590 lines
20 KiB
Python
590 lines
20 KiB
Python
import asyncio
|
|
import logging
|
|
import time
|
|
from typing import (
|
|
TYPE_CHECKING,
|
|
Awaitable,
|
|
Callable,
|
|
Dict,
|
|
List,
|
|
NamedTuple,
|
|
Tuple,
|
|
Union,
|
|
cast,
|
|
)
|
|
|
|
import base58
|
|
from lru import LRU
|
|
|
|
from libp2p.crypto.keys import PrivateKey
|
|
from libp2p.exceptions import ParseError, ValidationError
|
|
from libp2p.host.host_interface import IHost
|
|
from libp2p.io.exceptions import IncompleteReadError
|
|
from libp2p.network.exceptions import SwarmException
|
|
from libp2p.network.stream.exceptions import StreamClosed, StreamEOF, StreamReset
|
|
from libp2p.network.stream.net_stream_interface import INetStream
|
|
from libp2p.peer.id import ID
|
|
from libp2p.typing import TProtocol
|
|
from libp2p.utils import encode_varint_prefixed, read_varint_prefixed_bytes
|
|
|
|
from .pb import rpc_pb2
|
|
from .pubsub_notifee import PubsubNotifee
|
|
from .validators import PUBSUB_SIGNING_PREFIX, signature_validator
|
|
|
|
if TYPE_CHECKING:
|
|
from .pubsub_router_interface import IPubsubRouter # noqa: F401
|
|
from typing import Any # noqa: F401
|
|
|
|
|
|
logger = logging.getLogger("libp2p.pubsub")
|
|
|
|
|
|
def get_msg_id(msg: rpc_pb2.Message) -> Tuple[bytes, bytes]:
|
|
# NOTE: `string(from, seqno)` in Go
|
|
return (msg.seqno, msg.from_id)
|
|
|
|
|
|
SyncValidatorFn = Callable[[ID, rpc_pb2.Message], bool]
|
|
AsyncValidatorFn = Callable[[ID, rpc_pb2.Message], Awaitable[bool]]
|
|
ValidatorFn = Union[SyncValidatorFn, AsyncValidatorFn]
|
|
|
|
|
|
class TopicValidator(NamedTuple):
|
|
validator: ValidatorFn
|
|
is_async: bool
|
|
|
|
|
|
class Pubsub:
|
|
|
|
host: IHost
|
|
my_id: ID
|
|
|
|
router: "IPubsubRouter"
|
|
|
|
peer_queue: "asyncio.Queue[ID]"
|
|
dead_peer_queue: "asyncio.Queue[ID]"
|
|
|
|
protocols: List[TProtocol]
|
|
|
|
incoming_msgs_from_peers: "asyncio.Queue[rpc_pb2.Message]"
|
|
outgoing_messages: "asyncio.Queue[rpc_pb2.Message]"
|
|
|
|
seen_messages: LRU
|
|
|
|
my_topics: Dict[str, "asyncio.Queue[rpc_pb2.Message]"]
|
|
|
|
peer_topics: Dict[str, List[ID]]
|
|
peers: Dict[ID, INetStream]
|
|
|
|
topic_validators: Dict[str, TopicValidator]
|
|
|
|
counter: int # uint64
|
|
|
|
_tasks: List["asyncio.Future[Any]"]
|
|
|
|
# Indicate if we should enforce signature verification
|
|
strict_signing: bool
|
|
sign_key: PrivateKey
|
|
|
|
def __init__(
|
|
self,
|
|
host: IHost,
|
|
router: "IPubsubRouter",
|
|
my_id: ID,
|
|
cache_size: int = None,
|
|
strict_signing: bool = True,
|
|
) -> None:
|
|
"""
|
|
Construct a new Pubsub object, which is responsible for handling all
|
|
Pubsub-related messages and relaying messages as appropriate to the
|
|
Pubsub router (which is responsible for choosing who to send messages
|
|
to).
|
|
|
|
Since the logic for choosing peers to send pubsub messages to is
|
|
in the router, the same Pubsub impl can back floodsub,
|
|
gossipsub, etc.
|
|
"""
|
|
self.host = host
|
|
self.router = router
|
|
self.my_id = my_id
|
|
|
|
# Attach this new Pubsub object to the router
|
|
self.router.attach(self)
|
|
|
|
# Register a notifee
|
|
self.peer_queue = asyncio.Queue()
|
|
self.dead_peer_queue = asyncio.Queue()
|
|
self.host.get_network().register_notifee(
|
|
PubsubNotifee(self.peer_queue, self.dead_peer_queue)
|
|
)
|
|
|
|
# Register stream handlers for each pubsub router protocol to handle
|
|
# the pubsub streams opened on those protocols
|
|
self.protocols = self.router.get_protocols()
|
|
for protocol in self.protocols:
|
|
self.host.set_stream_handler(protocol, self.stream_handler)
|
|
|
|
# Use asyncio queues for proper context switching
|
|
self.incoming_msgs_from_peers = asyncio.Queue()
|
|
self.outgoing_messages = asyncio.Queue()
|
|
|
|
# keeps track of seen messages as LRU cache
|
|
if cache_size is None:
|
|
self.cache_size = 128
|
|
else:
|
|
self.cache_size = cache_size
|
|
|
|
self.seen_messages = LRU(self.cache_size)
|
|
|
|
# Map of topics we are subscribed to blocking queues
|
|
# for when the given topic receives a message
|
|
self.my_topics = {}
|
|
|
|
# Map of topic to peers to keep track of what peers are subscribed to
|
|
self.peer_topics = {}
|
|
|
|
# Create peers map, which maps peer_id (as string) to stream (to a given peer)
|
|
self.peers = {}
|
|
|
|
# Map of topic to topic validator
|
|
self.topic_validators = {}
|
|
|
|
self.counter = time.time_ns()
|
|
|
|
self._tasks = []
|
|
# Call handle peer to keep waiting for updates to peer queue
|
|
self._tasks.append(asyncio.ensure_future(self.handle_peer_queue()))
|
|
self._tasks.append(asyncio.ensure_future(self.handle_dead_peer_queue()))
|
|
|
|
self.strict_signing = strict_signing
|
|
if strict_signing:
|
|
self.sign_key = self.host.get_private_key()
|
|
else:
|
|
self.sign_key = None
|
|
|
|
def get_hello_packet(self) -> rpc_pb2.RPC:
|
|
"""Generate subscription message with all topics we are subscribed to
|
|
only send hello packet if we have subscribed topics."""
|
|
packet = rpc_pb2.RPC()
|
|
for topic_id in self.my_topics:
|
|
packet.subscriptions.extend(
|
|
[rpc_pb2.RPC.SubOpts(subscribe=True, topicid=topic_id)]
|
|
)
|
|
return packet
|
|
|
|
async def continuously_read_stream(self, stream: INetStream) -> None:
|
|
"""
|
|
Read from input stream in an infinite loop. Process messages from other
|
|
nodes.
|
|
|
|
:param stream: stream to continously read from
|
|
"""
|
|
peer_id = stream.muxed_conn.peer_id
|
|
|
|
while True:
|
|
incoming: bytes = await read_varint_prefixed_bytes(stream)
|
|
rpc_incoming: rpc_pb2.RPC = rpc_pb2.RPC()
|
|
rpc_incoming.ParseFromString(incoming)
|
|
if rpc_incoming.publish:
|
|
# deal with RPC.publish
|
|
for msg in rpc_incoming.publish:
|
|
if not self._is_subscribed_to_msg(msg):
|
|
continue
|
|
logger.debug(
|
|
"received `publish` message %s from peer %s", msg, peer_id
|
|
)
|
|
self._tasks.append(
|
|
asyncio.ensure_future(
|
|
self.push_msg(msg_forwarder=peer_id, msg=msg)
|
|
)
|
|
)
|
|
|
|
if rpc_incoming.subscriptions:
|
|
# deal with RPC.subscriptions
|
|
# We don't need to relay the subscription to our
|
|
# peers because a given node only needs its peers
|
|
# to know that it is subscribed to the topic (doesn't
|
|
# need everyone to know)
|
|
for message in rpc_incoming.subscriptions:
|
|
logger.debug(
|
|
"received `subscriptions` message %s from peer %s",
|
|
message,
|
|
peer_id,
|
|
)
|
|
self.handle_subscription(peer_id, message)
|
|
|
|
# NOTE: Check if `rpc_incoming.control` is set through `HasField`.
|
|
# This is necessary because `control` is an optional field in pb2.
|
|
# Ref: https://developers.google.com/protocol-buffers/docs/reference/python-generated#singular-fields-proto2 # noqa: E501
|
|
if rpc_incoming.HasField("control"):
|
|
# Pass rpc to router so router could perform custom logic
|
|
logger.debug(
|
|
"received `control` message %s from peer %s",
|
|
rpc_incoming.control,
|
|
peer_id,
|
|
)
|
|
await self.router.handle_rpc(rpc_incoming, peer_id)
|
|
|
|
# Force context switch
|
|
await asyncio.sleep(0)
|
|
|
|
def set_topic_validator(
|
|
self, topic: str, validator: ValidatorFn, is_async_validator: bool
|
|
) -> None:
|
|
"""
|
|
Register a validator under the given topic. One topic can only have one
|
|
validtor.
|
|
|
|
:param topic: the topic to register validator under
|
|
:param validator: the validator used to validate messages published to the topic
|
|
:param is_async_validator: indicate if the validator is an asynchronous validator
|
|
"""
|
|
self.topic_validators[topic] = TopicValidator(validator, is_async_validator)
|
|
|
|
def remove_topic_validator(self, topic: str) -> None:
|
|
"""
|
|
Remove the validator from the given topic.
|
|
|
|
:param topic: the topic to remove validator from
|
|
"""
|
|
self.topic_validators.pop(topic, None)
|
|
|
|
def get_msg_validators(self, msg: rpc_pb2.Message) -> Tuple[TopicValidator, ...]:
|
|
"""
|
|
Get all validators corresponding to the topics in the message.
|
|
|
|
:param msg: the message published to the topic
|
|
"""
|
|
return tuple(
|
|
self.topic_validators[topic]
|
|
for topic in msg.topicIDs
|
|
if topic in self.topic_validators
|
|
)
|
|
|
|
async def stream_handler(self, stream: INetStream) -> None:
|
|
"""
|
|
Stream handler for pubsub. Gets invoked whenever a new stream is
|
|
created on one of the supported pubsub protocols.
|
|
|
|
:param stream: newly created stream
|
|
"""
|
|
peer_id = stream.muxed_conn.peer_id
|
|
|
|
try:
|
|
await self.continuously_read_stream(stream)
|
|
except (StreamEOF, StreamReset, ParseError, IncompleteReadError) as error:
|
|
logger.debug(
|
|
"fail to read from peer %s, error=%s,"
|
|
"closing the stream and remove the peer from record",
|
|
peer_id,
|
|
error,
|
|
)
|
|
await stream.reset()
|
|
self._handle_dead_peer(peer_id)
|
|
|
|
async def _handle_new_peer(self, peer_id: ID) -> None:
|
|
try:
|
|
stream: INetStream = await self.host.new_stream(peer_id, self.protocols)
|
|
except SwarmException as error:
|
|
logger.debug("fail to add new peer %s, error %s", peer_id, error)
|
|
return
|
|
|
|
self.peers[peer_id] = stream
|
|
|
|
# Send hello packet
|
|
hello = self.get_hello_packet()
|
|
try:
|
|
await stream.write(encode_varint_prefixed(hello.SerializeToString()))
|
|
except StreamClosed:
|
|
logger.debug("Fail to add new peer %s: stream closed", peer_id)
|
|
del self.peers[peer_id]
|
|
return
|
|
# TODO: Check if the peer in black list.
|
|
try:
|
|
self.router.add_peer(peer_id, stream.get_protocol())
|
|
except Exception as error:
|
|
logger.debug("fail to add new peer %s, error %s", peer_id, error)
|
|
del self.peers[peer_id]
|
|
return
|
|
|
|
logger.debug("added new peer %s", peer_id)
|
|
|
|
def _handle_dead_peer(self, peer_id: ID) -> None:
|
|
if peer_id not in self.peers:
|
|
return
|
|
del self.peers[peer_id]
|
|
|
|
for topic in self.peer_topics:
|
|
if peer_id in self.peer_topics[topic]:
|
|
# Delete the entry if no other peers left
|
|
if len(self.peer_topics[topic]) == 1:
|
|
del self.peer_topics[topic]
|
|
else:
|
|
self.peer_topics[topic].remove(peer_id)
|
|
|
|
self.router.remove_peer(peer_id)
|
|
|
|
logger.debug("removed dead peer %s", peer_id)
|
|
|
|
async def handle_peer_queue(self) -> None:
|
|
"""
|
|
Continuously read from peer queue and each time a new peer is found,
|
|
open a stream to the peer using a supported pubsub protocol
|
|
pubsub protocols we support
|
|
"""
|
|
while True:
|
|
peer_id: ID = await self.peer_queue.get()
|
|
# Add Peer
|
|
self._tasks.append(asyncio.ensure_future(self._handle_new_peer(peer_id)))
|
|
|
|
async def handle_dead_peer_queue(self) -> None:
|
|
"""Continuously read from dead peer queue and close the stream between
|
|
that peer and remove peer info from pubsub and pubsub router."""
|
|
while True:
|
|
peer_id: ID = await self.dead_peer_queue.get()
|
|
# Remove Peer
|
|
self._handle_dead_peer(peer_id)
|
|
|
|
def handle_subscription(
|
|
self, origin_id: ID, sub_message: rpc_pb2.RPC.SubOpts
|
|
) -> None:
|
|
"""
|
|
Handle an incoming subscription message from a peer. Update internal
|
|
mapping to mark the peer as subscribed or unsubscribed to topics as
|
|
defined in the subscription message.
|
|
|
|
:param origin_id: id of the peer who subscribe to the message
|
|
:param sub_message: RPC.SubOpts
|
|
"""
|
|
if sub_message.subscribe:
|
|
if sub_message.topicid not in self.peer_topics:
|
|
self.peer_topics[sub_message.topicid] = [origin_id]
|
|
elif origin_id not in self.peer_topics[sub_message.topicid]:
|
|
# Add peer to topic
|
|
self.peer_topics[sub_message.topicid].append(origin_id)
|
|
else:
|
|
if sub_message.topicid in self.peer_topics:
|
|
if origin_id in self.peer_topics[sub_message.topicid]:
|
|
# Delete the entry if no other peers left
|
|
if len(self.peer_topics[sub_message.topicid]) == 1:
|
|
del self.peer_topics[sub_message.topicid]
|
|
else:
|
|
self.peer_topics[sub_message.topicid].remove(origin_id)
|
|
|
|
# FIXME(mhchia): Change the function name?
|
|
async def handle_talk(self, publish_message: rpc_pb2.Message) -> None:
|
|
"""
|
|
Put incoming message from a peer onto my blocking queue.
|
|
|
|
:param publish_message: RPC.Message format
|
|
"""
|
|
|
|
# Check if this message has any topics that we are subscribed to
|
|
for topic in publish_message.topicIDs:
|
|
if topic in self.my_topics:
|
|
# we are subscribed to a topic this message was sent for,
|
|
# so add message to the subscription output queue
|
|
# for each topic
|
|
await self.my_topics[topic].put(publish_message)
|
|
|
|
async def subscribe(self, topic_id: str) -> "asyncio.Queue[rpc_pb2.Message]":
|
|
"""
|
|
Subscribe ourself to a topic.
|
|
|
|
:param topic_id: topic_id to subscribe to
|
|
"""
|
|
|
|
logger.debug("subscribing to topic %s", topic_id)
|
|
|
|
# Already subscribed
|
|
if topic_id in self.my_topics:
|
|
return self.my_topics[topic_id]
|
|
|
|
# Map topic_id to blocking queue
|
|
self.my_topics[topic_id] = asyncio.Queue()
|
|
|
|
# Create subscribe message
|
|
packet: rpc_pb2.RPC = rpc_pb2.RPC()
|
|
packet.subscriptions.extend(
|
|
[rpc_pb2.RPC.SubOpts(subscribe=True, topicid=topic_id)]
|
|
)
|
|
|
|
# Send out subscribe message to all peers
|
|
await self.message_all_peers(packet.SerializeToString())
|
|
|
|
# Tell router we are joining this topic
|
|
await self.router.join(topic_id)
|
|
|
|
# Return the asyncio queue for messages on this topic
|
|
return self.my_topics[topic_id]
|
|
|
|
async def unsubscribe(self, topic_id: str) -> None:
|
|
"""
|
|
Unsubscribe ourself from a topic.
|
|
|
|
:param topic_id: topic_id to unsubscribe from
|
|
"""
|
|
|
|
logger.debug("unsubscribing from topic %s", topic_id)
|
|
|
|
# Return if we already unsubscribed from the topic
|
|
if topic_id not in self.my_topics:
|
|
return
|
|
# Remove topic_id from map if present
|
|
del self.my_topics[topic_id]
|
|
|
|
# Create unsubscribe message
|
|
packet: rpc_pb2.RPC = rpc_pb2.RPC()
|
|
packet.subscriptions.extend(
|
|
[rpc_pb2.RPC.SubOpts(subscribe=False, topicid=topic_id)]
|
|
)
|
|
|
|
# Send out unsubscribe message to all peers
|
|
await self.message_all_peers(packet.SerializeToString())
|
|
|
|
# Tell router we are leaving this topic
|
|
await self.router.leave(topic_id)
|
|
|
|
async def message_all_peers(self, raw_msg: bytes) -> None:
|
|
"""
|
|
Broadcast a message to peers.
|
|
|
|
:param raw_msg: raw contents of the message to broadcast
|
|
"""
|
|
|
|
# Broadcast message
|
|
for stream in self.peers.values():
|
|
# Write message to stream
|
|
try:
|
|
await stream.write(encode_varint_prefixed(raw_msg))
|
|
except StreamClosed:
|
|
peer_id = stream.muxed_conn.peer_id
|
|
logger.debug("Fail to message peer %s: stream closed", peer_id)
|
|
self._handle_dead_peer(peer_id)
|
|
|
|
async def publish(self, topic_id: str, data: bytes) -> None:
|
|
"""
|
|
Publish data to a topic.
|
|
|
|
:param topic_id: topic which we are going to publish the data to
|
|
:param data: data which we are publishing
|
|
"""
|
|
msg = rpc_pb2.Message(
|
|
data=data,
|
|
topicIDs=[topic_id],
|
|
# Origin is ourself.
|
|
from_id=self.host.get_id().to_bytes(),
|
|
seqno=self._next_seqno(),
|
|
)
|
|
|
|
if self.strict_signing:
|
|
priv_key = self.sign_key
|
|
signature = priv_key.sign(
|
|
PUBSUB_SIGNING_PREFIX.encode() + msg.SerializeToString()
|
|
)
|
|
msg.key = self.host.get_public_key().serialize()
|
|
msg.signature = signature
|
|
|
|
await self.push_msg(self.host.get_id(), msg)
|
|
|
|
logger.debug("successfully published message %s", msg)
|
|
|
|
async def validate_msg(self, msg_forwarder: ID, msg: rpc_pb2.Message) -> None:
|
|
"""
|
|
Validate the received message.
|
|
|
|
:param msg_forwarder: the peer who forward us the message.
|
|
:param msg: the message.
|
|
"""
|
|
sync_topic_validators = []
|
|
async_topic_validator_futures: List[Awaitable[bool]] = []
|
|
for topic_validator in self.get_msg_validators(msg):
|
|
if topic_validator.is_async:
|
|
async_topic_validator_futures.append(
|
|
cast(Awaitable[bool], topic_validator.validator(msg_forwarder, msg))
|
|
)
|
|
else:
|
|
sync_topic_validators.append(
|
|
cast(SyncValidatorFn, topic_validator.validator)
|
|
)
|
|
|
|
for validator in sync_topic_validators:
|
|
if not validator(msg_forwarder, msg):
|
|
raise ValidationError(f"Validation failed for msg={msg}")
|
|
|
|
# TODO: Implement throttle on async validators
|
|
|
|
if len(async_topic_validator_futures) > 0:
|
|
results = await asyncio.gather(*async_topic_validator_futures)
|
|
if not all(results):
|
|
raise ValidationError(f"Validation failed for msg={msg}")
|
|
|
|
async def push_msg(self, msg_forwarder: ID, msg: rpc_pb2.Message) -> None:
|
|
"""
|
|
Push a pubsub message to others.
|
|
|
|
:param msg_forwarder: the peer who forward us the message.
|
|
:param msg: the message we are going to push out.
|
|
"""
|
|
logger.debug("attempting to publish message %s", msg)
|
|
|
|
# TODO: Check if the `source` is in the blacklist. If yes, reject.
|
|
|
|
# TODO: Check if the `from` is in the blacklist. If yes, reject.
|
|
|
|
# If the message is processed before, return(i.e., don't further process the message).
|
|
if self._is_msg_seen(msg):
|
|
return
|
|
|
|
# Check if signing is required and if so validate the signature
|
|
if self.strict_signing:
|
|
# Validate the signature of the message
|
|
if not signature_validator(msg):
|
|
logger.debug("Signature validation failed for msg: %s", msg)
|
|
return
|
|
|
|
# Validate the message with registered topic validators.
|
|
# If the validation failed, return(i.e., don't further process the message).
|
|
try:
|
|
await self.validate_msg(msg_forwarder, msg)
|
|
except ValidationError:
|
|
logger.debug(
|
|
"Topic validation failed: sender %s sent data %s under topic IDs: %s",
|
|
f"{base58.b58encode(msg.from_id).decode()}:{msg.seqno.hex()}",
|
|
msg.data.hex(),
|
|
msg.topicIDs,
|
|
)
|
|
return
|
|
|
|
self._mark_msg_seen(msg)
|
|
await self.handle_talk(msg)
|
|
await self.router.publish(msg_forwarder, msg)
|
|
|
|
def _next_seqno(self) -> bytes:
|
|
"""Make the next message sequence id."""
|
|
self.counter += 1
|
|
return self.counter.to_bytes(8, "big")
|
|
|
|
def _is_msg_seen(self, msg: rpc_pb2.Message) -> bool:
|
|
msg_id = get_msg_id(msg)
|
|
return msg_id in self.seen_messages
|
|
|
|
def _mark_msg_seen(self, msg: rpc_pb2.Message) -> None:
|
|
msg_id = get_msg_id(msg)
|
|
# FIXME: Mapping `msg_id` to `1` is quite awkward. Should investigate if there is a
|
|
# more appropriate way.
|
|
self.seen_messages[msg_id] = 1
|
|
|
|
def _is_subscribed_to_msg(self, msg: rpc_pb2.Message) -> bool:
|
|
if not self.my_topics:
|
|
return False
|
|
return any(topic in self.my_topics for topic in msg.topicIDs)
|
|
|
|
async def close(self) -> None:
|
|
for task in self._tasks:
|
|
task.cancel()
|
|
try:
|
|
await task
|
|
except asyncio.CancelledError:
|
|
pass
|