME + 3600 # XXX
return FixedPointField.any2i(self,pkt,val)
def i2m(self, pkt, val):
if val is None:
val = FixedPointField.any2i(self, pkt, time.time()+_NTP_BASETIME)
return FixedPointField.i2m(self, pkt, val)
class NTP(Packet):
# RFC 1769
name = "NTP"
fields_desc = [
BitEnumField('leap', 0, 2,
{ 0: 'nowarning',
1: 'longminute',
2: 'shortminute',
3: 'notsync'}),
BitField('version', 3, 3),
BitEnumField('mode', 3, 3,
{ 0: 'reserved',
1: 'sym_active',
2: 'sym_passive',
3: 'client',
4: 'server',
5: 'broadcast',
6: 'control',
7: 'private'}),
BitField('stratum', 2, 8),
BitField('poll', 0xa, 8), ### XXX : it's a signed int
BitField('precision', 0, 8), ### XXX : it's a signed int
FixedPointField('delay', 0, size=32, frac_bits=16),
FixedPointField('dispersion', 0, size=32, frac_bits=16),
IPField('id', "127.0.0.1"),
TimeStampField('ref', 0),
TimeStampField('orig', None), # None means current time
TimeStampField('recv', 0),
TimeStampField('sent', None)
]
def mysummary(self):
return self.sprintf("NTP v%ir,NTP.version%, %NTP.mode%")
bind_layers( UDP, NTP, dport=123, sport=123)
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