async def handshake(
remote: Node,
privkey: datatypes.PrivateKey,
peer_class: 'Type[BasePeer]',
chaindb: BaseChainDB,
network_id: int,
received_msg_callback: Optional[_ReceivedMsgCallbackType] = None
) -> 'BasePeer':
"""Perform the auth and P2P handshakes with the given remote.
Return an instance of the given peer_class (must be a subclass of BasePeer) connected to that
remote in case both handshakes are successful and at least one of the sub-protocols supported
by peer_class is also supported by the remote.
Raises UnreachablePeer if we cannot connect to the peer or UselessPeer if none of the
sub-protocols supported by us is also supported by the remote.
"""
try:
(aes_secret, mac_secret, egress_mac, ingress_mac, reader,
writer) = await auth.handshake(remote, privkey)
except (ConnectionRefusedError, OSError) as e:
raise UnreachablePeer(e)
peer = peer_class(remote=remote,
privkey=privkey,
reader=reader,
writer=writer,
aes_secret=aes_secret,
mac_secret=mac_secret,
egress_mac=egress_mac,
ingress_mac=ingress_mac,
chaindb=chaindb,
network_id=network_id,
received_msg_callback=received_msg_callback)
peer.base_protocol.send_handshake()
msg = await peer.read_msg()
cmd, decoded = peer.process_msg(msg)
if isinstance(cmd, Disconnect):
# Peers may send a disconnect msg before they send the initial P2P handshake (e.g. when
# they're not accepting more peers), so we special case that here because it's important
# to distinguish this from a failed handshake (e.g. no matching protocols, etc).
decoded = cast(Dict[str, Any], decoded)
raise PeerDisconnected(
"Peer disconnected before completing handshake: {}".format(
decoded['reason_name']))
if len(peer.enabled_sub_protocols) == 0:
raise UselessPeer("No matching sub-protocols")
for proto in peer.enabled_sub_protocols:
proto.send_handshake(peer._local_chain_info)
return peer
async def handshake(remote, privkey, peer_class, chaindb, network_id):
"""Perform the auth and P2P handshakes with the given remote.
Return an instance of the given peer_class (must be a subclass of BasePeer) connected to that
remote in case both handshakes are successful and at least one of the sub-protocols supported
by peer_class is also supported by the remote.
Raises UnreachablePeer if we cannot connect to the peer or UselessPeer if none of the
sub-protocols supported by us is also supported by the remote.
"""
try:
(aes_secret, mac_secret, egress_mac, ingress_mac, reader,
writer) = await auth.handshake(remote, privkey)
except (ConnectionRefusedError, OSError) as e:
raise UnreachablePeer(e)
peer = peer_class(remote=remote,
privkey=privkey,
reader=reader,
writer=writer,
aes_secret=aes_secret,
mac_secret=mac_secret,
egress_mac=egress_mac,
ingress_mac=ingress_mac,
chaindb=chaindb,
network_id=network_id)
peer.base_protocol.send_handshake()
msg = await peer.read_msg()
decoded = peer.process_msg(msg)
if get_devp2p_cmd_id(msg) == Disconnect._cmd_id:
# Peers may send a disconnect msg before they send the initial P2P handshake (e.g. when
# they're not accepting more peers), so we special case that here because it's important
# to distinguish this from a failed handshake (e.g. no matching protocols, etc).
raise PeerDisconnected("{} disconnected before handshake: {}".format(
peer, decoded['reason_name']))
if len(peer.enabled_sub_protocols) == 0:
raise UselessPeer("No matching sub-protocols with {}".format(peer))
for proto in peer.enabled_sub_protocols:
proto.send_handshake(peer.head_info)
return peer
def process_p2p_handshake(self, msg: bytes) -> None:
cmd = self.get_protocol_command_for(msg)
decoded_msg = cmd.handle(msg)
decoded_msg = cast(Dict[str, Any], decoded_msg)
if isinstance(cmd, Disconnect):
# Peers may send a disconnect msg before they send the initial P2P handshake (e.g. when
# they're not accepting more peers), so we special case that here because it's important
# to distinguish this from a failed handshake (e.g. no matching protocols, etc).
raise PeerDisconnected(
"Peer disconnected before completing handshake: {}".format(
decoded_msg['reason_name']))
remote_capabilities = decoded_msg['capabilities']
self.sub_proto = self.select_sub_protocol(remote_capabilities)
if self.sub_proto is None:
self.logger.debug(
"No matching capabilities between us (%s) and %s (%s), disconnecting",
self.capabilities, self.remote, remote_capabilities)
self.disconnect(DisconnectReason.useless_peer)
else:
self.logger.debug(
"Finished P2P handshake with %s, using sub-protocol %s",
self.remote, self.sub_proto)