def listen(self) -> bytes:
while True:
packet = self.duplex.listen()
if packet.syn:
if self.state == TCPState.CLOSED:
self.duplex.send(Packet(b'', syn=True))
self.state = TCPState.SYN_SENT
logging.info('set to SYN_SENT')
elif self.state == TCPState.SYN_SENT:
self.state = TCPState.ESTABLISHED
self.duplex.send(Packet(b'', syn=True))
logging.info('set to ESTABLISHED')
self.connection_established.release()
else:
return packet.data
def __init__(self, socket: Socket):
self.socket = socket
self.receiver_expected_seq_num = 1
self.receiver_send_packet = Packet(b'', ack=True, acknum=0)
self.base = 1
self.sender_next_seq_num = 1
self.sender_send_packets: List[Optional[Packet]] = [None] * N
self.send_lock = Lock()
self.timer = Timer(self.timeout)
def spam(sender: Duplex):
for d in [
b'Line numero 1',
b'Line numero 2',
b'Line numero 3',
b'Line numero 4',
b'Line numero 5',
b'Line numero 6',
b'Line numero 7',
]:
logging.info(f'sent data {d}')
sender.send(Packet(d))
sleep(1)
def send(self, orig_packet: Packet) -> bool:
if self.sender_next_seq_num < self.base + N:
self.send_lock.acquire()
orig_packet.seqnum = self.sender_next_seq_num
self.sender_send_packets[self.sender_next_seq_num] = orig_packet
self.socket.send(self.sender_send_packets[self.sender_next_seq_num])
if not self.timer.is_running():
self.timer.start_timer()
self.sender_next_seq_num += 1
self.send_lock.release()
else:
return False
return True
def listen(self) -> Packet:
while True:
packet = self.socket.listen()
if packet.ack:
for p in self.sender_send_packets:
if p:
if p.seqnum > packet.acknum:
break
p.is_acked = True
logging.debug(f'Got ack ({packet}) for {p}')
if packet.acknum > self.base:
self.base = packet.acknum
if any(map(lambda p: p and p.is_acked, self.sender_send_packets)):
self.timer.start_timer()
else:
logging.debug(f'received packet {packet}, {self.receiver_expected_seq_num}')
if packet.seqnum == self.receiver_expected_seq_num:
self.receiver_send_packet = Packet(b'', ack=True, acknum=self.receiver_expected_seq_num)
self.socket.send(self.receiver_send_packet)
self.receiver_expected_seq_num += 1
return packet
else:
self.socket.send(self.receiver_send_packet)
def spam(sender: Duplex):
for d in [b'kek', b'mem']:
logging.info(f'sent data {d}')
sender.send(Packet(d))
sleep(1)
def establish(self):
self.duplex.send(Packet(b'', syn=True))
self.state = TCPState.SYN_SENT
self.connection_established.acquire()
self.connection_established.release()
def send(self, data: bytes) -> bool:
if self.state == TCPState.ESTABLISHED:
return self.duplex.send(Packet(data))
return False