def handle_hello(self, payload: str) -> None:
""" Executed when a HELLO message is received. It basically
checks the application compatibility.
"""
protocol = self.protocol
try:
data = json.loads(payload)
except ValueError:
protocol.send_error_and_close_connection('Invalid payload.')
return
required_fields = {
'app', 'network', 'remote_address', 'genesis_short_hash',
'timestamp', 'capabilities'
}
# settings_dict is optional
if not set(data).issuperset(required_fields):
# If data does not contain all required fields
protocol.send_error_and_close_connection('Invalid payload.')
return
if settings.ENABLE_PEER_WHITELIST and settings.CAPABILITY_WHITELIST not in data[
'capabilities']:
# If peer is not sending whitelist capability we must close the connection
protocol.send_error_and_close_connection(
'Must have whitelist capability.')
return
if data['app'] != self._app():
self.log.warn('different versions',
theirs=data['app'],
ours=self._app())
if data['network'] != protocol.network:
protocol.send_error_and_close_connection('Wrong network.')
return
if data['genesis_short_hash'] != get_genesis_short_hash():
protocol.send_error_and_close_connection('Different genesis.')
return
if abs(data['timestamp'] - protocol.node.reactor.seconds()
) > settings.MAX_FUTURE_TIMESTAMP_ALLOWED / 2:
protocol.send_error_and_close_connection(
'Nodes timestamps too far apart.')
return
settings_dict = get_settings_hello_dict()
if 'settings_dict' in data and data['settings_dict'] != settings_dict:
# If settings_dict is sent we must validate it
protocol.send_error_and_close_connection(
'Settings values are different. {}'.format(
json.dumps(settings_dict)))
return
protocol.app_version = data['app']
protocol.change_state(protocol.PeerState.PEER_ID)
def _get_hello_data(self) -> Dict[str, Any]:
""" Returns a dict with information about this node that will
be sent to a peer.
"""
protocol = self.protocol
remote = protocol.transport.getPeer()
return {
'app': self._app(),
'network': protocol.network,
'remote_address': '{}:{}'.format(remote.host, remote.port),
'genesis_short_hash': get_genesis_short_hash(),
'timestamp': protocol.node.reactor.seconds(),
'settings_dict': get_settings_hello_dict(),
'capabilities': [],
}
def handle_hello(self, payload: str) -> None:
""" Executed when a HELLO message is received. It basically
checks the application compatibility.
"""
protocol = self.protocol
try:
data = json.loads(payload)
except ValueError:
protocol.send_error_and_close_connection('Invalid payload.')
return
required_fields = {
'app', 'network', 'remote_address', 'genesis_short_hash',
'timestamp', 'capabilities'
}
# settings_dict is optional
if not set(data).issuperset(required_fields):
# If data does not contain all required fields
protocol.send_error_and_close_connection('Invalid payload.')
return
if settings.ENABLE_PEER_WHITELIST and settings.CAPABILITY_WHITELIST not in data[
'capabilities']:
# If peer is not sending whitelist capability we must close the connection
protocol.send_error_and_close_connection(
'Must have whitelist capability.')
return
my_sync_versions = self._get_sync_versions()
try:
remote_sync_versions = _parse_sync_versions(data)
except HathorError as e:
# this will only happen if the remote implementation is wrong
self.log.warn('invalid protocol', error=e)
protocol.send_error_and_close_connection('invalid protocol')
return
common_sync_versions = my_sync_versions & remote_sync_versions
if not common_sync_versions:
# no compatible sync version to use, this is fine though we just can't connect to this peer
self.log.info('no compatible sync version to use')
protocol.send_error_and_close_connection(
'no compatible sync version to use')
return
# choose the best version, sorting is implemented in hathor.p2p.sync_versions.__lt__
protocol.sync_version = max(common_sync_versions)
if data['app'] != self._app():
self.log.warn('different versions',
theirs=data['app'],
ours=self._app())
if data['network'] != protocol.network:
protocol.send_error_and_close_connection('Wrong network.')
return
if data['genesis_short_hash'] != get_genesis_short_hash():
protocol.send_error_and_close_connection('Different genesis.')
return
dt = data['timestamp'] - protocol.node.reactor.seconds()
if abs(dt) > settings.MAX_FUTURE_TIMESTAMP_ALLOWED / 2:
protocol.send_error_and_close_connection(
'Nodes timestamps too far apart.')
return
if 'settings_dict' in data:
# If settings_dict is sent we must validate it
settings_dict = get_settings_hello_dict()
if data['settings_dict'] != settings_dict:
protocol.send_error_and_close_connection(
'Settings values are different. {}'.format(
json.dumps(settings_dict)))
return
protocol.app_version = data['app']
protocol.diff_timestamp = dt
from hathor.p2p.netfilter import get_table
from hathor.p2p.netfilter.context import NetfilterContext
context = NetfilterContext(
protocol=self.protocol,
connections=self.protocol.connections,
addr=self.protocol.transport.getPeer(),
)
verdict = get_table('filter').get_chain('post_hello').process(context)
if not bool(verdict):
self.protocol.disconnect(
'rejected by netfilter: filter post_hello', force=True)
return
protocol.change_state(protocol.PeerState.PEER_ID)