class Node(BaseService):
_is_started: bool = False
key_pair: KeyPair
listen_ip: str
listen_port: int
host: BasicHost
pubsub: Pubsub
bootstrap_nodes: Optional[Tuple[Multiaddr, ...]]
preferred_nodes: Optional[Tuple[Multiaddr, ...]]
chain: BaseBeaconChain
handshaked_peers: PeerPool = None
def __init__(
self,
key_pair: KeyPair,
listen_ip: str,
listen_port: int,
chain: BaseBeaconChain,
security_protocol_ops: Dict[TProtocol, BaseSecureTransport] = None,
muxer_protocol_ops: Dict[TProtocol, IMuxedConn] = None,
gossipsub_params: Optional[GossipsubParams] = None,
cancel_token: CancelToken = None,
bootstrap_nodes: Tuple[Multiaddr, ...] = None,
preferred_nodes: Tuple[Multiaddr, ...] = None) -> None:
super().__init__(cancel_token)
self.listen_ip = listen_ip
self.listen_port = listen_port
self.key_pair = key_pair
self.bootstrap_nodes = bootstrap_nodes
self.preferred_nodes = preferred_nodes
# TODO: Add key and peer_id to the peerstore
if security_protocol_ops is None:
security_protocol_ops = {
PLAINTEXT_PROTOCOL_ID: InsecureTransport(key_pair)
}
if muxer_protocol_ops is None:
muxer_protocol_ops = {MPLEX_PROTOCOL_ID: Mplex}
network: INetwork = initialize_default_swarm(
key_pair=key_pair,
transport_opt=[self.listen_maddr],
muxer_opt=muxer_protocol_ops,
sec_opt=security_protocol_ops,
peerstore_opt=None, # let the function initialize it
disc_opt=None, # no routing required here
)
self.host = BasicHost(network=network, router=None)
if gossipsub_params is None:
gossipsub_params = GossipsubParams()
gossipsub_router = GossipSub(
protocols=[GOSSIPSUB_PROTOCOL_ID],
degree=gossipsub_params.DEGREE,
degree_low=gossipsub_params.DEGREE_LOW,
degree_high=gossipsub_params.DEGREE_HIGH,
time_to_live=gossipsub_params.FANOUT_TTL,
gossip_window=gossipsub_params.GOSSIP_WINDOW,
gossip_history=gossipsub_params.GOSSIP_HISTORY,
heartbeat_interval=gossipsub_params.HEARTBEAT_INTERVAL,
)
self.pubsub = Pubsub(
host=self.host,
router=gossipsub_router,
my_id=self.peer_id,
)
self.chain = chain
self.handshaked_peers = PeerPool()
self.run_task(self.start())
@property
def is_started(self) -> bool:
return self._is_started
async def _run(self) -> None:
self.logger.info("libp2p node %s is up", self.listen_maddr)
await self.cancellation()
async def start(self) -> None:
# host
self._register_rpc_handlers()
# TODO: Register notifees
await self.host.get_network().listen(self.listen_maddr)
await self.connect_preferred_nodes()
# TODO: Connect bootstrap nodes?
# pubsub
await self.pubsub.subscribe(PUBSUB_TOPIC_BEACON_BLOCK)
await self.pubsub.subscribe(PUBSUB_TOPIC_BEACON_ATTESTATION)
self._setup_topic_validators()
self._is_started = True
def _setup_topic_validators(self) -> None:
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_BEACON_BLOCK,
get_beacon_block_validator(self.chain),
False,
)
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_BEACON_ATTESTATION,
get_beacon_attestation_validator(self.chain),
False,
)
async def dial_peer(self, ip: str, port: int, peer_id: ID) -> None:
"""
Dial the peer ``peer_id`` through the IPv4 protocol
"""
await self.host.connect(
PeerInfo(
peer_id=peer_id,
addrs=[make_tcp_ip_maddr(ip, port)],
)
)
async def dial_peer_maddr(self, maddr: Multiaddr) -> None:
"""
Parse `maddr`, get the ip:port and PeerID, and call `dial_peer` with the parameters.
"""
ip = maddr.value_for_protocol(protocols.P_IP4)
port = maddr.value_for_protocol(protocols.P_TCP)
peer_id = ID.from_base58(maddr.value_for_protocol(protocols.P_P2P))
await self.dial_peer(ip=ip, port=port, peer_id=peer_id)
async def connect_preferred_nodes(self) -> None:
if self.preferred_nodes is None or len(self.preferred_nodes) == 0:
return
await asyncio.wait([
self.dial_peer_maddr(node_maddr)
for node_maddr in self.preferred_nodes
])
async def disconnect_peer(self, peer_id: ID) -> None:
if peer_id in self.handshaked_peers:
self.logger.debug("Disconnect from %s", peer_id)
self.handshaked_peers.remove(peer_id)
await self.host.disconnect(peer_id)
else:
self.logger.debug("Already disconnected from %s", peer_id)
async def broadcast_beacon_block(self, block: BaseBeaconBlock) -> None:
await self._broadcast_data(PUBSUB_TOPIC_BEACON_BLOCK, ssz.encode(block))
async def broadcast_attestation(self, attestation: Attestation) -> None:
await self._broadcast_data(PUBSUB_TOPIC_BEACON_ATTESTATION, ssz.encode(attestation))
async def _broadcast_data(self, topic: str, data: bytes) -> None:
await self.pubsub.publish(topic, data)
@property
def peer_id(self) -> ID:
return self.host.get_id()
@property
def listen_maddr(self) -> Multiaddr:
return make_tcp_ip_maddr(self.listen_ip, self.listen_port)
@property
def listen_maddr_with_peer_id(self) -> Multiaddr:
return self.listen_maddr.encapsulate(Multiaddr(f"/p2p/{self.peer_id.to_base58()}"))
@property
def peer_store(self) -> PeerStore:
return self.host.get_network().peerstore
async def close(self) -> None:
# FIXME: Add `tear_down` to `Swarm` in the upstream
network = self.host.get_network()
for listener in network.listeners.values():
listener.server.close()
await listener.server.wait_closed()
# TODO: Add `close` in `Pubsub`
def _register_rpc_handlers(self) -> None:
self.host.set_stream_handler(REQ_RESP_HELLO_SSZ, self._handle_hello)
self.host.set_stream_handler(REQ_RESP_GOODBYE_SSZ, self._handle_goodbye)
self.host.set_stream_handler(REQ_RESP_BEACON_BLOCKS_SSZ, self._handle_beacon_blocks)
self.host.set_stream_handler(
REQ_RESP_RECENT_BEACON_BLOCKS_SSZ,
self._handle_recent_beacon_blocks,
)
#
# RPC Handlers
#
# TODO: Add a wrapper or decorator to handle the exceptions in handlers,
# to close the streams safely. Probably starting from: if the function
# returns successfully, then close the stream. Otherwise, reset the stream.
# TODO: Handle the reputation of peers. Deduct their scores and even disconnect when they
# behave.
# TODO: Register notifee to the `Network` to
# - Record peers' joining time.
# - Disconnect peers when they fail to join in a certain amount of time.
async def _validate_hello_req(self, hello_other_side: HelloRequest) -> None:
state_machine = self.chain.get_state_machine()
state = self.chain.get_head_state()
config = state_machine.config
if hello_other_side.fork_version != state.fork.current_version:
raise ValidationError(
"`fork_version` mismatches: "
f"hello_other_side.fork_version={hello_other_side.fork_version}, "
f"state.fork.current_version={state.fork.current_version}"
)
# Can not validate the checkpoint with `finalized_epoch` higher than ours
if hello_other_side.finalized_epoch > state.finalized_checkpoint.epoch:
return
# Get the finalized root at `hello_other_side.finalized_epoch`
# Edge case where nothing is finalized yet
if (
hello_other_side.finalized_epoch == 0 and
hello_other_side.finalized_root == ZERO_SIGNING_ROOT
):
return
finalized_epoch_start_slot = compute_start_slot_of_epoch(
hello_other_side.finalized_epoch,
config.SLOTS_PER_EPOCH,
)
finalized_root = self.chain.get_canonical_block_root(
finalized_epoch_start_slot)
if hello_other_side.finalized_root != finalized_root:
raise ValidationError(
"`finalized_root` mismatches: "
f"hello_other_side.finalized_root={hello_other_side.finalized_root}, "
f"hello_other_side.finalized_epoch={hello_other_side.finalized_epoch}, "
f"our `finalized_root` at the same `finalized_epoch`={finalized_root}"
)
def _make_hello_packet(self) -> HelloRequest:
state = self.chain.get_head_state()
head = self.chain.get_canonical_head()
finalized_checkpoint = state.finalized_checkpoint
return HelloRequest(
fork_version=state.fork.current_version,
finalized_root=finalized_checkpoint.root,
finalized_epoch=finalized_checkpoint.epoch,
head_root=head.hash_tree_root,
head_slot=head.slot,
)
def _compare_chain_tip_and_finalized_epoch(self,
peer_finalized_epoch: Epoch,
peer_head_slot: Slot) -> None:
checkpoint = self.chain.get_head_state().finalized_checkpoint
head_block = self.chain.get_canonical_head()
peer_has_higher_finalized_epoch = peer_finalized_epoch > checkpoint.epoch
peer_has_equal_finalized_epoch = peer_finalized_epoch == checkpoint.epoch
peer_has_higher_head_slot = peer_head_slot > head_block.slot
if (
peer_has_higher_finalized_epoch or
(peer_has_equal_finalized_epoch and peer_has_higher_head_slot)
):
# TODO: kickoff syncing process with this peer
self.logger.debug("Peer's chain is ahead of us, start syncing with the peer.")
pass
async def _handle_hello(self, stream: INetStream) -> None:
# TODO: Find out when we should respond the `ResponseCode`
# other than `ResponseCode.SUCCESS`.
peer_id = stream.mplex_conn.peer_id
self.logger.debug("Waiting for hello from the other side")
try:
hello_other_side = await read_req(stream, HelloRequest)
has_error = False
except (ReadMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, ReadMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
await self.disconnect_peer(peer_id)
return
self.logger.debug("Received the hello message %s", hello_other_side)
try:
await self._validate_hello_req(hello_other_side)
except ValidationError as error:
self.logger.info(
"Handshake failed: hello message %s is invalid: %s",
hello_other_side,
str(error)
)
await stream.reset()
await self.say_goodbye(peer_id, GoodbyeReasonCode.IRRELEVANT_NETWORK)
await self.disconnect_peer(peer_id)
return
hello_mine = self._make_hello_packet()
self.logger.debug("Sending our hello message %s", hello_mine)
try:
await write_resp(stream, hello_mine, ResponseCode.SUCCESS)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
self.logger.info(
"Handshake failed: failed to write message %s",
hello_mine,
)
await self.disconnect_peer(peer_id)
return
if peer_id not in self.handshaked_peers:
peer = Peer.from_hello_request(self, peer_id, hello_other_side)
self.handshaked_peers.add(peer)
self.logger.debug(
"Handshake from %s is finished. Added to the `handshake_peers`",
peer_id,
)
# Check if we are behind the peer
self._compare_chain_tip_and_finalized_epoch(
hello_other_side.finalized_epoch,
hello_other_side.head_slot,
)
await stream.close()
async def say_hello(self, peer_id: ID) -> None:
hello_mine = self._make_hello_packet()
self.logger.debug(
"Opening new stream to peer=%s with protocols=%s",
peer_id,
[REQ_RESP_HELLO_SSZ],
)
stream = await self.host.new_stream(peer_id, [REQ_RESP_HELLO_SSZ])
self.logger.debug("Sending our hello message %s", hello_mine)
try:
await write_req(stream, hello_mine)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
await self.disconnect_peer(peer_id)
error_msg = f"fail to write request={hello_mine}"
self.logger.info("Handshake failed: %s", error_msg)
raise HandshakeFailure(error_msg)
self.logger.debug("Waiting for hello from the other side")
try:
resp_code, hello_other_side = await read_resp(stream, HelloRequest)
has_error = False
except (ReadMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, ReadMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
await self.disconnect_peer(peer_id)
self.logger.info("Handshake failed: fail to read the response")
raise HandshakeFailure("fail to read the response")
self.logger.debug(
"Received the hello message %s, resp_code=%s",
hello_other_side,
resp_code,
)
# TODO: Handle the case when `resp_code` is not success.
if resp_code != ResponseCode.SUCCESS:
# TODO: Do something according to the `ResponseCode`
error_msg = (
"resp_code != ResponseCode.SUCCESS, "
f"resp_code={resp_code}, error_msg={hello_other_side}"
)
self.logger.info("Handshake failed: %s", error_msg)
await stream.reset()
await self.disconnect_peer(peer_id)
raise HandshakeFailure(error_msg)
hello_other_side = cast(HelloRequest, hello_other_side)
try:
await self._validate_hello_req(hello_other_side)
except ValidationError as error:
error_msg = f"hello message {hello_other_side} is invalid: {str(error)}"
self.logger.info(
"Handshake failed: %s. Disconnecting %s",
error_msg,
peer_id,
)
await stream.reset()
await self.say_goodbye(peer_id, GoodbyeReasonCode.IRRELEVANT_NETWORK)
await self.disconnect_peer(peer_id)
raise HandshakeFailure(error_msg) from error
if peer_id not in self.handshaked_peers:
peer = Peer.from_hello_request(self, peer_id, hello_other_side)
self.handshaked_peers.add(peer)
self.logger.debug(
"Handshake to peer=%s is finished. Added to the `handshake_peers`",
peer_id,
)
# Check if we are behind the peer
self._compare_chain_tip_and_finalized_epoch(
hello_other_side.finalized_epoch,
hello_other_side.head_slot,
)
await stream.close()
async def _handle_goodbye(self, stream: INetStream) -> None:
peer_id = stream.mplex_conn.peer_id
self.logger.debug("Waiting for goodbye from %s", peer_id)
try:
goodbye = await read_req(stream, Goodbye)
has_error = False
except (ReadMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, ReadMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
self.logger.debug("Received the goodbye message %s", goodbye)
if not has_error:
await stream.close()
await self.disconnect_peer(peer_id)
async def say_goodbye(self, peer_id: ID, reason: GoodbyeReasonCode) -> None:
goodbye = Goodbye(reason)
self.logger.debug(
"Opening new stream to peer=%s with protocols=%s",
peer_id,
[REQ_RESP_GOODBYE_SSZ],
)
stream = await self.host.new_stream(peer_id, [REQ_RESP_GOODBYE_SSZ])
self.logger.debug("Sending our goodbye message %s", goodbye)
try:
await write_req(stream, goodbye)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
if not has_error:
await stream.close()
await self.disconnect_peer(peer_id)
@to_tuple
def _get_blocks_from_canonical_chain_by_slot(
self,
slot_of_requested_blocks: Sequence[Slot],
) -> Iterable[BaseBeaconBlock]:
# If peer's head block is on our canonical chain,
# start getting the requested blocks by slots.
for slot in slot_of_requested_blocks:
try:
block = self.chain.get_canonical_block_by_slot(slot)
except BlockNotFound:
pass
else:
yield block
@to_tuple
def _get_blocks_from_fork_chain_by_root(
self,
start_slot: Slot,
peer_head_block: BaseBeaconBlock,
slot_of_requested_blocks: Sequence[Slot],
) -> Iterable[BaseBeaconBlock]:
# Peer's head block is on a fork chain,
# start getting the requested blocks by
# traversing the history from the head.
# `slot_of_requested_blocks` starts with earliest slot
# and end with most recent slot, so we start traversing
# from the most recent slot.
cur_index = len(slot_of_requested_blocks) - 1
block = peer_head_block
if block.slot == slot_of_requested_blocks[cur_index]:
yield block
cur_index -= 1
while block.slot > start_slot and cur_index >= 0:
try:
block = self.chain.get_block_by_root(block.parent_root)
except (BlockNotFound, ValidationError):
# This should not happen as we only persist block if its
# ancestors are also in the database.
break
else:
while block.slot < slot_of_requested_blocks[cur_index]:
if cur_index > 0:
cur_index -= 1
else:
break
if block.slot == slot_of_requested_blocks[cur_index]:
yield block
def _validate_start_slot(self, start_slot: Slot) -> None:
config = self.chain.get_state_machine().config
state = self.chain.get_head_state()
finalized_epoch_start_slot = compute_start_slot_of_epoch(
epoch=state.finalized_checkpoint.epoch,
slots_per_epoch=config.SLOTS_PER_EPOCH,
)
if start_slot < finalized_epoch_start_slot:
raise ValidationError(
f"`start_slot`({start_slot}) lower than our"
f" latest finalized slot({finalized_epoch_start_slot})"
)
def _get_requested_beacon_blocks(
self,
beacon_blocks_request: BeaconBlocksRequest,
requested_head_block: BaseBeaconBlock,
) -> Tuple[BaseBeaconBlock, ...]:
slot_of_requested_blocks = tuple(
beacon_blocks_request.start_slot + i * beacon_blocks_request.step
for i in range(beacon_blocks_request.count)
)
self.logger.info("slot_of_requested_blocks: %s", slot_of_requested_blocks)
slot_of_requested_blocks = tuple(
filter(lambda slot: slot <= requested_head_block.slot, slot_of_requested_blocks)
)
if len(slot_of_requested_blocks) == 0:
return tuple()
# We have the peer's head block in our database,
# next check if the head block is on our canonical chain.
try:
canonical_block_at_slot = self.chain.get_canonical_block_by_slot(
requested_head_block.slot
)
block_match = canonical_block_at_slot == requested_head_block
except BlockNotFound:
self.logger.debug(
(
"The requested head block is not on our canonical chain "
"requested_head_block: %s canonical_block_at_slot: %s"
),
requested_head_block,
canonical_block_at_slot,
)
block_match = False
finally:
if block_match:
# Peer's head block is on our canonical chain
return self._get_blocks_from_canonical_chain_by_slot(
slot_of_requested_blocks
)
else:
# Peer's head block is not on our canonical chain
# Validate `start_slot` is greater than our latest finalized slot
self._validate_start_slot(beacon_blocks_request.start_slot)
return self._get_blocks_from_fork_chain_by_root(
beacon_blocks_request.start_slot,
requested_head_block,
slot_of_requested_blocks,
)
async def _handle_beacon_blocks(self, stream: INetStream) -> None:
peer_id = stream.mplex_conn.peer_id
if peer_id not in self.handshaked_peers:
self.logger.info(
"Processing beacon blocks request failed: not handshaked with peer=%s yet",
peer_id,
)
await stream.reset()
return
self.logger.debug("Waiting for beacon blocks request from the other side")
try:
beacon_blocks_request = await read_req(stream, BeaconBlocksRequest)
has_error = False
except (ReadMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, ReadMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
return
self.logger.debug("Received the beacon blocks request message %s", beacon_blocks_request)
try:
requested_head_block = self.chain.get_block_by_hash_tree_root(
beacon_blocks_request.head_block_root
)
except (BlockNotFound, ValidationError) as error:
self.logger.info("Sending empty blocks, reason: %s", error)
# We don't have the chain data peer is requesting
requested_beacon_blocks: Tuple[BaseBeaconBlock, ...] = tuple()
else:
# Check if slot of specified head block is greater than specified start slot
if requested_head_block.slot < beacon_blocks_request.start_slot:
reason = (
f"Invalid request: head block slot({requested_head_block.slot})"
f" lower than `start_slot`({beacon_blocks_request.start_slot})"
)
try:
await write_resp(stream, reason, ResponseCode.INVALID_REQUEST)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
self.logger.info(
"Processing beacon blocks request failed: failed to write message %s",
reason,
)
return
await stream.close()
return
else:
try:
requested_beacon_blocks = self._get_requested_beacon_blocks(
beacon_blocks_request, requested_head_block
)
except ValidationError as val_error:
reason = "Invalid request: " + str(val_error)
try:
await write_resp(stream, reason, ResponseCode.INVALID_REQUEST)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
self.logger.info(
"Processing beacon blocks request failed: "
"failed to write message %s",
reason,
)
return
await stream.close()
return
# TODO: Should it be a successful response if peer is requesting
# blocks on a fork we don't have data for?
beacon_blocks_response = BeaconBlocksResponse(blocks=requested_beacon_blocks)
self.logger.debug("Sending beacon blocks response %s", beacon_blocks_response)
try:
await write_resp(stream, beacon_blocks_response, ResponseCode.SUCCESS)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
self.logger.info(
"Processing beacon blocks request failed: failed to write message %s",
beacon_blocks_response,
)
return
self.logger.debug(
"Processing beacon blocks request from %s is finished",
peer_id,
)
await stream.close()
async def request_beacon_blocks(self,
peer_id: ID,
head_block_root: HashTreeRoot,
start_slot: Slot,
count: int,
step: int) -> Tuple[BaseBeaconBlock, ...]:
if peer_id not in self.handshaked_peers:
error_msg = f"not handshaked with peer={peer_id} yet"
self.logger.info("Request beacon block failed: %s", error_msg)
raise RequestFailure(error_msg)
beacon_blocks_request = BeaconBlocksRequest(
head_block_root=head_block_root,
start_slot=start_slot,
count=count,
step=step,
)
self.logger.debug(
"Opening new stream to peer=%s with protocols=%s",
peer_id,
[REQ_RESP_BEACON_BLOCKS_SSZ],
)
stream = await self.host.new_stream(peer_id, [REQ_RESP_BEACON_BLOCKS_SSZ])
self.logger.debug("Sending beacon blocks request %s", beacon_blocks_request)
try:
await write_req(stream, beacon_blocks_request)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
error_msg = f"fail to write request={beacon_blocks_request}"
self.logger.info("Request beacon blocks failed: %s", error_msg)
raise RequestFailure(error_msg)
self.logger.debug("Waiting for beacon blocks response")
try:
resp_code, beacon_blocks_response = await read_resp(stream, BeaconBlocksResponse)
has_error = False
except (ReadMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, ReadMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
self.logger.info("Request beacon blocks failed: fail to read the response")
raise RequestFailure("fail to read the response")
self.logger.debug(
"Received beacon blocks response %s, resp_code=%s",
beacon_blocks_response,
resp_code,
)
if resp_code != ResponseCode.SUCCESS:
error_msg = (
"resp_code != ResponseCode.SUCCESS, "
f"resp_code={resp_code}, error_msg={beacon_blocks_response}"
)
self.logger.info("Request beacon blocks failed: %s", error_msg)
await stream.reset()
raise RequestFailure(error_msg)
await stream.close()
beacon_blocks_response = cast(BeaconBlocksResponse, beacon_blocks_response)
return beacon_blocks_response.blocks
async def _handle_recent_beacon_blocks(self, stream: INetStream) -> None:
peer_id = stream.mplex_conn.peer_id
if peer_id not in self.handshaked_peers:
self.logger.info(
"Processing recent beacon blocks request failed: not handshaked with peer=%s yet",
peer_id,
)
await stream.reset()
return
self.logger.debug("Waiting for recent beacon blocks request from the other side")
try:
recent_beacon_blocks_request = await read_req(stream, RecentBeaconBlocksRequest)
has_error = False
except (ReadMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, ReadMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
return
self.logger.debug(
"Received the recent beacon blocks request message %s",
recent_beacon_blocks_request,
)
recent_beacon_blocks = []
for block_root in recent_beacon_blocks_request.block_roots:
try:
block = self.chain.get_block_by_hash_tree_root(block_root)
except (BlockNotFound, ValidationError):
pass
else:
recent_beacon_blocks.append(block)
recent_beacon_blocks_response = RecentBeaconBlocksResponse(blocks=recent_beacon_blocks)
self.logger.debug("Sending recent beacon blocks response %s", recent_beacon_blocks_response)
try:
await write_resp(stream, recent_beacon_blocks_response, ResponseCode.SUCCESS)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
self.logger.info(
"Processing recent beacon blocks request failed: failed to write message %s",
recent_beacon_blocks_response,
)
return
self.logger.debug(
"Processing recent beacon blocks request from %s is finished",
peer_id,
)
await stream.close()
async def request_recent_beacon_blocks(
self,
peer_id: ID,
block_roots: Sequence[HashTreeRoot]) -> Tuple[BaseBeaconBlock, ...]:
if peer_id not in self.handshaked_peers:
error_msg = f"not handshaked with peer={peer_id} yet"
self.logger.info("Request recent beacon block failed: %s", error_msg)
raise RequestFailure(error_msg)
recent_beacon_blocks_request = RecentBeaconBlocksRequest(block_roots=block_roots)
self.logger.debug(
"Opening new stream to peer=%s with protocols=%s",
peer_id,
[REQ_RESP_RECENT_BEACON_BLOCKS_SSZ],
)
stream = await self.host.new_stream(peer_id, [REQ_RESP_RECENT_BEACON_BLOCKS_SSZ])
self.logger.debug("Sending recent beacon blocks request %s", recent_beacon_blocks_request)
try:
await write_req(stream, recent_beacon_blocks_request)
has_error = False
except (WriteMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, WriteMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
error_msg = f"fail to write request={recent_beacon_blocks_request}"
self.logger.info("Request recent beacon blocks failed: %s", error_msg)
raise RequestFailure(error_msg)
self.logger.debug("Waiting for recent beacon blocks response")
try:
resp_code, recent_beacon_blocks_response = await read_resp(
stream,
RecentBeaconBlocksResponse,
)
has_error = False
except (ReadMessageFailure, MplexStreamEOF, MplexStreamReset) as error:
has_error = True
if isinstance(error, ReadMessageFailure):
await stream.reset()
elif isinstance(error, MplexStreamEOF):
await stream.close()
finally:
if has_error:
self.logger.info("Request recent beacon blocks failed: fail to read the response")
raise RequestFailure("fail to read the response")
self.logger.debug(
"Received recent beacon blocks response %s, resp_code=%s",
recent_beacon_blocks_response,
resp_code,
)
if resp_code != ResponseCode.SUCCESS:
error_msg = (
"resp_code != ResponseCode.SUCCESS, "
f"resp_code={resp_code}, error_msg={recent_beacon_blocks_response}"
)
self.logger.info("Request recent beacon blocks failed: %s", error_msg)
await stream.reset()
raise RequestFailure(error_msg)
await stream.close()
recent_beacon_blocks_response = cast(
RecentBeaconBlocksResponse,
recent_beacon_blocks_response,
)
return recent_beacon_blocks_response.blocks
class Node(BaseService):
_is_started: bool = False
key_pair: KeyPair
listen_ip: str
listen_port: int
host: BasicHost
pubsub: Pubsub
bootstrap_nodes: Tuple[Multiaddr, ...]
preferred_nodes: Tuple[Multiaddr, ...]
chain: BaseBeaconChain
subnets: Set[SubnetId]
_event_bus: EndpointAPI
handshaked_peers: PeerPool = None
def __init__(self,
key_pair: KeyPair,
listen_ip: str,
listen_port: int,
chain: BaseBeaconChain,
event_bus: EndpointAPI,
security_protocol_ops: Dict[TProtocol,
BaseSecureTransport] = None,
muxer_protocol_ops: Dict[TProtocol, IMuxedConn] = None,
gossipsub_params: Optional[GossipsubParams] = None,
cancel_token: CancelToken = None,
bootstrap_nodes: Tuple[Multiaddr, ...] = (),
preferred_nodes: Tuple[Multiaddr, ...] = (),
subnets: Optional[Set[SubnetId]] = None) -> None:
super().__init__(cancel_token)
self.listen_ip = listen_ip
self.listen_port = listen_port
self.key_pair = key_pair
self.bootstrap_nodes = bootstrap_nodes
self.preferred_nodes = preferred_nodes
self.subnets = subnets if subnets is not None else set()
# TODO: Add key and peer_id to the peerstore
if security_protocol_ops is None:
security_protocol_ops = {SecIOID: SecIOTransport(key_pair)}
if muxer_protocol_ops is None:
muxer_protocol_ops = {MPLEX_PROTOCOL_ID: Mplex}
network: INetwork = initialize_default_swarm(
key_pair=key_pair,
transport_opt=[self.listen_maddr],
muxer_opt=muxer_protocol_ops,
sec_opt=security_protocol_ops,
peerstore_opt=None, # let the function initialize it
)
self.host = BasicHost(network=network)
if gossipsub_params is None:
gossipsub_params = GossipsubParams()
gossipsub_router = GossipSub(
protocols=[GOSSIPSUB_PROTOCOL_ID],
degree=gossipsub_params.DEGREE,
degree_low=gossipsub_params.DEGREE_LOW,
degree_high=gossipsub_params.DEGREE_HIGH,
time_to_live=gossipsub_params.FANOUT_TTL,
gossip_window=gossipsub_params.GOSSIP_WINDOW,
gossip_history=gossipsub_params.GOSSIP_HISTORY,
heartbeat_interval=gossipsub_params.HEARTBEAT_INTERVAL,
)
self.pubsub = Pubsub(
host=self.host,
router=gossipsub_router,
my_id=self.peer_id,
)
self.chain = chain
self._event_bus = event_bus
self.handshaked_peers = PeerPool()
self.run_task(self.start())
@property
def is_started(self) -> bool:
return self._is_started
async def _run(self) -> None:
self.logger.info("libp2p node %s is up", self.listen_maddr)
self.run_daemon_task(self.update_status())
# Metrics and HTTP APIs
self.run_daemon_task(self.handle_libp2p_peers_requests())
self.run_daemon_task(self.handle_libp2p_peer_id_requests())
await self.cancellation()
async def start(self) -> None:
# host
self._register_rpc_handlers()
# TODO: Register notifees
is_listening = await self.host.get_network().listen(self.listen_maddr)
if not is_listening:
self.logger.error("Fail to listen on maddr: %s", self.listen_maddr)
raise NodeStartError(
f"Fail to listen on maddr: {self.listen_maddr}")
self.logger.warning("Node listening: %s",
self.listen_maddr_with_peer_id)
await self.connect_preferred_nodes()
# TODO: Connect bootstrap nodes?
# Pubsub
# Global channel
await self.pubsub.subscribe(PUBSUB_TOPIC_BEACON_BLOCK)
await self.pubsub.subscribe(PUBSUB_TOPIC_BEACON_ATTESTATION)
await self.pubsub.subscribe(PUBSUB_TOPIC_BEACON_AGGREGATE_AND_PROOF)
# Attestation subnets
for subnet_id in self.subnets:
topic = PUBSUB_TOPIC_COMMITTEE_BEACON_ATTESTATION.substitute(
subnet_id=str(subnet_id))
await self.pubsub.subscribe(topic)
self._setup_topic_validators()
self._is_started = True
def _setup_topic_validators(self) -> None:
# Global channel
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_BEACON_BLOCK,
get_beacon_block_validator(self.chain),
False,
)
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_BEACON_ATTESTATION,
get_beacon_attestation_validator(self.chain),
False,
)
# Attestation subnets
for subnet_id in self.subnets:
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_COMMITTEE_BEACON_ATTESTATION.substitute(
subnet_id=str(subnet_id)),
get_committee_index_beacon_attestation_validator(
self.chain, subnet_id),
False,
)
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_BEACON_AGGREGATE_AND_PROOF,
get_beacon_aggregate_and_proof_validator(self.chain),
False,
)
async def dial_peer_maddr(self, maddr: Multiaddr, peer_id: ID) -> None:
"""
Dial the peer with given multi-address
"""
self.logger.debug("Dialing peer_id: %s, maddr: %s", peer_id, maddr)
try:
await self.host.connect(PeerInfo(
peer_id=peer_id,
addrs=[maddr],
))
except SwarmException as e:
self.logger.debug("Fail to dial peer_id: %s, maddr: %s, error: %s",
peer_id, maddr, e)
raise DialPeerError from e
try:
# TODO: set a time limit on completing handshake
await self.request_status(peer_id)
except HandshakeFailure as e:
self.logger.debug("Fail to handshake with peer_id: %s, error: %s",
peer_id, e)
raise DialPeerError from e
self.logger.debug("Successfully connect to peer_id %s maddr %s",
peer_id, maddr)
async def dial_peer_maddr_with_retries(self, maddr: Multiaddr) -> None:
"""
Dial the peer with given multi-address repeatedly for `DIAL_RETRY_COUNT` times
"""
try:
p2p_id = maddr.value_for_protocol(protocols.P_P2P)
except (BinaryParseError, ProtocolLookupError) as error:
self.logger.debug("Invalid maddr: %s, error: %s", maddr, error)
raise DialPeerError from error
peer_id = ID.from_base58(p2p_id)
for i in range(DIAL_RETRY_COUNT):
try:
# exponential backoff...
await asyncio.sleep(2**i + random.random())
await self.dial_peer_maddr(maddr, peer_id)
return
except DialPeerError:
self.logger.debug(
"Could not dial peer: %s, maddr: %s retrying attempt %d of %d...",
peer_id,
maddr,
i,
DIAL_RETRY_COUNT,
)
continue
raise DialPeerError
async def connect_preferred_nodes(self) -> None:
results = await asyncio.gather(
*(self.dial_peer_maddr_with_retries(node_maddr)
for node_maddr in self.preferred_nodes),
return_exceptions=True,
)
for result, node_maddr in zip(results, self.preferred_nodes):
if isinstance(result, Exception):
logger.warning("Could not connect to preferred node at %s",
node_maddr)
async def disconnect_peer(self, peer_id: ID) -> None:
if peer_id in self.handshaked_peers:
self.logger.debug("Disconnect from %s", peer_id)
self.handshaked_peers.remove(peer_id)
await self.host.disconnect(peer_id)
else:
self.logger.debug("Already disconnected from %s", peer_id)
async def broadcast_beacon_block(self,
block: BaseSignedBeaconBlock) -> None:
await self._broadcast_data(PUBSUB_TOPIC_BEACON_BLOCK,
ssz.encode(block))
async def broadcast_attestation(self, attestation: Attestation) -> None:
await self._broadcast_data(PUBSUB_TOPIC_BEACON_ATTESTATION,
ssz.encode(attestation))
async def broadcast_attestation_to_subnet(self, attestation: Attestation,
subnet_id: SubnetId) -> None:
await self._broadcast_data(
PUBSUB_TOPIC_COMMITTEE_BEACON_ATTESTATION.substitute(
subnet_id=str(subnet_id)), ssz.encode(attestation))
async def broadcast_beacon_aggregate_and_proof(
self, aggregate_and_proof: AggregateAndProof) -> None:
await self._broadcast_data(
PUBSUB_TOPIC_BEACON_AGGREGATE_AND_PROOF,
ssz.encode(aggregate_and_proof),
)
async def _broadcast_data(self, topic: str, data: bytes) -> None:
await self.pubsub.publish(topic, data)
@property
def peer_id(self) -> ID:
return self.host.get_id()
@property
def listen_maddr(self) -> Multiaddr:
return make_tcp_ip_maddr(self.listen_ip, self.listen_port)
@property
def listen_maddr_with_peer_id(self) -> Multiaddr:
return self.listen_maddr.encapsulate(
Multiaddr(f"/p2p/{self.peer_id.to_base58()}"))
@property
def peer_store(self) -> PeerStore:
return self.host.get_network().peerstore
async def close(self) -> None:
# FIXME: Add `tear_down` to `Swarm` in the upstream
network = self.host.get_network()
for listener in network.listeners.values():
listener.server.close()
await listener.server.wait_closed()
# TODO: Add `close` in `Pubsub`
def _register_rpc_handlers(self) -> None:
self.host.set_stream_handler(REQ_RESP_STATUS_SSZ, self._handle_status)
self.host.set_stream_handler(REQ_RESP_GOODBYE_SSZ,
self._handle_goodbye)
self.host.set_stream_handler(
REQ_RESP_BEACON_BLOCKS_BY_RANGE_SSZ,
self._handle_beacon_blocks_by_range,
)
self.host.set_stream_handler(
REQ_RESP_BEACON_BLOCKS_BY_ROOT_SSZ,
self._handle_beacon_blocks_by_root,
)
#
# RPC Handlers
#
async def new_stream(self, peer_id: ID, protocol: TProtocol) -> INetStream:
return await self.host.new_stream(peer_id, [protocol])
@asynccontextmanager
async def new_handshake_interaction(
self, stream: INetStream) -> AsyncIterator[Interaction]:
try:
async with Interaction(stream) as interaction:
peer_id = interaction.peer_id
yield interaction
except MessageIOFailure as error:
await self.disconnect_peer(peer_id)
raise HandshakeFailure() from error
except PeerRespondedAnError as error:
await stream.reset()
await self.disconnect_peer(peer_id)
raise HandshakeFailure() from error
except IrrelevantNetwork as error:
await stream.reset()
asyncio.ensure_future(
self.say_goodbye(peer_id,
GoodbyeReasonCode.IRRELEVANT_NETWORK))
raise HandshakeFailure from error
@asynccontextmanager
async def post_handshake_handler_interaction(
self, stream: INetStream) -> AsyncIterator[Interaction]:
try:
async with Interaction(stream) as interaction:
yield interaction
except WriteMessageFailure as error:
self.logger.debug("WriteMessageFailure %s", error)
return
except ReadMessageFailure as error:
self.logger.debug("ReadMessageFailure %s", error)
return
except UnhandshakedPeer:
await stream.reset()
return
@asynccontextmanager
async def my_request_interaction(
self, stream: INetStream) -> AsyncIterator[Interaction]:
try:
async with Interaction(stream) as interaction:
yield interaction
except (MessageIOFailure, UnhandshakedPeer,
PeerRespondedAnError) as error:
raise RequestFailure(str(error)) from error
# TODO: Handle the reputation of peers. Deduct their scores and even disconnect when they
# behave.
# TODO: Register notifee to the `Network` to
# - Record peers' joining time.
# - Disconnect peers when they fail to join in a certain amount of time.
def _add_peer_from_status(self, peer_id: ID, status: Status) -> None:
peer = Peer.from_status(self, peer_id, status)
self.handshaked_peers.add(peer)
self.logger.debug(
"Handshake from %s is finished. Added to the `handshake_peers`",
peer_id,
)
async def _handle_status(self, stream: INetStream) -> None:
# TODO: Find out when we should respond the `ResponseCode`
# other than `ResponseCode.SUCCESS`.
async with self.new_handshake_interaction(stream) as interaction:
peer_id = interaction.peer_id
peer_status = await interaction.read_request(Status)
self.logger.info("Received Status from %s %s", str(peer_id),
peer_status)
await validate_peer_status(self.chain, peer_status)
my_status = get_my_status(self.chain)
await interaction.write_response(my_status)
self._add_peer_from_status(peer_id, peer_status)
if peer_is_ahead(self.chain, peer_status):
logger.debug(
"Peer's chain is ahead of us, start syncing with the peer(%s)",
str(peer_id),
)
await self._event_bus.broadcast(SyncRequest())
async def request_status(self, peer_id: ID) -> None:
self.logger.info("Initiate handshake with %s", str(peer_id))
try:
stream = await self.new_stream(peer_id, REQ_RESP_STATUS_SSZ)
except StreamFailure as error:
self.logger.debug("Fail to open stream to %s", str(peer_id))
raise HandshakeFailure from error
async with self.new_handshake_interaction(stream) as interaction:
my_status = get_my_status(self.chain)
await interaction.write_request(my_status)
peer_status = await interaction.read_response(Status)
await validate_peer_status(self.chain, peer_status)
self._add_peer_from_status(peer_id, peer_status)
if peer_is_ahead(self.chain, peer_status):
logger.debug(
"Peer's chain is ahead of us, start syncing with the peer(%s)",
str(peer_id),
)
await self._event_bus.broadcast(SyncRequest())
async def _handle_goodbye(self, stream: INetStream) -> None:
async with Interaction(stream) as interaction:
peer_id = interaction.peer_id
try:
await interaction.read_request(Goodbye)
except ReadMessageFailure:
pass
await self.disconnect_peer(peer_id)
async def say_goodbye(self, peer_id: ID,
reason: GoodbyeReasonCode) -> None:
try:
stream = await self.new_stream(peer_id, REQ_RESP_GOODBYE_SSZ)
except StreamFailure:
self.logger.debug("Fail to open stream to %s", str(peer_id))
else:
async with Interaction(stream) as interaction:
goodbye = Goodbye.create(reason)
try:
await interaction.write_request(goodbye)
except WriteMessageFailure:
pass
finally:
await self.disconnect_peer(peer_id)
def _check_peer_handshaked(self, peer_id: ID) -> None:
if peer_id not in self.handshaked_peers:
raise UnhandshakedPeer(peer_id)
async def _handle_beacon_blocks_by_range(self, stream: INetStream) -> None:
# TODO: Should it be a successful response if peer is requesting
# blocks on a fork we don't have data for?
async with self.post_handshake_handler_interaction(
stream) as interaction:
peer_id = interaction.peer_id
self._check_peer_handshaked(peer_id)
request = await interaction.read_request(BeaconBlocksByRangeRequest
)
try:
blocks = get_requested_beacon_blocks(self.chain, request)
except InvalidRequest as error:
error_message = str(error)[:128]
await interaction.write_error_response(
error_message, ResponseCode.INVALID_REQUEST)
else:
await interaction.write_chunk_response(blocks)
async def request_beacon_blocks_by_range(
self,
peer_id: ID,
head_block_root: Root,
start_slot: Slot,
count: int,
step: int,
) -> Tuple[BaseSignedBeaconBlock, ...]:
try:
stream = await self.new_stream(
peer_id, REQ_RESP_BEACON_BLOCKS_BY_RANGE_SSZ)
except StreamFailure as error:
self.logger.debug("Fail to open stream to %s", str(peer_id))
raise RequestFailure(str(error)) from error
async with self.my_request_interaction(stream) as interaction:
self._check_peer_handshaked(peer_id)
request = BeaconBlocksByRangeRequest.create(
head_block_root=head_block_root,
start_slot=start_slot,
count=count,
step=step,
)
await interaction.write_request(request)
blocks = tuple([
block async for block in interaction.read_chunk_response(
SignedBeaconBlock, count)
])
return blocks
async def _handle_beacon_blocks_by_root(self, stream: INetStream) -> None:
async with self.post_handshake_handler_interaction(
stream) as interaction:
peer_id = interaction.peer_id
self._check_peer_handshaked(peer_id)
request = await interaction.read_request(BeaconBlocksByRootRequest)
blocks = get_beacon_blocks_by_root(self.chain, request)
await interaction.write_chunk_response(blocks)
async def request_beacon_blocks_by_root(
self, peer_id: ID,
block_roots: Sequence[Root]) -> Tuple[BaseSignedBeaconBlock, ...]:
try:
stream = await self.new_stream(peer_id,
REQ_RESP_BEACON_BLOCKS_BY_ROOT_SSZ)
except StreamFailure as error:
self.logger.debug("Fail to open stream to %s", str(peer_id))
raise RequestFailure(str(error)) from error
async with self.my_request_interaction(stream) as interaction:
self._check_peer_handshaked(peer_id)
request = BeaconBlocksByRootRequest.create(block_roots=block_roots)
await interaction.write_request(request)
blocks = tuple([
block async for block in interaction.read_chunk_response(
SignedBeaconBlock, len(block_roots))
])
return blocks
async def update_status(self) -> None:
while True:
for peer_id in self.handshaked_peers.peer_ids:
asyncio.ensure_future(self.request_status(peer_id))
await asyncio.sleep(NEXT_UPDATE_INTERVAL)
#
# Metrics and APIs
#
async def handle_libp2p_peers_requests(self) -> None:
async for req in self.wait_iter(
self._event_bus.stream(Libp2pPeersRequest)):
peers = tuple(self.handshaked_peers.peer_ids)
await self._event_bus.broadcast(
Libp2pPeersResponse(peers),
req.broadcast_config(),
)
async def handle_libp2p_peer_id_requests(self) -> None:
async for req in self.wait_iter(
self._event_bus.stream(Libp2pPeerIDRequest)):
await self._event_bus.broadcast(
Libp2pPeerIDResponse(self.peer_id),
req.broadcast_config(),
)
class Node(BaseService):
_is_started: bool = False
key_pair: KeyPair
listen_ip: str
listen_port: int
host: BasicHost
pubsub: Pubsub
bootstrap_nodes: Tuple[Multiaddr, ...]
preferred_nodes: Tuple[Multiaddr, ...]
chain: BaseBeaconChain
handshaked_peers: PeerPool = None
def __init__(
self,
key_pair: KeyPair,
listen_ip: str,
listen_port: int,
chain: BaseBeaconChain,
security_protocol_ops: Dict[TProtocol, BaseSecureTransport] = None,
muxer_protocol_ops: Dict[TProtocol, IMuxedConn] = None,
gossipsub_params: Optional[GossipsubParams] = None,
cancel_token: CancelToken = None,
bootstrap_nodes: Tuple[Multiaddr, ...] = (),
preferred_nodes: Tuple[Multiaddr, ...] = ()) -> None:
super().__init__(cancel_token)
self.listen_ip = listen_ip
self.listen_port = listen_port
self.key_pair = key_pair
self.bootstrap_nodes = bootstrap_nodes
self.preferred_nodes = preferred_nodes
# TODO: Add key and peer_id to the peerstore
if security_protocol_ops is None:
security_protocol_ops = {
SecIOID: SecIOTransport(key_pair)
}
if muxer_protocol_ops is None:
muxer_protocol_ops = {MPLEX_PROTOCOL_ID: Mplex}
network: INetwork = initialize_default_swarm(
key_pair=key_pair,
transport_opt=[self.listen_maddr],
muxer_opt=muxer_protocol_ops,
sec_opt=security_protocol_ops,
peerstore_opt=None, # let the function initialize it
disc_opt=None, # no routing required here
)
self.host = BasicHost(network=network, router=None)
if gossipsub_params is None:
gossipsub_params = GossipsubParams()
gossipsub_router = GossipSub(
protocols=[GOSSIPSUB_PROTOCOL_ID],
degree=gossipsub_params.DEGREE,
degree_low=gossipsub_params.DEGREE_LOW,
degree_high=gossipsub_params.DEGREE_HIGH,
time_to_live=gossipsub_params.FANOUT_TTL,
gossip_window=gossipsub_params.GOSSIP_WINDOW,
gossip_history=gossipsub_params.GOSSIP_HISTORY,
heartbeat_interval=gossipsub_params.HEARTBEAT_INTERVAL,
)
self.pubsub = Pubsub(
host=self.host,
router=gossipsub_router,
my_id=self.peer_id,
)
self.chain = chain
self.handshaked_peers = PeerPool()
self.run_task(self.start())
@property
def is_started(self) -> bool:
return self._is_started
async def _run(self) -> None:
self.logger.info("libp2p node %s is up", self.listen_maddr)
await self.cancellation()
async def start(self) -> None:
# host
self._register_rpc_handlers()
# TODO: Register notifees
await self.host.get_network().listen(self.listen_maddr)
await self.connect_preferred_nodes()
# TODO: Connect bootstrap nodes?
# pubsub
await self.pubsub.subscribe(PUBSUB_TOPIC_BEACON_BLOCK)
await self.pubsub.subscribe(PUBSUB_TOPIC_BEACON_ATTESTATION)
self._setup_topic_validators()
self._is_started = True
def _setup_topic_validators(self) -> None:
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_BEACON_BLOCK,
get_beacon_block_validator(self.chain),
False,
)
self.pubsub.set_topic_validator(
PUBSUB_TOPIC_BEACON_ATTESTATION,
get_beacon_attestation_validator(self.chain),
False,
)
async def dial_peer(self, ip: str, port: int, peer_id: ID) -> None:
"""
Dial the peer ``peer_id`` through the IPv4 protocol
"""
await self.host.connect(
PeerInfo(
peer_id=peer_id,
addrs=[make_tcp_ip_maddr(ip, port)],
)
)
try:
# TODO: set a time limit on completing handshake
await self.request_status(peer_id)
except HandshakeFailure as e:
self.logger.info("HandshakeFailure: %s", str(e))
# TODO: handle it
async def dial_peer_with_retries(self, ip: str, port: int, peer_id: ID) -> None:
"""
Dial the peer ``peer_id`` through the IPv4 protocol
"""
for i in range(DIAL_RETRY_COUNT):
try:
# exponential backoff...
await asyncio.sleep(2**i + random.random())
await self.dial_peer(ip, port, peer_id)
return
except ConnectionRefusedError:
logger.debug(
"could not connect to peer %s at %s:%d;"
" retrying attempt %d of %d...",
peer_id,
ip,
port,
i,
DIAL_RETRY_COUNT,
)
continue
raise ConnectionRefusedError
async def dial_peer_maddr(self, maddr: Multiaddr) -> None:
"""
Parse `maddr`, get the ip:port and PeerID, and call `dial_peer` with the parameters.
"""
try:
ip = maddr.value_for_protocol(protocols.P_IP4)
port = maddr.value_for_protocol(protocols.P_TCP)
peer_id = ID.from_base58(maddr.value_for_protocol(protocols.P_P2P))
await self.dial_peer_with_retries(ip=ip, port=port, peer_id=peer_id)
except Exception:
traceback.print_exc()
raise
async def connect_preferred_nodes(self) -> None:
results = await asyncio.gather(
*(self.dial_peer_maddr(node_maddr)
for node_maddr in self.preferred_nodes),
return_exceptions=True,
)
for result in results:
if isinstance(result, Exception):
logger.warning("could not connect to %s", result)
async def disconnect_peer(self, peer_id: ID) -> None:
if peer_id in self.handshaked_peers:
self.logger.debug("Disconnect from %s", peer_id)
self.handshaked_peers.remove(peer_id)
await self.host.disconnect(peer_id)
else:
self.logger.debug("Already disconnected from %s", peer_id)
async def broadcast_beacon_block(self, block: BaseBeaconBlock) -> None:
await self._broadcast_data(PUBSUB_TOPIC_BEACON_BLOCK, ssz.encode(block))
async def broadcast_attestation(self, attestation: Attestation) -> None:
await self._broadcast_data(PUBSUB_TOPIC_BEACON_ATTESTATION, ssz.encode(attestation))
async def _broadcast_data(self, topic: str, data: bytes) -> None:
await self.pubsub.publish(topic, data)
@property
def peer_id(self) -> ID:
return self.host.get_id()
@property
def listen_maddr(self) -> Multiaddr:
return make_tcp_ip_maddr(self.listen_ip, self.listen_port)
@property
def listen_maddr_with_peer_id(self) -> Multiaddr:
return self.listen_maddr.encapsulate(Multiaddr(f"/p2p/{self.peer_id.to_base58()}"))
@property
def peer_store(self) -> PeerStore:
return self.host.get_network().peerstore
async def close(self) -> None:
# FIXME: Add `tear_down` to `Swarm` in the upstream
network = self.host.get_network()
for listener in network.listeners.values():
listener.server.close()
await listener.server.wait_closed()
# TODO: Add `close` in `Pubsub`
def _register_rpc_handlers(self) -> None:
self.host.set_stream_handler(REQ_RESP_STATUS_SSZ, self._handle_status)
self.host.set_stream_handler(REQ_RESP_GOODBYE_SSZ, self._handle_goodbye)
self.host.set_stream_handler(
REQ_RESP_BEACON_BLOCKS_BY_RANGE_SSZ,
self._handle_beacon_blocks_by_range,
)
self.host.set_stream_handler(
REQ_RESP_BEACON_BLOCKS_BY_ROOT_SSZ,
self._handle_beacon_blocks_by_root,
)
#
# RPC Handlers
#
async def new_stream(self, peer_id: ID, protocol: TProtocol) -> INetStream:
return await self.host.new_stream(peer_id, [protocol])
@asynccontextmanager
async def new_handshake_interaction(self, stream: INetStream) -> AsyncIterator[Interaction]:
try:
async with Interaction(stream) as interaction:
peer_id = interaction.peer_id
yield interaction
except MessageIOFailure as error:
await self.disconnect_peer(peer_id)
raise HandshakeFailure() from error
except PeerRespondedAnError as error:
await stream.reset()
await self.disconnect_peer(peer_id)
raise HandshakeFailure() from error
except IrrelevantNetwork as error:
await stream.reset()
asyncio.ensure_future(
self.say_goodbye(peer_id, GoodbyeReasonCode.IRRELEVANT_NETWORK)
)
raise HandshakeFailure from error
@asynccontextmanager
async def post_handshake_handler_interaction(
self,
stream: INetStream
) -> AsyncIterator[Interaction]:
try:
async with Interaction(stream) as interaction:
yield interaction
except WriteMessageFailure as error:
self.logger.debug("WriteMessageFailure %s", error)
return
except ReadMessageFailure as error:
self.logger.debug("ReadMessageFailure %s", error)
return
except UnhandshakedPeer:
await stream.reset()
return
@asynccontextmanager
async def my_request_interaction(self, stream: INetStream) -> AsyncIterator[Interaction]:
try:
async with Interaction(stream) as interaction:
yield interaction
except (MessageIOFailure, UnhandshakedPeer, PeerRespondedAnError) as error:
raise RequestFailure(str(error)) from error
# TODO: Handle the reputation of peers. Deduct their scores and even disconnect when they
# behave.
# TODO: Register notifee to the `Network` to
# - Record peers' joining time.
# - Disconnect peers when they fail to join in a certain amount of time.
def _add_peer_from_status(self, peer_id: ID, status: Status) -> None:
peer = Peer.from_status(self, peer_id, status)
self.handshaked_peers.add(peer)
self.logger.debug(
"Handshake from %s is finished. Added to the `handshake_peers`",
peer_id,
)
async def _handle_status(self, stream: INetStream) -> None:
# TODO: Find out when we should respond the `ResponseCode`
# other than `ResponseCode.SUCCESS`.
async with self.new_handshake_interaction(stream) as interaction:
peer_id = interaction.peer_id
peer_status = await interaction.read_request(Status)
self.logger.info("Received Status from %s %s", str(peer_id), peer_status)
await validate_peer_status(self.chain, peer_status)
my_status = get_my_status(self.chain)
await interaction.write_response(my_status)
self._add_peer_from_status(peer_id, peer_status)
# Check if we are behind the peer
compare_chain_tip_and_finalized_epoch(self.chain, peer_status)
async def request_status(self, peer_id: ID) -> None:
self.logger.info("Initiate handshake with %s", str(peer_id))
stream = await self.new_stream(peer_id, REQ_RESP_STATUS_SSZ)
async with self.new_handshake_interaction(stream) as interaction:
my_status = get_my_status(self.chain)
await interaction.write_request(my_status)
peer_status = await interaction.read_response(Status)
await validate_peer_status(self.chain, peer_status)
self._add_peer_from_status(peer_id, peer_status)
# Check if we are behind the peer
compare_chain_tip_and_finalized_epoch(self.chain, peer_status)
async def _handle_goodbye(self, stream: INetStream) -> None:
async with Interaction(stream) as interaction:
peer_id = interaction.peer_id
try:
await interaction.read_request(Goodbye)
except ReadMessageFailure:
pass
await self.disconnect_peer(peer_id)
async def say_goodbye(self, peer_id: ID, reason: GoodbyeReasonCode) -> None:
stream = await self.new_stream(peer_id, REQ_RESP_GOODBYE_SSZ)
async with Interaction(stream) as interaction:
goodbye = Goodbye(reason)
try:
await interaction.write_request(goodbye)
except WriteMessageFailure:
pass
await self.disconnect_peer(peer_id)
def _check_peer_handshaked(self, peer_id: ID) -> None:
if peer_id not in self.handshaked_peers:
raise UnhandshakedPeer(peer_id)
async def _handle_beacon_blocks_by_range(self, stream: INetStream) -> None:
# TODO: Should it be a successful response if peer is requesting
# blocks on a fork we don't have data for?
async with self.post_handshake_handler_interaction(stream) as interaction:
peer_id = interaction.peer_id
self._check_peer_handshaked(peer_id)
request = await interaction.read_request(BeaconBlocksByRangeRequest)
try:
blocks = get_requested_beacon_blocks(self.chain, request)
except InvalidRequest as error:
error_message = str(error)[:128]
await interaction.write_error_response(error_message, ResponseCode.INVALID_REQUEST)
else:
await interaction.write_chunk_response(blocks)
async def request_beacon_blocks_by_range(
self,
peer_id: ID,
head_block_root: SigningRoot,
start_slot: Slot,
count: int,
step: int,
) -> Tuple[BaseBeaconBlock, ...]:
stream = await self.new_stream(peer_id, REQ_RESP_BEACON_BLOCKS_BY_RANGE_SSZ)
async with self.my_request_interaction(stream) as interaction:
self._check_peer_handshaked(peer_id)
request = BeaconBlocksByRangeRequest(
head_block_root=head_block_root,
start_slot=start_slot,
count=count,
step=step,
)
await interaction.write_request(request)
blocks = tuple([
block async for block in
interaction.read_chunk_response(BeaconBlock, count)
])
return blocks
async def _handle_beacon_blocks_by_root(self, stream: INetStream) -> None:
async with self.post_handshake_handler_interaction(stream) as interaction:
peer_id = interaction.peer_id
self._check_peer_handshaked(peer_id)
request = await interaction.read_request(BeaconBlocksByRootRequest)
blocks = get_beacon_blocks_by_root(self.chain, request)
await interaction.write_chunk_response(blocks)
async def request_beacon_blocks_by_root(
self,
peer_id: ID,
block_roots: Sequence[SigningRoot]) -> Tuple[BaseBeaconBlock, ...]:
stream = await self.new_stream(peer_id, REQ_RESP_BEACON_BLOCKS_BY_ROOT_SSZ)
async with self.my_request_interaction(stream) as interaction:
self._check_peer_handshaked(peer_id)
request = BeaconBlocksByRootRequest(block_roots=block_roots)
await interaction.write_request(request)
blocks = tuple([
block async for block in
interaction.read_chunk_response(BeaconBlock, len(block_roots))
])
return blocks
class Gossiper:
GOSSIP_MAX_SIZE: int = 2**20
MAXIMUM_GOSSIP_CLOCK_DISPARITY = 0.5 # seconds
# `D` (topic stable mesh target count)
DEGREE: int = 6
# `D_low` (topic stable mesh low watermark)
DEGREE_LOW: int = 4
# `D_high` (topic stable mesh high watermark)
DEGREE_HIGH: int = 12
# `D_lazy` (gossip target)
DEGREE_LAZY: int = 6
# `fanout_ttl` (ttl for fanout maps for topics we are not subscribed to
# but have published to seconds).
FANOUT_TTL: int = 60
# `gossip_advertise` (number of windows to gossip about).
GOSSIP_WINDOW: int = 3
# `gossip_history` (number of heartbeat intervals to retain message IDs).
GOSSIP_HISTORY: int = 5
# `heartbeat_interval` (frequency of heartbeat, seconds).
HEARTBEAT_INTERVAL: int = 1 # seconds
ATTESTATION_SUBNET_COUNT = 64
ATTESTATION_PROPAGATION_SLOT_RANGE = 32
def __init__(self, fork_digest_provider: ForkDigestProvider,
host: IHost) -> None:
self._fork_digest_provider = fork_digest_provider
self._host = host
gossipsub_router = GossipSub(
protocols=[GOSSIPSUB_PROTOCOL_ID],
degree=self.DEGREE,
degree_low=self.DEGREE_LOW,
degree_high=self.DEGREE_HIGH,
time_to_live=self.FANOUT_TTL,
gossip_window=self.GOSSIP_WINDOW,
gossip_history=self.GOSSIP_HISTORY,
heartbeat_interval=self.HEARTBEAT_INTERVAL,
)
self.gossipsub = gossipsub_router
self.pubsub = Pubsub(
host=self._host,
router=gossipsub_router,
msg_id_constructor=get_content_addressed_msg_id,
)
async def _subscribe_to_gossip_topic(
self, topic: str, validator: GossipValidator) -> ISubscriptionAPI:
self.pubsub.set_topic_validator(topic, validator, False)
return await self.pubsub.subscribe(topic)
def _gossip_topic_id_for(self, topic: PubSubTopic) -> str:
return f"/eth2/{self._fork_digest_provider().hex()}/{topic.value}/ssz_snappy"
async def subscribe_gossip_channels(self) -> None:
# TODO handle concurrently
self._block_gossip = await self._subscribe_to_gossip_topic(
self._gossip_topic_id_for(PubSubTopic.beacon_block),
validator=_validate_beacon_block_gossip(self),
)
self._attestation_gossip = await self._subscribe_to_gossip_topic(
self._gossip_topic_id_for(PubSubTopic.attestation),
validator=_validate_attestation_gossip(self),
)
async def unsubscribe_gossip_channels(self) -> None:
# TODO handle concurrently
await self.pubsub.unsubscribe(
self._gossip_topic_id_for(PubSubTopic.beacon_block))
await self.pubsub.unsubscribe(
self._gossip_topic_id_for(PubSubTopic.attestation))
async def stream_block_gossip(self) -> AsyncIterable[SignedBeaconBlock]:
async with self._block_gossip:
async for block_message in self._block_gossip:
if block_message.from_id == self.pubsub.my_id:
# FIXME: this check should happen inside `py-libp2p`
continue
# TODO: validate block further at the p2p layer?
block_data = block_message.data
yield _deserialize_gossip(block_data, SignedBeaconBlock)
async def broadcast_block(self, block: SignedBeaconBlock) -> None:
gossip = _serialize_gossip(block)
await self.pubsub.publish(
self._gossip_topic_id_for(PubSubTopic.beacon_block), gossip)
