def handshake(self):
self.__conn.sendto(
Packet(SYN, 0, address, port, None).to_bytes(),
(self.__router_address, self.__router_port))
data, sender = self.__conn.recvfrom(MAX_LEN)
packet = Packet.from_bytes(data)
if packet.packet_type == SYN_ACK:
response_packet = Packet(ACK, packet.seq_num + 1,
packet.peer_ip_addr, packet.peer_port,
None)
self.__conn.sendto(response_packet.to_bytes(),
(sender[0], sender[1]))
def accept(self):
packet, sender = self.recv_packet()
if packet.packet_type == SYN:
response_packet = Packet(SYN_ACK, packet.seq_num + 1,
packet.peer_ip_addr, packet.peer_port,
None)
self._conn.sendto(response_packet.to_bytes(),
(sender[0], sender[1]))
packet_ack, sender_ack = self.recv_packet()
if packet_ack.packet_type == ACK:
# Connection established
connection = Connection(packet_ack.peer_ip_addr,
packet_ack.peer_port, self)
self._list_of_connections.append(connection)
return connection, sender
def send_packet(self, packet: Packet):
timeout = 5
max_tries = 5
count = 0
while count < max_tries:
try:
self.__conn.sendto(packet.to_bytes(),
(self.__router_address, self.__router_port))
self.__conn.settimeout(timeout)
response, sender = self.__conn.recvfrom(MAX_LEN)
response_packet = Packet.from_bytes(response)
while response_packet.packet_type != ACK:
response, sender = self.__conn.recvfrom(MAX_LEN)
response_packet = Packet.from_bytes(response)
return packet, sender
except socket.timeout:
count += 1
def recv(self, buffer_size):
from common.Packet import Packet
data, sender = self.__receiver.get_connection().recvfrom(buffer_size)
packet = Packet.from_bytes(data)
return packet.payload
def create_packets(self, data: str):
chunks = Sender.chunk_data(data.encode('utf-8'), MAX_LEN - MIN_LEN)
for chunk in chunks:
yield Packet(DATA, self._get_and_increment_sequence_number(),
self.__address, self.__port, chunk)
def handle_data_packet(self, packet, sender):
self._conn.sendto(
Packet(ACK, 0, packet.peer_ip_addr, packet.peer_port,
None).to_bytes(), sender)
def recv_packet(self):
data, sender = self._conn.recvfrom(MAX_LEN)
packet = Packet.from_bytes(data)
return packet, sender