import asyncio import logging import typing import binascii from lbrynet.error import InvalidBlobHashError, InvalidDataError from lbrynet.blob_exchange.serialization import BlobResponse, BlobRequest from lbrynet.utils import cache_concurrent if typing.TYPE_CHECKING: from lbrynet.blob.blob_file import AbstractBlob from lbrynet.blob.writer import HashBlobWriter log = logging.getLogger(__name__) class BlobExchangeClientProtocol(asyncio.Protocol): def __init__(self, loop: asyncio.BaseEventLoop, peer_timeout: typing.Optional[float] = 10): self.loop = loop self.peer_port: typing.Optional[int] = None self.peer_address: typing.Optional[str] = None self.peer_timeout = peer_timeout self.transport: typing.Optional[asyncio.Transport] = None self.writer: typing.Optional['HashBlobWriter'] = None self.blob: typing.Optional['AbstractBlob'] = None self._blob_bytes_received = 0 self._response_fut: typing.Optional[asyncio.Future] = None self.buf = b'' # this is here to handle the race when the downloader is closed right as response_fut gets a result self.closed = asyncio.Event(loop=self.loop) def data_received(self, data: bytes): log.debug("%s:%d -- got %s bytes -- %s bytes on buffer -- %s blob bytes received", self.peer_address, self.peer_port, len(data), len(self.buf), self._blob_bytes_received) if not self.transport or self.transport.is_closing(): log.warning("transport closing, but got more bytes from %s:%i\n%s", self.peer_address, self.peer_port, binascii.hexlify(data)) if self._response_fut and not self._response_fut.done(): self._response_fut.cancel() return if not self._response_fut: log.warning("Protocol received data before expected, probable race on keep alive. Closing transport.") return self.close() if self._blob_bytes_received and not self.writer.closed(): return self._write(data) response = BlobResponse.deserialize(self.buf + data) if not response.responses and not self._response_fut.done(): self.buf += data return else: self.buf = b'' if response.responses and self.blob: blob_response = response.get_blob_response() if blob_response and not blob_response.error and blob_response.blob_hash == self.blob.blob_hash: # set the expected length for the incoming blob if we didn't know it self.blob.set_length(blob_response.length) elif blob_response and not blob_response.error and self.blob.blob_hash != blob_response.blob_hash: # the server started sending a blob we didn't request log.warning("mismatch with self.blob %s", self.blob.blob_hash) return if response.responses: log.debug("got response from %s:%i <- %s", self.peer_address, self.peer_port, response.to_dict()) # fire the Future with the response to our request self._response_fut.set_result(response) if response.blob_data and self.writer and not self.writer.closed(): # log.debug("got %i blob bytes from %s:%i", len(response.blob_data), self.peer_address, self.peer_port) # write blob bytes if we're writing a blob and have blob bytes to write self._write(response.blob_data) def _write(self, data: bytes): if len(data) > (self.blob.get_length() - self._blob_bytes_received): data = data[:(self.blob.get_length() - self._blob_bytes_received)] log.warning("got more than asked from %s:%d, probable sendfile bug", self.peer_address, self.peer_port) else: data = data self._blob_bytes_received += len(data) try: self.writer.write(data) except IOError as err: log.error("error downloading blob from %s:%i: %s", self.peer_address, self.peer_port, err) if self._response_fut and not self._response_fut.done(): self._response_fut.set_exception(err) except (asyncio.TimeoutError) as err: # TODO: is this needed? log.error("%s downloading blob from %s:%i", str(err), self.peer_address, self.peer_port) if self._response_fut and not self._response_fut.done(): self._response_fut.set_exception(err) async def _download_blob(self) -> typing.Tuple[int, typing.Optional[asyncio.Transport]]: """ :return: download success (bool), keep connection (bool) """ request = BlobRequest.make_request_for_blob_hash(self.blob.blob_hash) blob_hash = self.blob.blob_hash try: msg = request.serialize() log.debug("send request to %s:%i -> %s", self.peer_address, self.peer_port, msg.decode()) self.transport.write(msg) response: BlobResponse = await asyncio.wait_for(self._response_fut, self.peer_timeout, loop=self.loop) availability_response = response.get_availability_response() price_response = response.get_price_response() blob_response = response.get_blob_response() if self.closed.is_set(): msg = f"cancelled blob request for {blob_hash} immediately after we got a response" log.warning(msg) raise asyncio.CancelledError(msg) if (not blob_response or blob_response.error) and\ (not availability_response or not availability_response.available_blobs): log.warning("%s not in availability response from %s:%i", self.blob.blob_hash, self.peer_address, self.peer_port) log.warning(response.to_dict()) return self._blob_bytes_received, self.close() elif availability_response.available_blobs and \ availability_response.available_blobs != [self.blob.blob_hash]: log.warning("blob availability response doesn't match our request from %s:%i", self.peer_address, self.peer_port) return self._blob_bytes_received, self.close() if not price_response or price_response.blob_data_payment_rate != 'RATE_ACCEPTED': log.warning("data rate rejected by %s:%i", self.peer_address, self.peer_port) return self._blob_bytes_received, self.close() if not blob_response or blob_response.error: log.warning("blob cant be downloaded from %s:%i", self.peer_address, self.peer_port) return self._blob_bytes_received, self.close() if not blob_response.error and blob_response.blob_hash != self.blob.blob_hash: log.warning("incoming blob hash mismatch from %s:%i", self.peer_address, self.peer_port) return self._blob_bytes_received, self.close() if self.blob.length is not None and self.blob.length != blob_response.length: log.warning("incoming blob unexpected length from %s:%i", self.peer_address, self.peer_port) return self._blob_bytes_received, self.close() msg = f"downloading {self.blob.blob_hash[:8]} from {self.peer_address}:{self.peer_port}," \ f" timeout in {self.peer_timeout}" log.debug(msg) msg = f"downloaded {self.blob.blob_hash[:8]} from {self.peer_address}:{self.peer_port}" await asyncio.wait_for(self.writer.finished, self.peer_timeout, loop=self.loop) log.info(msg) # await self.blob.finished_writing.wait() not necessary, but a dangerous change. TODO: is it needed? return self._blob_bytes_received, self.transport except asyncio.TimeoutError: return self._blob_bytes_received, self.close() except (InvalidBlobHashError, InvalidDataError): log.warning("invalid blob from %s:%i", self.peer_address, self.peer_port) return self._blob_bytes_received, self.close() def close(self): self.closed.set() if self._response_fut and not self._response_fut.done(): self._response_fut.cancel() if self.writer and not self.writer.closed(): self.writer.close_handle() self._response_fut = None self.writer = None self.blob = None if self.transport: self.transport.close() self.transport = None self.buf = b'' async def download_blob(self, blob: 'AbstractBlob') -> typing.Tuple[int, typing.Optional[asyncio.Transport]]: self.closed.clear() blob_hash = blob.blob_hash if blob.get_is_verified() or not blob.is_writeable(): return 0, self.transport try: self._blob_bytes_received = 0 self.blob, self.writer = blob, blob.get_blob_writer(self.peer_address, self.peer_port) self._response_fut = asyncio.Future(loop=self.loop) return await self._download_blob() except OSError as e: # i'm not sure how to fix this race condition - jack log.warning("race happened downloading %s from %s:%i", blob_hash, self.peer_address, self.peer_port) # return self._blob_bytes_received, self.transport raise except asyncio.TimeoutError: if self._response_fut and not self._response_fut.done(): self._response_fut.cancel() self.close() return self._blob_bytes_received, None except asyncio.CancelledError: self.close() raise finally: if self.writer and not self.writer.closed(): self.writer.close_handle() self.writer = None def connection_made(self, transport: asyncio.Transport): self.transport = transport self.peer_address, self.peer_port = self.transport.get_extra_info('peername') log.debug("connection made to %s:%i", self.peer_address, self.peer_port) def connection_lost(self, reason): log.debug("connection lost to %s:%i (reason: %s, %s)", self.peer_address, self.peer_port, str(reason), str(type(reason))) self.close() @cache_concurrent async def request_blob(loop: asyncio.BaseEventLoop, blob: 'AbstractBlob', address: str, tcp_port: int, peer_connect_timeout: float, blob_download_timeout: float, connected_transport: asyncio.Transport = None, connection_id: int = 0)\ -> typing.Tuple[int, typing.Optional[asyncio.Transport]]: """ Returns [, ] """ protocol = BlobExchangeClientProtocol(loop, blob_download_timeout) if connected_transport and not connected_transport.is_closing(): connected_transport.set_protocol(protocol) protocol.connection_made(connected_transport) log.debug("reusing connection for %s:%d", address, tcp_port) else: connected_transport = None try: if not connected_transport: await asyncio.wait_for(loop.create_connection(lambda: protocol, address, tcp_port), peer_connect_timeout, loop=loop) if blob.get_is_verified() or not blob.is_writeable(): # file exists but not verified means someone is writing right now, give it time, come back later return 0, connected_transport return await protocol.download_blob(blob) except (asyncio.TimeoutError, ConnectionRefusedError, ConnectionAbortedError, OSError): return 0, None