hub/scribe/hub/udp.py
Jack Robison ca2ca23892
cleanup
2022-03-24 12:54:22 -04:00

239 lines
7.7 KiB
Python

import asyncio
import struct
from time import perf_counter
import logging
from typing import Optional, Tuple, NamedTuple
from scribe.schema.attrs import country_str_to_int, country_int_to_str
from scribe.common import LRUCache, is_valid_public_ipv4
log = logging.getLogger(__name__)
_MAGIC = 1446058291 # genesis blocktime (which is actually wrong)
# ping_count_metric = Counter("ping_count", "Number of pings received", namespace='wallet_server_status')
_PAD_BYTES = b'\x00' * 64
PROTOCOL_VERSION = 1
class SPVPing(NamedTuple):
magic: int
protocol_version: int
pad_bytes: bytes
def encode(self):
return struct.pack(b'!lB64s', *self)
@staticmethod
def make() -> bytes:
return SPVPing(_MAGIC, PROTOCOL_VERSION, _PAD_BYTES).encode()
@classmethod
def decode(cls, packet: bytes):
decoded = cls(*struct.unpack(b'!lB64s', packet[:69]))
if decoded.magic != _MAGIC:
raise ValueError("invalid magic bytes")
return decoded
PONG_ENCODING = b'!BBL32s4sH'
class SPVPong(NamedTuple):
protocol_version: int
flags: int
height: int
tip: bytes
source_address_raw: bytes
country: int
def encode(self):
return struct.pack(PONG_ENCODING, *self)
@staticmethod
def encode_address(address: str):
return bytes(int(b) for b in address.split("."))
@classmethod
def make(cls, flags: int, height: int, tip: bytes, source_address: str, country: str) -> bytes:
return SPVPong(
PROTOCOL_VERSION, flags, height, tip,
cls.encode_address(source_address),
country_str_to_int(country)
).encode()
@classmethod
def make_sans_source_address(cls, flags: int, height: int, tip: bytes, country: str) -> Tuple[bytes, bytes]:
pong = cls.make(flags, height, tip, '0.0.0.0', country)
return pong[:38], pong[42:]
@classmethod
def decode(cls, packet: bytes):
return cls(*struct.unpack(PONG_ENCODING, packet[:44]))
@property
def available(self) -> bool:
return (self.flags & 0b00000001) > 0
@property
def ip_address(self) -> str:
return ".".join(map(str, self.source_address_raw))
@property
def country_name(self):
return country_int_to_str(self.country)
def __repr__(self) -> str:
return f"SPVPong(external_ip={self.ip_address}, version={self.protocol_version}, " \
f"available={'True' if self.flags & 1 > 0 else 'False'}," \
f" height={self.height}, tip={self.tip[::-1].hex()}, country={self.country_name})"
class SPVServerStatusProtocol(asyncio.DatagramProtocol):
def __init__(
self, height: int, tip: bytes, country: str,
throttle_cache_size: int = 1024, throttle_reqs_per_sec: int = 10,
allow_localhost: bool = False, allow_lan: bool = False
):
super().__init__()
self.transport: Optional[asyncio.transports.DatagramTransport] = None
self._height = height
self._tip = tip
self._flags = 0
self._country = country
self._left_cache = self._right_cache = None
self.update_cached_response()
self._throttle = LRUCache(throttle_cache_size)
self._should_log = LRUCache(throttle_cache_size)
self._min_delay = 1 / throttle_reqs_per_sec
self._allow_localhost = allow_localhost
self._allow_lan = allow_lan
self.closed = asyncio.Event()
def update_cached_response(self):
self._left_cache, self._right_cache = SPVPong.make_sans_source_address(
self._flags, max(0, self._height), self._tip, self._country
)
def set_unavailable(self):
self._flags &= 0b11111110
self.update_cached_response()
def set_available(self):
self._flags |= 0b00000001
self.update_cached_response()
def set_height(self, height: int, tip: bytes):
self._height, self._tip = height, tip
self.update_cached_response()
def should_throttle(self, host: str):
now = perf_counter()
last_requested = self._throttle.get(host, default=0)
self._throttle[host] = now
if now - last_requested < self._min_delay:
log_cnt = self._should_log.get(host, default=0) + 1
if log_cnt % 100 == 0:
log.warning("throttle spv status to %s", host)
self._should_log[host] = log_cnt
return True
return False
def make_pong(self, host):
return self._left_cache + SPVPong.encode_address(host) + self._right_cache
def datagram_received(self, data: bytes, addr: Tuple[str, int]):
if self.should_throttle(addr[0]):
return
try:
SPVPing.decode(data)
except (ValueError, struct.error, AttributeError, TypeError):
# log.exception("derp")
return
if addr[1] >= 1024 and is_valid_public_ipv4(
addr[0], allow_localhost=self._allow_localhost, allow_lan=self._allow_lan):
self.transport.sendto(self.make_pong(addr[0]), addr)
else:
log.warning("odd packet from %s:%i", addr[0], addr[1])
# ping_count_metric.inc()
def connection_made(self, transport) -> None:
self.transport = transport
self.closed.clear()
def connection_lost(self, exc: Optional[Exception]) -> None:
self.transport = None
self.closed.set()
async def close(self):
if self.transport:
self.transport.close()
await self.closed.wait()
class StatusServer:
def __init__(self):
self._protocol: Optional[SPVServerStatusProtocol] = None
async def start(self, height: int, tip: bytes, country: str, interface: str, port: int, allow_lan: bool = False):
if self.is_running:
return
loop = asyncio.get_event_loop()
interface = interface if interface.lower() != 'localhost' else '127.0.0.1'
self._protocol = SPVServerStatusProtocol(
height, tip, country, allow_localhost=interface == '127.0.0.1', allow_lan=allow_lan
)
await loop.create_datagram_endpoint(lambda: self._protocol, (interface, port))
log.info("started udp status server on %s:%i", interface, port)
async def stop(self):
if self.is_running:
await self._protocol.close()
self._protocol = None
@property
def is_running(self):
return self._protocol is not None
def set_unavailable(self):
if self.is_running:
self._protocol.set_unavailable()
def set_available(self):
if self.is_running:
self._protocol.set_available()
def set_height(self, height: int, tip: bytes):
if self.is_running:
self._protocol.set_height(height, tip)
class SPVStatusClientProtocol(asyncio.DatagramProtocol):
def __init__(self, responses: asyncio.Queue):
super().__init__()
self.transport: Optional[asyncio.transports.DatagramTransport] = None
self.responses = responses
self._ping_packet = SPVPing.make()
def datagram_received(self, data: bytes, addr: Tuple[str, int]):
try:
self.responses.put_nowait(((addr, perf_counter()), SPVPong.decode(data)))
except (ValueError, struct.error, AttributeError, TypeError, RuntimeError):
return
def connection_made(self, transport) -> None:
self.transport = transport
def connection_lost(self, exc: Optional[Exception]) -> None:
self.transport = None
log.info("closed udp spv server selection client")
def ping(self, server: Tuple[str, int]):
self.transport.sendto(self._ping_packet, server)
def close(self):
# log.info("close udp client")
if self.transport:
self.transport.close()