import logging import asyncio import typing import binascii import contextlib from lbrynet.utils import resolve_host from lbrynet.dht import constants from lbrynet.dht.error import RemoteException from lbrynet.dht.protocol.async_generator_junction import AsyncGeneratorJunction from lbrynet.dht.protocol.distance import Distance from lbrynet.dht.protocol.iterative_find import IterativeNodeFinder, IterativeValueFinder from lbrynet.dht.protocol.protocol import KademliaProtocol from lbrynet.dht.peer import KademliaPeer if typing.TYPE_CHECKING: from lbrynet.dht.peer import PeerManager log = logging.getLogger(__name__) class Node: def __init__(self, loop: asyncio.BaseEventLoop, peer_manager: 'PeerManager', node_id: bytes, udp_port: int, internal_udp_port: int, peer_port: int, external_ip: str, rpc_timeout: typing.Optional[float] = 5.0): self.loop = loop self.internal_udp_port = internal_udp_port self.protocol = KademliaProtocol(loop, peer_manager, node_id, external_ip, udp_port, peer_port, rpc_timeout) self.listening_port: asyncio.DatagramTransport = None self.joined = asyncio.Event(loop=self.loop) self._join_task: asyncio.Task = None self._refresh_task: asyncio.Task = None async def refresh_node(self): while True: # remove peers with expired blob announcements from the datastore self.protocol.data_store.removed_expired_peers() total_peers: typing.List['KademliaPeer'] = [] # add all peers in the routing table total_peers.extend(self.protocol.routing_table.get_peers()) # add all the peers who have announed blobs to us total_peers.extend(self.protocol.data_store.get_storing_contacts()) # get ids falling in the midpoint of each bucket that hasn't been recently updated node_ids = self.protocol.routing_table.get_refresh_list(0, True) # if we have 3 or fewer populated buckets get two random ids in the range of each to try and # populate/split the buckets further buckets_with_contacts = self.protocol.routing_table.buckets_with_contacts() if buckets_with_contacts <= 3: for i in range(buckets_with_contacts): node_ids.append(self.protocol.routing_table.random_id_in_bucket_range(i)) node_ids.append(self.protocol.routing_table.random_id_in_bucket_range(i)) if self.protocol.routing_table.get_peers(): # if we have node ids to look up, perform the iterative search until we have k results while node_ids: peers = await self.peer_search(node_ids.pop()) total_peers.extend(peers) else: fut = asyncio.Future(loop=self.loop) self.loop.call_later(constants.refresh_interval // 4, fut.set_result, None) await fut continue # ping the set of peers; upon success/failure the routing able and last replied/failed time will be updated to_ping = [peer for peer in set(total_peers) if self.protocol.peer_manager.peer_is_good(peer) is not True] if to_ping: await self.protocol.ping_queue.enqueue_maybe_ping(*to_ping, delay=0) fut = asyncio.Future(loop=self.loop) self.loop.call_later(constants.refresh_interval, fut.set_result, None) await fut async def announce_blob(self, blob_hash: str) -> typing.List[bytes]: announced_to_node_ids = [] while not announced_to_node_ids: hash_value = binascii.unhexlify(blob_hash.encode()) assert len(hash_value) == constants.hash_length peers = await self.peer_search(hash_value) if not self.protocol.external_ip: raise Exception("Cannot determine external IP") log.debug("Store to %i peers", len(peers)) for peer in peers: log.debug("store to %s %s %s", peer.address, peer.udp_port, peer.tcp_port) stored_to_tup = await asyncio.gather( *(self.protocol.store_to_peer(hash_value, peer) for peer in peers), loop=self.loop ) announced_to_node_ids.extend([node_id for node_id, contacted in stored_to_tup if contacted]) log.info("Stored %s to %i of %i attempted peers", binascii.hexlify(hash_value).decode()[:8], len(announced_to_node_ids), len(peers)) return announced_to_node_ids def stop(self) -> None: if self.joined.is_set(): self.joined.clear() if self._join_task: self._join_task.cancel() if self._refresh_task and not (self._refresh_task.done() or self._refresh_task.cancelled()): self._refresh_task.cancel() if self.protocol and self.protocol.ping_queue.running: self.protocol.ping_queue.stop() if self.listening_port is not None: self.listening_port.close() self._join_task = None self.listening_port = None log.info("Stopped DHT node") async def start_listening(self, interface: str = '') -> None: if not self.listening_port: self.listening_port, _ = await self.loop.create_datagram_endpoint( lambda: self.protocol, (interface, self.internal_udp_port) ) log.info("DHT node listening on UDP %s:%i", interface, self.internal_udp_port) else: log.warning("Already bound to port %s", self.listening_port) async def join_network(self, interface: typing.Optional[str] = '', known_node_urls: typing.Optional[typing.List[typing.Tuple[str, int]]] = None): if not self.listening_port: await self.start_listening(interface) self.protocol.ping_queue.start() self._refresh_task = self.loop.create_task(self.refresh_node()) # resolve the known node urls known_node_addresses = [] url_to_addr = {} if known_node_urls: for host, port in known_node_urls: address = await resolve_host(host) if (address, port) not in known_node_addresses: known_node_addresses.append((address, port)) url_to_addr[address] = host if known_node_addresses: while not self.protocol.routing_table.get_peers(): success = False # ping the seed nodes, this will set their node ids (since we don't know them ahead of time) for address, port in known_node_addresses: peer = self.protocol.get_rpc_peer(KademliaPeer(self.loop, address, udp_port=port)) try: await peer.ping() success = True except asyncio.TimeoutError: log.warning("seed node (%s:%i) timed out in %s", url_to_addr.get(address, address), port, round(self.protocol.rpc_timeout, 2)) if success: break # now that we have the seed nodes in routing, to an iterative lookup of our own id to populate the buckets # in the routing table with good peers who are near us async with self.peer_search_junction(self.protocol.node_id, max_results=16) as junction: async for peers in junction: for peer in peers: try: await self.protocol.get_rpc_peer(peer).ping() except (asyncio.TimeoutError, RemoteException): pass log.info("Joined DHT, %i peers known in %i buckets", len(self.protocol.routing_table.get_peers()), self.protocol.routing_table.buckets_with_contacts()) self.joined.set() def start(self, interface: str, known_node_urls: typing.List[typing.Tuple[str, int]]): self._join_task = self.loop.create_task( self.join_network( interface=interface, known_node_urls=known_node_urls ) ) def get_iterative_node_finder(self, key: bytes, shortlist: typing.Optional[typing.List] = None, bottom_out_limit: int = constants.bottom_out_limit, max_results: int = constants.k) -> IterativeNodeFinder: return IterativeNodeFinder(self.loop, self.protocol.peer_manager, self.protocol.routing_table, self.protocol, key, bottom_out_limit, max_results, None, shortlist) def get_iterative_value_finder(self, key: bytes, shortlist: typing.Optional[typing.List] = None, bottom_out_limit: int = 40, max_results: int = -1) -> IterativeValueFinder: return IterativeValueFinder(self.loop, self.protocol.peer_manager, self.protocol.routing_table, self.protocol, key, bottom_out_limit, max_results, None, shortlist) @contextlib.asynccontextmanager async def stream_peer_search_junction(self, hash_queue: asyncio.Queue, bottom_out_limit=20, max_results=-1) -> AsyncGeneratorJunction: peer_generator = AsyncGeneratorJunction(self.loop) async def _add_hashes_from_queue(): while True: try: blob_hash = await hash_queue.get() except asyncio.CancelledError: break peer_generator.add_generator( self.get_iterative_value_finder( binascii.unhexlify(blob_hash.encode()), bottom_out_limit=bottom_out_limit, max_results=max_results ) ) add_hashes_task = self.loop.create_task(_add_hashes_from_queue()) try: async with peer_generator as junction: yield junction await peer_generator.finished.wait() except asyncio.CancelledError: if add_hashes_task and not (add_hashes_task.done() or add_hashes_task.cancelled()): add_hashes_task.cancel() raise finally: if add_hashes_task and not (add_hashes_task.done() or add_hashes_task.cancelled()): add_hashes_task.cancel() def peer_search_junction(self, node_id: bytes, max_results=constants.k*2, bottom_out_limit=20) -> AsyncGeneratorJunction: peer_generator = AsyncGeneratorJunction(self.loop) peer_generator.add_generator( self.get_iterative_node_finder( node_id, bottom_out_limit=bottom_out_limit, max_results=max_results ) ) return peer_generator async def peer_search(self, node_id: bytes, count=constants.k, max_results=constants.k*2, bottom_out_limit=20) -> typing.List['KademliaPeer']: accumulated: typing.List['KademliaPeer'] = [] async with self.peer_search_junction(node_id, max_results=max_results, bottom_out_limit=bottom_out_limit) as junction: async for peers in junction: accumulated.extend(peers) distance = Distance(node_id) accumulated.sort(key=lambda peer: distance(peer.node_id)) return accumulated[:count] async def _accumulate_search_junction(self, search_queue: asyncio.Queue, result_queue: asyncio.Queue): try: async with self.stream_peer_search_junction(search_queue) as search_junction: # pylint: disable=E1701 async for peers in search_junction: if peers: result_queue.put_nowait([ peer for peer in peers if not ( peer.address == self.protocol.external_ip and peer.tcp_port == self.protocol.peer_port ) ]) except asyncio.CancelledError: return def accumulate_peers(self, search_queue: asyncio.Queue, peer_queue: typing.Optional[asyncio.Queue] = None) -> typing.Tuple[ asyncio.Queue, asyncio.Task]: q = peer_queue or asyncio.Queue() return q, asyncio.create_task(self._accumulate_search_junction(search_queue, q))