yadyn/server/Event.py

68 lines
2.3 KiB
Python
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2007-11-12 11:17:25 +01:00
import md5
class IllegalEventException(Exception):
def __init__(self, msg):
self.msg = msg
class Event(object):
@classmethod
def setParams(cls, entries, msgTimeCorridor):
cls.entries = entries
cls.msgTimeCorridor = msgTimeCorridor
def __init__(self, address, data, receiveTime):
self.address = address
self.data = data
self.receiveTime = receiveTime
def prepare(self):
self.port = self.address[1]
self.address = self.address[0]
parts = self.data.split(' ')
if len(parts) != 3:
raise IllegalEventException("data format error 1")
(self.dynid, self.msgTime, self.checksum) = self.data.split(' ')
try:
self.msgTime = int(self.msgTime)
except ValueError, e:
raise IllegalEventException("data format error 2")
self.prepared = True
def process(self):
if not self.prepared:
self.prepare()
if not Event.entries.has_key(self.dynid):
raise IllegalEventException("unknown dynid in event %s" % str(self))
entry = Event.entries[self.dynid]
if self.msgTime + Event.msgTimeCorridor < self.receiveTime:
raise IllegalEventException("event too old %s" % str(self))
if self.msgTime - Event.msgTimeCorridor > self.receiveTime:
raise IllegalEventException("event too young %s" % str(self))
if entry.lastEventTime >= self.msgTime:
raise IllegalEventException("timing sequence failure in event, possibly replay %s" % str(self))
di = "%s %s %d" % (self.dynid, entry.sharedSecret, self.msgTime)
d = md5.new(di).hexdigest()
print "%s, received: %s, calculated: %s" % (di, self.checksum, d)
if d != self.checksum:
raise IllegalEventException("wrong checksum for event %s" % str(self))
entry.lastEventTime = self.msgTime
if entry.address == self.address:
print "Same address, nothing to do."
else:
entry.address = self.address
print "Set in DNS: %s -> %s" % (entry.name, entry.address)
def __str__(self):
if not self.prepared:
self.prepare()
return "%s from %s:%d" % (self.data, self.address, self.port)