class PTCServerProtocol(object):
def __init__(self, address, port):
self.state = CLOSED
self.control_block = ServerControlBlock(address, port)
self.socket = Soquete(address, port)
self.packet_builder = PacketBuilder(self)
self.connection_closed_event = threading.Event()
def is_connected(self):
return self.state == ESTABLISHED
def is_closed(self):
return self.state == CLOSED
def build_packet(self, flags=None):
ack = self.control_block.get_receive_seq()
packet = self.packet_builder.build(flags=flags, ack=ack)
return packet
def send_packet(self, packet):
self.socket.send(packet)
def receive(self, size):
if self.is_closed() and self.incoming_buffer.empty():
raise Exception('cannot receive: connection ended and no more pending data buffered')
elif self.incoming_buffer.empty() and not self.is_connected():
raise Exception('cannot receive: connection not established')
if size < MIN_PACKET_SIZE:
size = MIN_PACKET_SIZE
data = self.incoming_buffer.sync_get(MIN_PACKET_SIZE, size)
return data
def accept(self):
self.incoming_buffer = DataBuffer()
self.state = CLOSED
self.worker = ServerProtocolWorker.spawn_for(self)
self.worker.start()
# No hay mucho por hacer... simplemente esperar a que caiga el SYN del cliente
self.connected_event = threading.Event()
self.connected_event.wait()
def handle_incoming(self, packet):
seq_number = packet.get_seq_number()
if DEBUG: print 'recibi el paquete numero', seq_number
if SYNFlag in packet:
self.control_block.set_destination_address(packet.get_source_ip())
self.control_block.set_destination_port(packet.get_source_port())
self.control_block.set_receive_seq(seq_number)
ack_packet = self.build_packet(flags=[ACKFlag])
self.send_packet(ack_packet)
self.control_block.set_receive_seq(seq_number)
self.control_block.increment_receive_seq()
self.state = ESTABLISHED
self.connected_event.set()
if DEBUG: print 'server established'
if FINFlag in packet:
if self.control_block.accepts(seq_number):
if DEBUG: print 'server ended'
self.state = FIN_RECEIVED
self.send_ack()
self.close()
else:
data = packet.get_payload()
if DEBUG: print 'recibí un paquete con esta data:', data
if self.control_block.accepts(seq_number) and data:
self.incoming_buffer.put(data)
if self.state != FIN_RECEIVED:
self.send_ack()
self.control_block.increment_receive_seq()
def send_ack(self):
ack_packet = self.build_packet(flags=[ACKFlag])
self.send_packet(ack_packet)
def shutdown(self):
self.worker.stop()
# Esto es por si falló el establecimiento de conexión (para destrabar al thread principal)
self.connected_event.set()
def close(self):
self.state = CLOSED
self.connection_closed_event.set()
def wait_for_close(self):
self.connection_closed_event.wait()
class PTCServerProtocol(object):
def __init__(self, address, port):
self.state = CLOSED
self.control_block = ServerControlBlock(address, port)
self.socket = Soquete(address, port)
self.packet_builder = PacketBuilder(self)
self.connection_closed_event = threading.Event()
def is_connected(self):
return self.state == ESTABLISHED
def is_closed(self):
return self.state == CLOSED
def build_packet(self, flags=None):
ack = self.control_block.get_receive_seq()
packet = self.packet_builder.build(flags=flags, ack=ack)
return packet
def send_packet(self, packet):
self.socket.send(packet)
def receive(self, size):
if self.is_closed() and self.incoming_buffer.empty():
raise Exception('cannot receive: connection ended and no more pending data buffered')
elif self.incoming_buffer.empty() and not self.is_connected():
raise Exception('cannot receive: connection not established')
if size < MIN_PACKET_SIZE:
size = MIN_PACKET_SIZE
data = self.incoming_buffer.sync_get(MIN_PACKET_SIZE, size)
return data
def accept(self):
self.incoming_buffer = DataBuffer()
self.state = CLOSED
self.worker = ServerProtocolWorker.spawn_for(self)
self.worker.start()
# No hay mucho por hacer... simplemente esperar a que caiga el SYN del cliente
self.connected_event = threading.Event()
self.connected_event.wait()
def handle_incoming(self, packet):
seq_number = packet.get_seq_number()
if(debug):
print ("Recibi el paquete numero: "),
print (seq_number)
if SYNFlag in packet:
self.control_block.set_destination_address(packet.get_source_ip())
self.control_block.set_destination_port(packet.get_source_port())
self.control_block.set_receive_seq(seq_number)
ack_packet = self.build_packet(flags=[ACKFlag])
self.send_packet(ack_packet)
self.control_block.set_receive_seq(seq_number)
self.control_block.increment_receive_seq()
self.state = ESTABLISHED
self.connected_event.set()
if FINFlag in packet:
if self.control_block.accepts(seq_number):
self.state = FIN_RECEIVED
self.send_ack()
self.close()
else:
data = packet.get_payload()
if self.control_block.accepts(seq_number) and data:
self.incoming_buffer.put(data)
if self.state != FIN_RECEIVED:
self.send_ack()
self.control_block.increment_receive_seq()
def send_ack(self):
ack_packet = self.build_packet(flags=[ACKFlag])
self.send_packet(ack_packet)
def shutdown(self):
self.worker.stop()
# Esto es por si falló el establecimiento de conexión (para destrabar al thread principal)
self.connected_event.set()
def close(self):
self.state = CLOSED
self.connection_closed_event.set()
def wait_for_close(self):
self.connection_closed_event.wait()
