class UDPTransport(Runnable):
UDP_MAX_MESSAGE_SIZE = 1200
log = log
log_healthcheck = log_healthcheck
def __init__(self, address, discovery, udpsocket, throttle_policy, config):
super().__init__()
# these values are initialized by the start method
self.queueids_to_queues: typing.Dict = dict()
self.raiden: RaidenService
self.message_handler: MessageHandler
self.discovery = discovery
self.config = config
self.address = address
self.retry_interval = config['retry_interval']
self.retries_before_backoff = config['retries_before_backoff']
self.nat_keepalive_retries = config['nat_keepalive_retries']
self.nat_keepalive_timeout = config['nat_keepalive_timeout']
self.nat_invitation_timeout = config['nat_invitation_timeout']
self.event_stop = Event()
self.event_stop.set()
self.greenlets = list()
self.addresses_events = dict()
self.messageids_to_asyncresults = dict()
# Maps the addresses to a dict with the latest nonce (using a dict
# because python integers are immutable)
self.nodeaddresses_to_nonces = dict()
cache = cachetools.TTLCache(
maxsize=50,
ttl=CACHE_TTL,
)
cache_wrapper = cachetools.cached(cache=cache)
self.get_host_port = cache_wrapper(discovery.get)
self.throttle_policy = throttle_policy
pool = gevent.pool.Pool()
self.server = DatagramServer(
udpsocket,
handle=self.receive,
spawn=pool,
)
def start(
self,
raiden_service: RaidenService,
message_handler: MessageHandler,
prev_auth_data: str,
):
if not self.event_stop.ready():
raise RuntimeError('UDPTransport started while running')
self.event_stop.clear()
self.raiden = raiden_service
self.log = log.bind(node=pex(self.raiden.address))
self.log_healthcheck = log_healthcheck.bind(node=pex(self.raiden.address))
self.message_handler = message_handler
# server.stop() clears the handle and the pool. Since this may be a
# restart the handle must always be set
self.server.set_handle(self.receive)
pool = gevent.pool.Pool()
self.server.set_spawn(pool)
self.server.start()
self.log.debug('UDP started')
super().start()
log.debug('UDP transport started')
def _run(self):
""" Runnable main method, perform wait on long-running subtasks """
try:
self.event_stop.wait()
except gevent.GreenletExit: # killed without exception
self.event_stop.set()
gevent.killall(self.greenlets) # kill children
raise # re-raise to keep killed status
except Exception:
self.stop() # ensure cleanup and wait on subtasks
raise
def stop(self):
if self.event_stop.ready():
return # double call, happens on normal stop, ignore
self.event_stop.set()
# Stop handling incoming packets, but don't close the socket. The
# socket can only be safely closed after all outgoing tasks are stopped
self.server.stop_accepting()
# Stop processing the outgoing queues
gevent.wait(self.greenlets)
# All outgoing tasks are stopped. Now it's safe to close the socket. At
# this point there might be some incoming message being processed,
# keeping the socket open is not useful for these.
self.server.stop()
# Calling `.close()` on a gevent socket doesn't actually close the underlying os socket
# so we do that ourselves here.
# See: https://github.com/gevent/gevent/blob/master/src/gevent/_socket2.py#L208
# and: https://groups.google.com/forum/#!msg/gevent/Ro8lRra3nH0/ZENgEXrr6M0J
try:
self.server._socket.close() # pylint: disable=protected-access
except socket.error:
pass
# Set all the pending results to False
for async_result in self.messageids_to_asyncresults.values():
async_result.set(False)
log.debug('UDP stopped', node=pex(self.raiden.address))
del self.log_healthcheck
del self.log
def get_health_events(self, recipient):
""" Starts a healthcheck task for `recipient` and returns a
HealthEvents with locks to react on its current state.
"""
if recipient not in self.addresses_events:
self.start_health_check(recipient)
return self.addresses_events[recipient]
def whitelist(self, address: typing.Address):
"""Whitelist peer address to receive communications from
This may be called before transport is started, to ensure events generated during
start are handled properly.
PS: udp currently doesn't do whitelisting, method defined for compatibility with matrix
"""
return
def start_health_check(self, recipient):
""" Starts a task for healthchecking `recipient` if there is not
one yet.
It also whitelists the address
"""
if recipient not in self.addresses_events:
self.whitelist(recipient) # noop for now, for compatibility
ping_nonce = self.nodeaddresses_to_nonces.setdefault(
recipient,
{'nonce': 0}, # HACK: Allows the task to mutate the object
)
events = healthcheck.HealthEvents(
event_healthy=Event(),
event_unhealthy=Event(),
)
self.addresses_events[recipient] = events
greenlet_healthcheck = gevent.spawn(
healthcheck.healthcheck,
self,
recipient,
self.event_stop,
events.event_healthy,
events.event_unhealthy,
self.nat_keepalive_retries,
self.nat_keepalive_timeout,
self.nat_invitation_timeout,
ping_nonce,
)
greenlet_healthcheck.name = f'Healthcheck for {pex(recipient)}'
greenlet_healthcheck.link_exception(self.on_error)
self.greenlets.append(greenlet_healthcheck)
def init_queue_for(
self,
queue_identifier: QueueIdentifier,
items: typing.List[QueueItem_T],
) -> Queue_T:
""" Create the queue identified by the queue_identifier
and initialize it with `items`.
"""
recipient = queue_identifier.recipient
queue = self.queueids_to_queues.get(queue_identifier)
assert queue is None
queue = NotifyingQueue(items=items)
self.queueids_to_queues[queue_identifier] = queue
events = self.get_health_events(recipient)
greenlet_queue = gevent.spawn(
single_queue_send,
self,
recipient,
queue,
queue_identifier,
self.event_stop,
events.event_healthy,
events.event_unhealthy,
self.retries_before_backoff,
self.retry_interval,
self.retry_interval * 10,
)
if queue_identifier.channel_identifier == CHANNEL_IDENTIFIER_GLOBAL_QUEUE:
greenlet_queue.name = f'Queue for {pex(recipient)} - global'
else:
greenlet_queue.name = (
f'Queue for {pex(recipient)} - {queue_identifier.channel_identifier}'
)
greenlet_queue.link_exception(self.on_error)
self.greenlets.append(greenlet_queue)
self.log.debug(
'new queue created for',
queue_identifier=queue_identifier,
items_qty=len(items),
)
return queue
def get_queue_for(
self,
queue_identifier: QueueIdentifier,
) -> Queue_T:
""" Return the queue identified by the given queue identifier.
If the queue doesn't exist it will be instantiated.
"""
queue = self.queueids_to_queues.get(queue_identifier)
if queue is None:
items = ()
queue = self.init_queue_for(queue_identifier, items)
return queue
def send_async(
self,
queue_identifier: QueueIdentifier,
message: Message,
):
""" Send a new ordered message to recipient.
Messages that use the same `queue_identifier` are ordered.
"""
recipient = queue_identifier.recipient
if not is_binary_address(recipient):
raise ValueError('Invalid address {}'.format(pex(recipient)))
# These are not protocol messages, but transport specific messages
if isinstance(message, (Delivered, Ping, Pong)):
raise ValueError('Do not use send for {} messages'.format(message.__class__.__name__))
messagedata = message.encode()
if len(messagedata) > self.UDP_MAX_MESSAGE_SIZE:
raise ValueError(
'message size exceeds the maximum {}'.format(self.UDP_MAX_MESSAGE_SIZE),
)
# message identifiers must be unique
message_id = message.message_identifier
# ignore duplicates
if message_id not in self.messageids_to_asyncresults:
self.messageids_to_asyncresults[message_id] = AsyncResult()
queue = self.get_queue_for(queue_identifier)
queue.put((messagedata, message_id))
assert queue.is_set()
self.log.debug(
'Message queued',
queue_identifier=queue_identifier,
queue_size=len(queue),
message=message,
)
def send_global(
self,
room: str,
message: Message,
) -> None:
""" This method exists only for interface compatibility with MatrixTransport """
self.log.warning('UDP is unable to send global messages. Ignoring')
def maybe_send(self, recipient: typing.Address, message: Message):
""" Send message to recipient if the transport is running. """
if not is_binary_address(recipient):
raise InvalidAddress('Invalid address {}'.format(pex(recipient)))
messagedata = message.encode()
host_port = self.get_host_port(recipient)
self.maybe_sendraw(host_port, messagedata)
def maybe_sendraw_with_result(
self,
recipient: typing.Address,
messagedata: bytes,
message_id: typing.MessageID,
) -> AsyncResult:
""" Send message to recipient if the transport is running.
Returns:
An AsyncResult that will be set once the message is delivered. As
long as the message has not been acknowledged with a Delivered
message the function will return the same AsyncResult.
"""
async_result = self.messageids_to_asyncresults.get(message_id)
if async_result is None:
async_result = AsyncResult()
self.messageids_to_asyncresults[message_id] = async_result
host_port = self.get_host_port(recipient)
self.maybe_sendraw(host_port, messagedata)
return async_result
def maybe_sendraw(self, host_port: typing.Tuple[int, int], messagedata: bytes):
""" Send message to recipient if the transport is running. """
# Don't sleep if timeout is zero, otherwise a context-switch is done
# and the message is delayed, increasing its latency
sleep_timeout = self.throttle_policy.consume(1)
if sleep_timeout:
gevent.sleep(sleep_timeout)
# Check the udp socket is still available before trying to send the
# message. There must be *no context-switches after this test*.
if hasattr(self.server, 'socket'):
self.server.sendto(
messagedata,
host_port,
)
def receive(
self,
messagedata: bytes,
host_port: typing.Tuple[str, int], # pylint: disable=unused-argument
) -> bool:
""" Handle an UDP packet. """
# pylint: disable=unidiomatic-typecheck
if len(messagedata) > self.UDP_MAX_MESSAGE_SIZE:
self.log.warning(
'Invalid message: Packet larger than maximum size',
message=encode_hex(messagedata),
length=len(messagedata),
)
return False
try:
message = decode(messagedata)
except InvalidProtocolMessage as e:
self.log.warning(
'Invalid protocol message',
error=str(e),
message=encode_hex(messagedata),
)
return False
if type(message) == Pong:
self.receive_pong(message)
elif type(message) == Ping:
self.receive_ping(message)
elif type(message) == Delivered:
self.receive_delivered(message)
elif message is not None:
self.receive_message(message)
else:
self.log.warning(
'Invalid message: Unknown cmdid',
message=encode_hex(messagedata),
)
return False
return True
def receive_message(self, message: Message):
""" Handle a Raiden protocol message.
The protocol requires durability of the messages. The UDP transport
relies on the node's WAL for durability. The message will be converted
to a state change, saved to the WAL, and *processed* before the
durability is confirmed, which is a stronger property than what is
required of any transport.
"""
self.raiden.on_message(message)
# Sending Delivered after the message is decoded and *processed*
# gives a stronger guarantee than what is required from a
# transport.
#
# Alternatives are, from weakest to strongest options:
# - Just save it on disk and asynchronously process the messages
# - Decode it, save to the WAL, and asynchronously process the
# state change
# - Decode it, save to the WAL, and process it (the current
# implementation)
delivered_message = Delivered(message.message_identifier)
self.raiden.sign(delivered_message)
self.maybe_send(
message.sender,
delivered_message,
)
def receive_delivered(self, delivered: Delivered):
""" Handle a Delivered message.
The Delivered message is how the UDP transport guarantees persistence
by the partner node. The message itself is not part of the raiden
protocol, but it's required by this transport to provide the required
properties.
"""
self.raiden.on_message(delivered)
message_id = delivered.delivered_message_identifier
async_result = self.raiden.transport.messageids_to_asyncresults.get(message_id)
# clear the async result, otherwise we have a memory leak
if async_result is not None:
del self.messageids_to_asyncresults[message_id]
async_result.set()
else:
self.log.warn(
'Unknown delivered message received',
message_id=message_id,
)
# Pings and Pongs are used to check the health status of another node. They
# are /not/ part of the raiden protocol, only part of the UDP transport,
# therefore these messages are not forwarded to the message handler.
def receive_ping(self, ping: Ping):
""" Handle a Ping message by answering with a Pong. """
self.log_healthcheck.debug(
'Ping received',
message_id=ping.nonce,
message=ping,
sender=pex(ping.sender),
)
pong = Pong(ping.nonce)
self.raiden.sign(pong)
try:
self.maybe_send(ping.sender, pong)
except (InvalidAddress, UnknownAddress) as e:
self.log.debug("Couldn't send the `Delivered` message", e=e)
def receive_pong(self, pong: Pong):
""" Handles a Pong message. """
message_id = ('ping', pong.nonce, pong.sender)
async_result = self.messageids_to_asyncresults.get(message_id)
if async_result is not None:
self.log_healthcheck.debug(
'Pong received',
sender=pex(pong.sender),
message_id=pong.nonce,
)
async_result.set(True)
else:
self.log_healthcheck.warn(
'Unknown pong received',
message_id=message_id,
)
def get_ping(self, nonce: int) -> Ping:
""" Returns a signed Ping message.
Note: Ping messages don't have an enforced ordering, so a Ping message
with a higher nonce may be acknowledged first.
"""
message = Ping(
nonce=nonce,
current_protocol_version=constants.PROTOCOL_VERSION,
)
self.raiden.sign(message)
message_data = message.encode()
return message_data
def set_node_network_state(self, node_address: typing.Address, node_state):
state_change = ActionChangeNodeNetworkState(node_address, node_state)
self.raiden.handle_state_change(state_change)
except ValueError:
continue
if (headers.get('x-user-agent', None) == 'redsonic'):
location = headers.get('location', None)
if location is not None and location not in CLIENTS:
print("Found WeMo at {0}".format(location))
CLIENTS[location] = headers
#gevent.spawn(discovered.send, self, address=address,
# headers=headers)
server = DatagramServer(get_ip_address() + ':54321', _response_received)
request = '\r\n'.join(
("M-SEARCH * HTTP/1.1", "HOST:{}:{}", "ST:upnp:rootdevice", "MX:2",
'MAN:"ssdp:discover"', "", "")).format(MCAST_IP, MCAST_PORT)
with gevent.Timeout(2, KeyboardInterrupt):
while True:
try:
server.set_spawn(1)
server.init_socket()
server.socket.setsockopt(_socket.IPPROTO_IP,
_socket.IP_MULTICAST_TTL, MCAST_TTL)
server.start()
server.sendto(request.encode(), (MCAST_IP, MCAST_PORT))
gevent.sleep(2)
except KeyboardInterrupt:
print('Scan Complete')
break
