def payload_is_accepted(self, packet):
seq_lo, seq_hi = packet.get_seq_interval()
first_byte, last_byte = seq_lo, seq_hi - 1
first_ok = SequenceNumber.a_leq_b_leq_c(self.rcv_nxt, first_byte,
self.rcv_nxt + self.rcv_wnd)
last_ok = SequenceNumber.a_leq_b_leq_c(self.rcv_nxt, last_byte,
self.rcv_nxt + self.rcv_wnd)
return last_byte >= first_byte and (first_ok or last_ok)
def payload_is_accepted(self, packet):
seq_lo, seq_hi = packet.get_seq_interval()
first_byte, last_byte = seq_lo, seq_hi-1
first_ok = SequenceNumber.a_leq_b_leq_c(self.rcv_nxt,
first_byte,
self.rcv_nxt+self.rcv_wnd)
last_ok = SequenceNumber.a_leq_b_leq_c(self.rcv_nxt, last_byte,
self.rcv_nxt+self.rcv_wnd)
return last_byte >= first_byte and (first_ok or last_ok)
def __init__(self):
self.source_port = 0
self.destination_port = 0
self.seq_number = SequenceNumber(0)
self.ack_number = SequenceNumber(0)
self.window_size = 0
self.flags = set()
self.payload = str()
self.parent = None
def __init__(self):
self.source_port = 0
self.destination_port = 0
self.seq_number = SequenceNumber(0)
self.ack_number = SequenceNumber(0)
self.window_size = 0
self.flags = set()
self.payload = str()
self.parent = None
def usable_window_size(self):
upper_limit = self.snd_una + self.snd_wnd
# If the upper window limit is below SND_NXT, we must return 0.
if SequenceNumber.a_leq_b_leq_c(self.snd_una, self.snd_nxt,
upper_limit):
return upper_limit - self.snd_nxt
else:
# TODO: add test!
return 0
def usable_window_size(self):
upper_limit = self.snd_una + self.snd_wnd
# Si el límite superior de la ventana está por debajo de SND_NXT,
# tenemos que devolver 0.
if SequenceNumber.a_leq_b_leq_c(self.snd_una, self.snd_nxt,
upper_limit):
return upper_limit - self.snd_nxt
else:
# TODO: agregar test!
return 0
def ack_is_accepted(self, ack_number):
# Aceptar sólo si SND_UNA < ACK <= SND_NXT
return SequenceNumber.a_lt_b_leq_c(self.snd_una, ack_number,
self.snd_nxt)
def ack_covers_tracked_packet(self, ack_number):
iss = self.protocol.iss
seq_number = self.tracked_packet.get_seq_number()
return SequenceNumber.a_leq_b_leq_c(iss, seq_number, ack_number)
def ack_is_accepted(self, ack_number):
# Aceptar sólo si SND_UNA < ACK <= SND_NXT
return SequenceNumber.a_lt_b_leq_c(self.snd_una, ack_number,
self.snd_nxt)
def compute_iss(self):
value = random.randint(0, MAX_SEQ)
return SequenceNumber(value)
def set_seq_number(self, seq_number):
self.seq_number = SequenceNumber(seq_number)
class PTCTransportPacket(object):
def __init__(self):
self.source_port = 0
self.destination_port = 0
self.seq_number = SequenceNumber(0)
self.ack_number = SequenceNumber(0)
self.window_size = 0
self.flags = set()
self.payload = str()
self.parent = None
def __contains__(self, element):
flag_contained = element in PTCFlag.__subclasses__() and\
element in self.get_flags()
return flag_contained
def get_source_port(self):
return self.source_port
def get_destination_port(self):
return self.destination_port
def get_seq_number(self):
return self.seq_number
def get_seq_interval(self):
seq_lo = self.seq_number.clone()
seq_hi = seq_lo + len(self.payload)
return seq_lo, seq_hi
def get_ack_number(self):
return self.ack_number
def get_window_size(self):
return self.window_size
def get_payload(self):
return self.payload
def get_parent(self):
return self.parent
def get_flags(self):
return self.flags
def add_flag(self, flag):
self.flags.add(flag)
def add_flags(self, flags):
self.flags.update(flags)
def set_source_port(self, port):
self.source_port = port
def set_destination_port(self, port):
self.destination_port = port
def set_seq_number(self, seq_number):
self.seq_number = SequenceNumber(seq_number)
def set_ack_number(self, ack_number):
self.ack_number = SequenceNumber(ack_number)
def set_window_size(self, window_size):
self.window_size = window_size % (MAX_WND+1)
def set_payload(self, data):
self.payload = data
if self.parent is not None:
length_difference = len(data) - len(self.payload)
self.parent.add_length(length_difference)
def set_parent(self, parent):
self.parent = parent
def has_payload(self):
return len(self.payload) > 0
def get_bytes(self):
flags_bytes = reduce(lambda value, flag: value ^ flag.get_bits(),
self.flags, 0)
header_bytes = struct.pack('!HHLLHH', self.source_port,
self.destination_port,
self.seq_number,
self.ack_number,
flags_bytes,
self.window_size)
return header_bytes + self.payload
def should_update_window(self, ack_number):
# TODO: add tests for this.
# RFC 1122, p.94 (correction to RFC 793).
return SequenceNumber.a_leq_b_leq_c(self.snd_una, ack_number,
self.snd_nxt)
def should_update_window(self, ack_number):
# TODO: agregar tests para esto.
# RFC 1122, p.94 (corrección al RFC 793).
return SequenceNumber.a_leq_b_leq_c(self.snd_una, ack_number,
self.snd_nxt)
def set_ack_number(self, ack_number):
self.ack_number = SequenceNumber(ack_number)
class PTCTransportPacket(object):
def __init__(self):
self.source_port = 0
self.destination_port = 0
self.seq_number = SequenceNumber(0)
self.ack_number = SequenceNumber(0)
self.window_size = 0
self.flags = set()
self.payload = str()
self.parent = None
def __contains__(self, element):
flag_contained = element in PTCFlag.__subclasses__() and\
element in self.get_flags()
return flag_contained
def get_source_port(self):
return self.source_port
def get_destination_port(self):
return self.destination_port
def get_seq_number(self):
return self.seq_number
def get_seq_interval(self):
seq_lo = self.seq_number.clone()
seq_hi = seq_lo + len(self.payload)
return seq_lo, seq_hi
def get_ack_number(self):
return self.ack_number
def get_window_size(self):
return self.window_size
def get_payload(self):
return self.payload
def get_parent(self):
return self.parent
def get_flags(self):
return self.flags
def add_flag(self, flag):
self.flags.add(flag)
def add_flags(self, flags):
self.flags.update(flags)
def set_source_port(self, port):
self.source_port = port
def set_destination_port(self, port):
self.destination_port = port
def set_seq_number(self, seq_number):
self.seq_number = SequenceNumber(seq_number)
def set_ack_number(self, ack_number):
self.ack_number = SequenceNumber(ack_number)
def set_window_size(self, window_size):
self.window_size = window_size % (MAX_WND+1)
def set_payload(self, data):
self.payload = data
if self.parent is not None:
length_difference = len(data) - len(self.payload)
self.parent.add_length(length_difference)
def set_parent(self, parent):
self.parent = parent
def has_payload(self):
return len(self.payload) > 0
def get_bytes(self):
flags_bytes = reduce(lambda value, flag: value ^ flag.get_bits(),
self.flags, 0)
header_bytes = struct.pack('!HHLLHH', self.source_port,
self.destination_port,
self.seq_number,
self.ack_number,
flags_bytes,
self.window_size)
return header_bytes + self.payload
def should_update_window(self, ack_number):
# TODO: agregar tests para esto.
# RFC 1122, p.94 (corrección al RFC 793).
return SequenceNumber.a_leq_b_leq_c(self.snd_una, ack_number,
self.snd_nxt)
def set_seq_number(self, seq_number):
self.seq_number = SequenceNumber(seq_number)
def ack_covers_tracked_packet(self, ack_number):
iss = self.protocol.iss
seq_number = self.tracked_packet.get_seq_number()
return SequenceNumber.a_leq_b_leq_c(iss, seq_number, ack_number)