def new_message_packet(message, source_server_address):
"""
Packet for sending a broadcast message to the whole network.
:param message: Our message
:param source_server_address: Server address of the packet sender.
:type message: str
:type source_server_address: tuple
:return: New Message packet.
:rtype: Packet
"""
p_version = 1
p_type = 4 # message packet
p_length = len(message)
p_ip, p_port = source_server_address
b_version = utils.int_to_bytes(p_version, 2)
b_type = utils.int_to_bytes(p_type, 2)
b_length = utils.int_to_bytes(p_length, 4)
b_ip = utils.ip_to_bytes(p_ip)
b_port = utils.int_to_bytes(int(p_port), 4)
header_bytes = b_version + b_type + b_length + b_ip + b_port
# Body
body = message
body_bytes = body.encode()
packet_bytes = bytearray(header_bytes + body_bytes)
return Packet(packet_bytes)
def new_join_packet(source_server_address):
"""
:param source_server_address: Server address of the packet sender.
:type source_server_address: tuple
:return New join packet.
:rtype Packet
"""
# Packet Header info
p_version = 1
p_type = 3 # advertise packet
p_length = 4
p_ip, p_port = source_server_address
b_version = utils.int_to_bytes(p_version, 2)
b_type = utils.int_to_bytes(p_type, 2)
b_length = utils.int_to_bytes(p_length, 4)
b_ip = utils.ip_to_bytes(p_ip)
b_port = utils.int_to_bytes(int(p_port), 4)
header_bytes = b_version + b_type + b_length + b_ip + b_port
body = 'JOIN'
body_bytes = body.encode()
packet_bytes = bytearray(header_bytes + body_bytes)
return Packet(packet_bytes)
def new_advertise_packet(type, source_server_address, neighbour=None):
"""
:param type: Type of Advertise packet
:param source_server_address Server address of the packet sender.
:param neighbour: The neighbour for advertise response packet; The format is like ('192.168.001.001', '05335').
:type type: str
:type source_server_address: tuple
:type neighbour: tuple
:return New advertise packet.
:rtype Packet
"""
# Packet Header info
p_version = 1
p_type = 2 # advertise packet
p_length = 3
if type == 'RES':
p_length = 3 + 20
elif type == 'REQ':
p_length = 3
p_ip, p_port = source_server_address
b_version = utils.int_to_bytes(p_version, 2)
b_type = utils.int_to_bytes(p_type, 2)
b_length = utils.int_to_bytes(p_length, 4)
b_ip = utils.ip_to_bytes(p_ip)
b_port = utils.int_to_bytes(int(p_port), 4)
header_bytes = b_version + b_type + b_length + b_ip + b_port
# packet body
body = ''
if type == 'RES':
body += type
if neighbour is not None:
body = body + neighbour[0] + neighbour[1]
else:
print(
"there's a problem... the neighbour address in the advertise response can't be None."
)
elif type == 'REQ':
body = type
body_bytes = body.encode()
packet_bytes = bytearray(header_bytes + body_bytes)
return Packet(packet_bytes)
def new_reunion_packet(type: str, source_address: (str, str),
nodes_array: list):
"""
:param type: Reunion Hello (REQ) or Reunion Hello Back (RES)
:param source_address: IP/Port address of the packet sender.
:param nodes_array: [(ip0, port0), (ip1, port1), ...] It is the path to the 'destination'.
:type type: str
:type source_address: tuple
:type nodes_array: list
:return New reunion packet.
:rtype Packet
"""
# Packet Header info
p_version = 1
p_type = 5 # reunion packet
p_length = 5 + 20 * len(nodes_array)
p_ip, p_port = source_address
b_version = utils.int_to_bytes(p_version, 2)
b_type = utils.int_to_bytes(p_type, 2)
b_length = utils.int_to_bytes(p_length, 4)
b_ip = utils.ip_to_bytes(p_ip)
b_port = utils.int_to_bytes(int(p_port), 4)
header_bytes = b_version + b_type + b_length + b_ip + b_port
number_of_entries = len(nodes_array)
p_num_of_entries = '{0:02d}'.format(number_of_entries)
# pack body
# fmt = '3s' + '2s'
# for i in range(number_of_entries):
# fmt += '15s' + '5s'
body = type + p_num_of_entries
# todo: double check this...
if type == 'REQ':
for i in range(len(nodes_array)):
body += nodes_array[i][0] + nodes_array[i][1]
elif type == 'RES':
for i in range(len(nodes_array) - 1, -1, -1):
body += nodes_array[i][0] + nodes_array[i][1]
body_bytes = body.encode()
packet_bytes = bytearray(header_bytes + body_bytes)
return Packet(packet_bytes)
def new_register_packet(type, source_server_address, address=(None, None)):
"""
:param type: Type of Register packet
:param source_server_address: Server address of the packet sender.
:param address: If 'type' is 'request' we need an address; The format is like ('192.168.001.001', '05335').
:type type: str
:type source_server_address: tuple
:type address: tuple
:return New Register packet.
:rtype Packet
"""
# Packet Header info
p_version = 1
p_type = 1 # register packet
p_length = 23
if type == 'REQ':
p_length = 3 + 20
elif type == 'RES':
p_length = 6
p_ip, p_port = source_server_address
b_version = utils.int_to_bytes(p_version, 2)
b_type = utils.int_to_bytes(p_type, 2)
b_length = utils.int_to_bytes(p_length, 4)
b_ip = utils.ip_to_bytes(p_ip)
b_port = utils.int_to_bytes(int(p_port), 4)
header_bytes = b_version + b_type + b_length + b_ip + b_port
# Body
body = type
if type == 'REQ':
if address is not None:
body = body + address[0] + address[1]
else:
print(
"there's a problem... the address in the register request can't be None."
)
elif type == 'RES':
body += 'ACK'
body_bytes = body.encode()
packet_bytes = bytearray(header_bytes + body_bytes)
return Packet(packet_bytes)
def get_buf(self):
"""
In this function, we will make our final buffer that represents the Packet with the Struct class methods.
:return The parsed packet to the network format.
:rtype: bytearray
"""
b_version = utils.int_to_bytes(self.version, 2)
b_type = utils.int_to_bytes(self.type, 2)
b_length = utils.int_to_bytes(self.length, 4)
b_ip = utils.ip_to_bytes(self.ip)
b_port = utils.int_to_bytes(int(self.port), 4)
b_body = self.body.encode()
if utils.DEBUG:
if bytearray(b_version + b_type + b_length + b_ip + b_port +
b_body) == self.buf:
print("DDD::U did it right! :))")
return bytearray(b_version + b_type + b_length + b_ip + b_port +
b_body)