async def receive_handshake(
self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter
) -> None:
ip, socket, *_ = writer.get_extra_info("peername")
remote_address = Address(ip, socket)
if self.peer_pool.chk_dialin_blacklist(remote_address):
Logger.info_every_n(
"{} has been blacklisted, refusing connection".format(remote_address),
100,
)
reader.feed_eof()
writer.close()
expected_exceptions = (
TimeoutError,
PeerConnectionLost,
HandshakeFailure,
asyncio.IncompleteReadError,
HandshakeDisconnectedFailure,
)
try:
await self._receive_handshake(reader, writer)
except expected_exceptions as e:
self.logger.debug("Could not complete handshake: %s", e)
Logger.error_every_n("Could not complete handshake: {}".format(e), 100)
reader.feed_eof()
writer.close()
except OperationCancelled:
self.logger.error("OperationCancelled")
reader.feed_eof()
writer.close()
except Exception as e:
self.logger.exception("Unexpected error handling handshake")
reader.feed_eof()
writer.close()
async def _run(self) -> None:
self.logger.info("Running server...")
mapped_external_ip = None
if self.upnp_service:
mapped_external_ip = await self.upnp_service.add_nat_portmap()
external_ip = mapped_external_ip or "0.0.0.0"
await self._start_tcp_listener()
self.logger.info(
"this server: enode://%s@%s:%s",
self.privkey.public_key.to_hex()[2:],
external_ip,
self.port,
)
self.logger.info("network: %s", self.network_id)
self.logger.info("peers: max_peers=%s", self.max_peers)
addr = Address(external_ip, self.port, self.port)
if self.use_discv5:
topic = self._get_discv5_topic()
self.logger.info(
"Using experimental v5 (topic) discovery mechanism; topic: %s", topic
)
discovery_proto = DiscoveryByTopicProtocol(
topic,
self.privkey,
addr,
self.bootstrap_nodes,
self.network_id,
self.cancel_token,
)
else:
discovery_proto = PreferredNodeDiscoveryProtocol(
self.privkey,
addr,
self.bootstrap_nodes,
self.preferred_nodes,
self.network_id,
self.cancel_token,
)
self.discovery = DiscoveryService(
discovery_proto, self.peer_pool, self.port, token=self.cancel_token
)
self.run_daemon(self.peer_pool)
self.run_daemon(self.discovery)
if self.upnp_service:
# UPNP service is still experimental and not essential, so we don't use run_daemon() for
# it as that means if it crashes we'd be terminated as well.
self.run_child_service(self.upnp_service)
self.syncer = self._make_syncer()
await self.cancel_token.wait()
async def _receive_handshake(self, reader: asyncio.StreamReader,
writer: asyncio.StreamWriter) -> None:
msg = await self.wait(reader.read(ENCRYPTED_AUTH_MSG_LEN),
timeout=REPLY_TIMEOUT)
ip, socket, *_ = writer.get_extra_info("peername")
remote_address = Address(ip, socket)
self.logger.debug("Receiving handshake from %s", remote_address)
got_eip8 = False
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError:
# Try to decode as EIP8
got_eip8 = True
msg_size = big_endian_to_int(msg[:2])
remaining_bytes = msg_size - ENCRYPTED_AUTH_MSG_LEN + 2
msg += await self.wait(reader.read(remaining_bytes),
timeout=REPLY_TIMEOUT)
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError as e:
self.logger.debug("Failed to decrypt handshake: %s", e)
return
initiator_remote = Node(initiator_pubkey, remote_address)
responder = HandshakeResponder(initiator_remote, self.privkey,
got_eip8, self.cancel_token)
responder_nonce = numpy.random.bytes(HASH_LEN)
auth_ack_msg = responder.create_auth_ack_message(responder_nonce)
auth_ack_ciphertext = responder.encrypt_auth_ack_message(auth_ack_msg)
# Use the `writer` to send the reply to the remote
writer.write(auth_ack_ciphertext)
await self.wait(writer.drain())
# Call `HandshakeResponder.derive_shared_secrets()` and use return values to create `Peer`
aes_secret, mac_secret, egress_mac, ingress_mac = responder.derive_secrets(
initiator_nonce=initiator_nonce,
responder_nonce=responder_nonce,
remote_ephemeral_pubkey=ephem_pubkey,
auth_init_ciphertext=msg,
auth_ack_ciphertext=auth_ack_ciphertext,
)
connection = PeerConnection(
reader=reader,
writer=writer,
aes_secret=aes_secret,
mac_secret=mac_secret,
egress_mac=egress_mac,
ingress_mac=ingress_mac,
)
# Create and register peer in peer_pool
peer = self.peer_pool.get_peer_factory().create_peer(
remote=initiator_remote, connection=connection, inbound=True)
if self.peer_pool.is_full:
await peer.disconnect(DisconnectReason.too_many_peers)
return
elif not self.peer_pool.is_valid_connection_candidate(peer.remote):
await peer.disconnect(DisconnectReason.useless_peer)
return
total_peers = len(self.peer_pool)
inbound_peer_count = len([
peer for peer in self.peer_pool.connected_nodes.values()
if peer.inbound
])
if total_peers > 1 and inbound_peer_count / total_peers > DIAL_IN_OUT_RATIO:
# make sure to have at least 1/4 outbound connections
await peer.disconnect(DisconnectReason.too_many_peers)
else:
# We use self.wait() here as a workaround for
# https://github.com/ethereum/py-evm/issues/670.
await self.wait(self.do_handshake(peer))
async def _run(self) -> None:
self.logger.info("Running server...")
mapped_external_ip = None
if self.upnp_service:
mapped_external_ip = await self.upnp_service.add_nat_portmap()
external_ip = mapped_external_ip or "0.0.0.0"
await self._start_tcp_listener()
self.logger.info(
"this server: enode://%s@%s:%s",
self.privkey.public_key.to_hex()[2:],
external_ip,
self.port,
)
self.logger.info("network: %s", self.network_id)
self.logger.info("peers: max_peers=%s", self.max_peers)
addr = Address(external_ip, self.port, self.port)
if self.use_discv5:
topic = self._get_discv5_topic()
self.logger.info(
"Using experimental v5 (topic) discovery mechanism; topic: %s",
topic)
discovery_proto = DiscoveryByTopicProtocol(
topic,
self.privkey,
addr,
self.bootstrap_nodes,
self.network_id,
self.cancel_token,
)
else:
discovery_proto = PreferredNodeDiscoveryProtocol(
self.privkey,
addr,
self.bootstrap_nodes,
self.preferred_nodes,
self.network_id,
self.cancel_token,
)
routing_table_path = self.crawling_routing_table_path
if routing_table_path is not None:
assert (
platform.python_implementation() == "PyPy"
), "pytho3.6 on linux doesn't support pickling module objects"
self.discovery = CrawlingService(discovery_proto,
self.port,
token=self.cancel_token)
# hack: replace routing table
if (os.path.exists(routing_table_path)
and os.path.getsize(routing_table_path) > 0):
with open(routing_table_path, "rb") as f:
discovery_proto.routing = pickle.load(f)
discovery_proto.routing.this_node = discovery_proto.this_node
assert isinstance(discovery_proto.routing, RoutingTable)
def persist_routing_table(_):
with open(routing_table_path, "wb") as f:
pickle.dump(discovery_proto.routing, f)
self.discovery.add_finished_callback(persist_routing_table)
# no need to run peer pool as daemon
else:
self.discovery = DiscoveryService(discovery_proto,
self.peer_pool,
self.port,
token=self.cancel_token)
self.run_daemon(self.peer_pool)
self.run_daemon(self.discovery)
if self.upnp_service:
# UPNP service is still experimental and not essential, so we don't use run_daemon() for
# it as that means if it crashes we'd be terminated as well.
self.run_child_service(self.upnp_service)
self.syncer = self._make_syncer()
await self.cancel_token.wait()