py-libp2p/libp2p/network/swarm.py

282 lines
10 KiB
Python

import asyncio
import logging
from typing import Dict, List, Optional, Sequence
from multiaddr import Multiaddr
from libp2p.network.connection.net_connection_interface import INetConn
from libp2p.peer.id import ID
from libp2p.peer.peerstore import PeerStoreError
from libp2p.peer.peerstore_interface import IPeerStore
from libp2p.routing.interfaces import IPeerRouting
from libp2p.stream_muxer.abc import IMuxedConn
from libp2p.transport.exceptions import MuxerUpgradeFailure, SecurityUpgradeFailure
from libp2p.transport.listener_interface import IListener
from libp2p.transport.transport_interface import ITransport
from libp2p.transport.upgrader import TransportUpgrader
from libp2p.typing import StreamHandlerFn, TProtocol
from .connection.raw_connection import RawConnection
from .connection.swarm_connection import SwarmConn
from .exceptions import SwarmException
from .network_interface import INetwork
from .notifee_interface import INotifee
from .stream.net_stream_interface import INetStream
logger = logging.getLogger("libp2p.network.swarm")
logger.setLevel(logging.DEBUG)
class Swarm(INetwork):
self_id: ID
peerstore: IPeerStore
upgrader: TransportUpgrader
transport: ITransport
router: IPeerRouting
# TODO: Connection and `peer_id` are 1-1 mapping in our implementation,
# whereas in Go one `peer_id` may point to multiple connections.
connections: Dict[ID, INetConn]
listeners: Dict[str, IListener]
common_stream_handler: Optional[StreamHandlerFn]
notifees: List[INotifee]
def __init__(
self,
peer_id: ID,
peerstore: IPeerStore,
upgrader: TransportUpgrader,
transport: ITransport,
router: IPeerRouting,
):
self.self_id = peer_id
self.peerstore = peerstore
self.upgrader = upgrader
self.transport = transport
self.router = router
self.connections = dict()
self.listeners = dict()
# Create Notifee array
self.notifees = []
self.common_stream_handler = None
def get_peer_id(self) -> ID:
return self.self_id
def set_stream_handler(self, stream_handler: StreamHandlerFn) -> None:
self.common_stream_handler = stream_handler
async def dial_peer(self, peer_id: ID) -> INetConn:
"""
dial_peer try to create a connection to peer_id
:param peer_id: peer if we want to dial
:raises SwarmException: raised when an error occurs
:return: muxed connection
"""
if peer_id in self.connections:
# If muxed connection already exists for peer_id,
# set muxed connection equal to existing muxed connection
return self.connections[peer_id]
logger.debug("attempting to dial peer %s", peer_id)
try:
# Get peer info from peer store
addrs = self.peerstore.addrs(peer_id)
except PeerStoreError:
raise SwarmException(f"No known addresses to peer {peer_id}")
if not addrs:
raise SwarmException(f"No known addresses to peer {peer_id}")
if not self.router:
multiaddr = addrs[0]
else:
multiaddr = self.router.find_peer(peer_id)
# Dial peer (connection to peer does not yet exist)
# Transport dials peer (gets back a raw conn)
raw_conn = await self.transport.dial(multiaddr)
logger.debug("dialed peer %s over base transport", peer_id)
# Per, https://discuss.libp2p.io/t/multistream-security/130, we first secure
# the conn and then mux the conn
try:
secured_conn = await self.upgrader.upgrade_security(raw_conn, peer_id, True)
except SecurityUpgradeFailure as error:
error_msg = "fail to upgrade security for peer %s"
logger.debug(error_msg, peer_id)
await raw_conn.close()
raise SwarmException(error_msg % peer_id) from error
logger.debug("upgraded security for peer %s", peer_id)
try:
muxed_conn = await self.upgrader.upgrade_connection(secured_conn, peer_id)
except MuxerUpgradeFailure as error:
error_msg = "fail to upgrade mux for peer %s"
logger.debug(error_msg, peer_id)
await secured_conn.close()
raise SwarmException(error_msg % peer_id) from error
logger.debug("upgraded mux for peer %s", peer_id)
swarm_conn = await self.add_conn(muxed_conn)
logger.debug("successfully dialed peer %s", peer_id)
return swarm_conn
async def new_stream(
self, peer_id: ID, protocol_ids: Sequence[TProtocol]
) -> INetStream:
"""
:param peer_id: peer_id of destination
:param protocol_id: protocol id
:return: net stream instance
"""
logger.debug(
"attempting to open a stream to peer %s, over one of the protocols %s",
peer_id,
protocol_ids,
)
print(f"!@# swarm.new_stream: 0")
swarm_conn = await self.dial_peer(peer_id)
print(f"!@# swarm.new_stream: 1")
net_stream = await swarm_conn.new_stream()
logger.debug("successfully opened a stream to peer %s", peer_id)
return net_stream
async def listen(self, *multiaddrs: Multiaddr) -> bool:
"""
:param multiaddrs: one or many multiaddrs to start listening on
:return: true if at least one success
For each multiaddr
Check if a listener for multiaddr exists already
If listener already exists, continue
Otherwise:
Capture multiaddr in conn handler
Have conn handler delegate to stream handler
Call listener listen with the multiaddr
Map multiaddr to listener
"""
for maddr in multiaddrs:
if str(maddr) in self.listeners:
return True
async def conn_handler(
reader: asyncio.StreamReader, writer: asyncio.StreamWriter
) -> None:
connection_info = writer.get_extra_info("peername")
# TODO make a proper multiaddr
peer_addr = f"/ip4/{connection_info[0]}/tcp/{connection_info[1]}"
logger.debug("inbound connection at %s", peer_addr)
# logger.debug("inbound connection request", peer_id)
raw_conn = RawConnection(reader, writer, False)
# Per, https://discuss.libp2p.io/t/multistream-security/130, we first secure
# the conn and then mux the conn
try:
# FIXME: This dummy `ID(b"")` for the remote peer is useless.
secured_conn = await self.upgrader.upgrade_security(
raw_conn, ID(b""), False
)
except SecurityUpgradeFailure as error:
error_msg = "fail to upgrade security for peer at %s"
logger.debug(error_msg, peer_addr)
await raw_conn.close()
raise SwarmException(error_msg % peer_addr) from error
peer_id = secured_conn.get_remote_peer()
logger.debug("upgraded security for peer at %s", peer_addr)
logger.debug("identified peer at %s as %s", peer_addr, peer_id)
try:
muxed_conn = await self.upgrader.upgrade_connection(
secured_conn, peer_id
)
except MuxerUpgradeFailure as error:
error_msg = "fail to upgrade mux for peer %s"
logger.debug(error_msg, peer_id)
await secured_conn.close()
raise SwarmException(error_msg % peer_id) from error
logger.debug("upgraded mux for peer %s", peer_id)
await self.add_conn(muxed_conn)
logger.debug("successfully opened connection to peer %s", peer_id)
try:
# Success
listener = self.transport.create_listener(conn_handler)
self.listeners[str(maddr)] = listener
await listener.listen(maddr)
# Call notifiers since event occurred
for notifee in self.notifees:
await notifee.listen(self, maddr)
return True
except IOError:
# Failed. Continue looping.
logger.debug("fail to listen on: " + str(maddr))
# No maddr succeeded
return False
def notify(self, notifee: INotifee) -> bool:
"""
:param notifee: object implementing Notifee interface
:return: true if notifee registered successfully, false otherwise
"""
if isinstance(notifee, INotifee):
self.notifees.append(notifee)
return True
return False
def add_router(self, router: IPeerRouting) -> None:
self.router = router
async def close(self) -> None:
# TODO: Prevent from new listeners and conns being added.
# Reference: https://github.com/libp2p/go-libp2p-swarm/blob/8be680aef8dea0a4497283f2f98470c2aeae6b65/swarm.go#L124-L134 # noqa: E501
# Close listeners
await asyncio.gather(
*[listener.close() for listener in self.listeners.values()]
)
# Close connections
await asyncio.gather(
*[connection.close() for connection in self.connections.values()]
)
logger.debug("swarm successfully closed")
async def close_peer(self, peer_id: ID) -> None:
if peer_id not in self.connections:
return
connection = self.connections[peer_id]
del self.connections[peer_id]
await connection.close()
logger.debug("successfully close the connection to peer %s", peer_id)
async def add_conn(self, muxed_conn: IMuxedConn) -> SwarmConn:
swarm_conn = SwarmConn(muxed_conn, self)
# Store muxed_conn with peer id
self.connections[muxed_conn.peer_id] = swarm_conn
# Call notifiers since event occurred
for notifee in self.notifees:
# TODO: Call with other type of conn?
await notifee.connected(self, muxed_conn)
await swarm_conn.start()
return swarm_conn