def listen(self, gateway, address):
size = BUFFER_SIZE
while True:
try:
packet = gateway.recv(size)
if packet:
unpacked = packet_utils.unpack(packet)
client_sequence_num = unpacked.sequence_number
source_ip = unpacked.source_ip
source_port = unpacked.source_port
data = unpacked.data
client_id = source_port
destination_ip = source_ip
destination_port = source_port
if client_id not in self.client_dict:
self.client_dict[client_id] = 0
expected_sequence_number = self.client_dict[client_id]
sequence_number = self.sequence_number
if client_sequence_num == expected_sequence_number:
# 1 in 500 chance to 'drop' the received packet
if randint(1, 500) > 1:
print(data)
self.client_dict[client_id] += 1
if self.client_dict[
client_id] > MAX_SEQUENCE_NUMBER:
self.client_dict[client_id] = 0
next_sequence_number = self.client_dict[client_id]
response_packet = packet_utils.create_packet(
sequence_number, IP, PORT, destination_ip,
destination_port,
bytes(str(next_sequence_number), "utf-8"))
else:
response_packet = packet_utils.create_packet(
sequence_number, IP, PORT, destination_ip,
destination_port,
bytes(str(expected_sequence_number), "utf-8"))
else:
response_packet = packet_utils.create_packet(
sequence_number, IP, PORT, destination_ip,
destination_port,
bytes(str(expected_sequence_number), "utf-8"))
gateway.sendall(response_packet)
gateway.close()
self.sequence_number += 1
if self.sequence_number > MAX_SEQUENCE_NUMBER:
self.sequence_number = 0
else:
gateway.close()
except:
gateway.close()
return
def __init__(self, r_number, sock_addresses, neighbours):
self.r_number = r_number
self.sock_addresses = sock_addresses
self.sockets = []
for i in range(len(sock_addresses)):
self.sockets.append(socket.socket(socket.AF_INET, socket.SOCK_DGRAM))
self.sockets[i].bind((sock_addresses[i][0], sock_addresses[i][1]))
self.neighbours = {}
self.neighbour_nodes = {}
self.destinations = {}
for neighbour in neighbours:
self.neighbours[str(neighbour[0])] = neighbour[1]
self.neighbour_nodes[str(neighbour[0])] = (neighbour[2][0], neighbour[2][1])
# send configuration information to the controller
neighbours_string = str(r_number) + ","
for n in neighbours:
neighbours_string += str(n[0]) + ","
neighbours_string = bytes(neighbours_string[:-1], "utf-8")
packet = packet_utils.create_packet(0, PACKET_TYPE_HELLO, self.sock_addresses[0][0], self.sock_addresses[0][1],
CONTROLLER_IP, CONTROLLER_PORT, neighbours_string)
self.sockets[0].sendto(packet, (CONTROLLER_IP, CONTROLLER_PORT))
n = 0
for sock in self.sockets:
t = threading.Thread(target=self.receive_messages, args=(n, sock))
t.setDaemon(True)
t.start()
n += 1
def send_request(self, source_client, destination_client):
"""
Takes a source and destination client and queries the controller for route information
"""
route = bytes(source_client + "-" + destination_client, "utf-8")
packet = packet_utils.create_packet(0, PACKET_TYPE_LINK_STATE_REQUEST, self.sock_addresses[0][0],
self.sock_addresses[0][1], CONTROLLER_IP, CONTROLLER_PORT, route)
self.sockets[0].sendto(packet, (CONTROLLER_IP, CONTROLLER_PORT))
def communicate(self):
while self.connected:
try:
server_port = 50003
if server_port not in self.server_dict:
self.server_dict[server_port] = 0
else:
self.server_dict[server_port] += 1
if self.server_dict[server_port] > MAX_SEQUENCE_NUMBER:
self.server_dict[server_port] = 0
sequence_number = self.server_dict[server_port]
message = bytes(str(sequence_number), "utf-8")
server_packet = packet_utils.create_packet(sequence_number, IP, 0, SERVER_IP, server_port, message)
gateway_packet = packet_utils.create_packet(sequence_number, IP, 0, GATEWAY_IP, GATEWAY_PORT,
server_packet)
acknowledged = False
while not acknowledged:
self.sock.sendall(gateway_packet)
try:
ready = select([self.sock], [], [], RETRY_TIMEOUT)
if ready[0]:
response_packet = self.sock.recv(BUFFER_SIZE)
unpacked = packet_utils.unpack(bytes(response_packet))
expected_next_sequence_number = unpacked.data
if int(expected_next_sequence_number) == int(sequence_number):
acknowledged = False
print("resending {}...".format(sequence_number))
else:
acknowledged = True
except ConnectionAbortedError:
print("Your connection has timed out, please restart the program.")
input("Press enter to quit")
break
except ConnectionResetError:
print("Your connection to the gateway has been lost, please restart the program.")
input("Press enter to quit")
break
def listen(self):
while True:
packet, address = self.sock.recvfrom(BUFFER_SIZE)
unpacked = packet_utils.unpack(packet)
packet_type = unpacked.packet_type
# router initialisation information
if packet_type == PACKET_TYPE_HELLO:
self.stable = False
neighbour_info = unpacked.data.split(",")
r_number = neighbour_info[0]
r_ip = unpacked.source_ip
r_port = unpacked.source_port
self.router_addresses[r_number] = (r_ip, r_port)
self.vertices.append(r_number)
self.edges[neighbour_info[0]] = {}
for i in range(1, len(neighbour_info)):
self.edges[neighbour_info[0]][neighbour_info[i]] = 1
# assume any non-ints are clients, catch clients and add them to list
try:
int(neighbour_info[i])
except ValueError:
self.client_list.append(neighbour_info[i])
self.vertices.append(neighbour_info[i])
self.edges[neighbour_info[i]] = {r_number: 1}
# route requests from routers
if packet_type == PACKET_TYPE_LINK_STATE_REQUEST:
route = unpacked.data
if route in self.route_table:
router_path = self.route_table[route]
else:
# reverse the route order and check again, return route in reverse
route = route[-2:] + "-" + route[:2]
if route in self.route_table:
router_path = self.route_table[route][::-1]
route = route[-2:] + "-" + route[:2]
print("\nController sending route information...")
print("{}: {}\n".format(route, router_path))
for i in range(len(router_path) - 1):
r_ip = self.router_addresses[str(router_path[i])][0]
r_port = self.router_addresses[str(router_path[i])][1]
target_router = str(router_path[i + 1])
destination = route[-2:]
info = bytes(destination + target_router, "utf-8")
packet = packet_utils.create_packet(0, PACKET_TYPE_LINK_STATE_UPDATE, CONTROLLER_IP,
CONTROLLER_PORT, r_ip, r_port, info)
self.sock.sendto(packet, (r_ip, r_port))
def send_messages(self):
while True:
message_out = bytes(input(""), "utf-8")
have_client = False
while not have_client:
destination = input("Select a Client by entering a number:\nBill[1], Carl[2], Dave[3], Eoin[4]:\n")
dest_client = 'E' + destination
if dest_client not in clients or dest_client == 'E0':
print("Error, try again.\n")
else:
have_client = True
packet = packet_utils.create_packet(0, PACKET_TYPE_CLIENT_MSG, self.host, self.port,
clients[dest_client][0], clients[dest_client][1], message_out)
self.sock.sendto(packet, self.router_address)
def listen(self, client, address):
size = BUFFER_SIZE
while True:
try:
packet = client.recv(size)
if packet:
print("RECEIVED PACKET FROM {}:{}".format(address[0], address[1]))
unpacked = packet_utils.unpack(packet)
client_packet = packet_utils.unpack(bytes(unpacked.data, "utf-8"))
sequence_number = client_packet.sequence_number
source_ip = address[0]
source_port = address[1]
destination_ip = client_packet.destination_ip
destination_port = client_packet.destination_port
data = bytes(client_packet.data, "utf-8")
print("DESTINATION: {}:{}".format(destination_ip, destination_port))
print("SEQUENCE NO.: {}".format(sequence_number))
server_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
try:
server_sock.connect((destination_ip, destination_port))
except ConnectionRefusedError:
print('ERROR: The connection was refused, is the server running?')
input("Press enter to quit")
server_packet = packet_utils.create_packet(sequence_number, source_ip, source_port, destination_ip,
destination_port, data)
packet_utils.to_string(server_packet)
print("forwarding to server...\n")
server_sock.sendall(server_packet)
server_response = server_sock.recv(BUFFER_SIZE)
unpacked = packet_utils.unpack(server_response)
data = unpacked.data
print("SERVER RESPONSE: {}\n".format(data))
client.sendall(server_response)
else:
client.close()
except:
client.close()
return
