def handle_ack(self, packet):
# TODO: sequence number overflow
if self.piggyback and packet.Data != FIELD_NOT_SET and len(
packet.Data) > 0:
self.handle_data(packet)
self.acknowledgement = packet.Acknowledgement
# print("ack: ", packet.Acknowledgement)
i = 0
while i < len(self.timers):
timer = self.timers[i]
if timer._callbackArgs[0].SequenceNumber < packet.Acknowledgement:
timer.cancel()
self.timers = self.timers[:i] + self.timers[i + 1:]
i -= 1
i += 1
if self.rip_timer != None:
self.rip_timer.cancel()
self.rip_timer.extend(Seconds(2))
self.rip_timer.start()
return
self.send_window_start = max(self.send_window_start,
packet.Acknowledgement)
self.send_window_data()
if self.state == PEEP_Base.TEARDOWN and self.sent_all():
self.send_rip()
self.rip_timer = Timer(Seconds(2), self.abort_connection)
self.rip_timer.start()
def initiate_teardown(self):
# print('teardown start')
self.state = PEEP_Base.TEARDOWN
if self.sent_all():
self.send_rip()
self.rip_timer = Timer(Seconds(2), self.abort_connection)
self.rip_timer.start()
def resend(self, resntPacket):
if "DATA" in resntPacket.Type.upper(): #start timer again
#get timer
for seq, packet, timer, acked in self.sentBoxData:
if seq == resntPacket.SeqNo:
timer.cancel()
index = self.sentBoxData.index((seq, packet, timer, acked))
pacTimer = Timer(Seconds(self.timeoutValue), self.timeout,
packet)
pacTimer.start()
self.sentBoxData[index] = (
seq, packet, pacTimer, False
) #packet seq, packet, timer, acked or not
#start timer
elif "FIN" in resntPacket.Type.upper():
currentTimer = self.sentBoxData[-1][2]
currentTimer.cancel()
currentTimer = Timer(Seconds(self.timeoutValue), self.timeout,
self.sentBoxData[-1][1])
currentTimer.start()
self.sentBoxData[-1] = (self.sentBoxData[-1][0],
self.sentBoxData[-1][1], currentTimer,
False) #last packet since its FIN
elif "ACK" in resntPacket.Type.upper():
if "SYN" in resntPacket.Type.upper():
self.timHand.cancel()
self.timHand = Timer(Seconds(self.timeoutValue), self.timeout,
self.sentHand)
self.timHand.start()
elif "SYN" in resntPacket.Type.upper():
self.stateCon = 0
print("Im here")
self.timHand.cancel()
self.timHand = Timer(Seconds(self.timeoutValue), self.timeout,
self.sentHand)
self.timHand.start()
resendPacket = RIPPacket(Type=resntPacket.Type,
SeqNo=resntPacket.SeqNo,
AckNo=resntPacket.AckNo,
CRC=resntPacket.CRC,
Data=resntPacket.Data)
print("resend packet: Type = {}, SeqNo = {}, AckNo = {},\n CRC = {}".
format(resntPacket.Type, resntPacket.SeqNo, resntPacket.AckNo,
resntPacket.CRC.decode()))
self.transport.write(resendPacket.__serialize__())
def send_packet(self, packet):
# print(self, "send packet: ", packet)
self.transport.write(packet.__serialize__())
if packet.Type != PEEPPacket.SYN and packet.Type != PEEPPacket.DATA and packet.Type != PEEPPacket.RIP:
return
timer = Timer(Seconds(1), self.send_packet, packet)
self.timers.append(timer)
timer.start()
def send(self, pacType, PacData):
sentPacket = RIPPacket()
print("the packet type is: {}".format(pacType))
#calculateSeqAck
if "SYN" in pacType.upper() and "ACK" in pacType.upper():
print("SYN ACK")
#add Ack number
sentPacket.AckNo = self.recHand.SeqNo + 1
#add Seq
sentPacket.SeqNo = self.SequenceNo #random seq
elif "ACK" in pacType.upper():
if self.stateCon == 1:
print("1 ACK")
#add Ack number
sentPacket.AckNo = self.recHand.SeqNo + 1
#add Seq
sentPacket.SeqNo = self.sentHand.SeqNo + 1
elif "SYN" in pacType.upper():
print("SYN")
#add Ack number
sentPacket.AckNo = 0
#add Seq
sentPacket.SeqNo = self.SequenceNo #random seq
elif "DATA" in pacType.upper() or "FIN" in pacType.upper():
if self.sentHand is not None:
print("1st Packet after the Handshake")
#add Ack number
sentPacket.AckNo = 0
#add Seq
sentPacket.SeqNo = self.recHand.AckNo
#empty hands
self.recHand = None
self.sentHand = None
else:
#add Ack number
sentPacket.AckNo = 0
#add Seq
sentPacket.SeqNo = self.sentBoxData[-1][0] + len(
self.sentBoxData[-1][1].Data
) #sequence number and data length of previouse sent packet
if "FIN" in pacType.upper():
self.stateCon = 3 #FIN state
else:
print("IM NOTHING{}".format(sentPacket.AckNo))
#add Type
sentPacket.Type = pacType
#add Data
sentPacket.Data = PacData
#add checksum
sentPacket.CRC = self.hashPacket(sentPacket)
print("checksum is: {}".format(sentPacket.CRC.decode()))
print("send Type ={}, Seq= {}, ACK= {}".format(sentPacket.Type,
sentPacket.SeqNo,
sentPacket.AckNo))
#add packet to the sent list
if "DATA" in pacType.upper() or "FIN" in pacType.upper(
): #not SYN ACK since it will go to the first option
pacTimer = Timer(
Seconds(self.timeoutValue), self.timeout, sentPacket
) #self.timeoutValue = 10 :the RIP layer will wait for 10 seconds until resending the packet
pacTimer.start()
self.sentBoxData.append(
(sentPacket.SeqNo, sentPacket, pacTimer,
False)) #packet seq, packet, timer, acked or not
print("the packe is sent and next Seq number is:{}".format(
sentPacket.SeqNo + len(sentPacket.Data)))
elif "SYN" in pacType.upper(
) or "SYN" in pacType.upper() and "ACK" in pacType.upper():
print("starting a SYN or SYN ACK handshake packets timer")
self.sentHand = sentPacket
self.timHand = Timer(Seconds(self.timeoutValue), self.timeout,
self.sentHand)
self.timHand.start()
print("the timer object is: {}".format(self.timHand))
print("the packe is sent from {} and next Seq number is:{}".format(
self.identity, sentPacket.SeqNo + 1))
for seq, packet, timer, acked in self.sentBoxData:
print("sentBoxData:--- seq= {}, ack= {}, ACKED= {}".format(
seq, seq + len(packet.Data), acked))
#write packet
serPacket = sentPacket.__serialize__()
self.transport.write(sentPacket.__serialize__())