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437 | class DirectoryServer:
def __init__(self, settings: DirectoryServerSettings, network: NetworkType, server_nick: str):
self.settings = settings
self.network = network
self.server_nick = server_nick
self.peer_registry = PeerRegistry(max_peers=settings.max_peers)
self.connections = ConnectionPool(max_connections=settings.max_peers)
self.peer_key_to_conn_id: dict[str, str] = {}
self.message_router = MessageRouter(
peer_registry=self.peer_registry,
send_callback=self._send_to_peer,
broadcast_batch_size=settings.broadcast_batch_size,
on_send_failed=self._handle_send_failed,
)
self.handshake_handler = HandshakeHandler(
network=self.network,
server_nick=server_nick,
motd=build_motd(settings.motd),
)
# Rate limit by connection ID to prevent nick spoofing attacks.
# A malicious peer could claim another's nick and spam to get them rate limited.
# Using connection ID ensures each physical connection has its own bucket.
self.rate_limiter = RateLimiter(
rate_limit=settings.message_rate_limit,
burst_limit=settings.message_burst_limit,
disconnect_threshold=settings.rate_limit_disconnect_threshold
if settings.rate_limit_disconnect_threshold > 0
else None,
)
self.server: asyncio.Server | None = None
self._shutdown = False
self._start_time = datetime.now(UTC)
self._client_tasks: set[asyncio.Task[None]] = set()
self.health_server = HealthCheckServer(
host=settings.health_check_host, port=settings.health_check_port
)
async def start(self) -> None:
self.server = await asyncio.start_server(
self._client_connected,
self.settings.host,
self.settings.port,
limit=self.settings.max_message_size,
)
addr = self.server.sockets[0].getsockname()
logger.info(
f"Directory server started on {addr[0]}:{addr[1]} (network: {self.network.value})"
)
self.health_server.start(self)
async with self.server:
await self.server.serve_forever()
async def _client_connected(
self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter
) -> None:
"""Wrapper to track client handler tasks for proper shutdown."""
task = asyncio.current_task()
if task:
self._client_tasks.add(task)
task.add_done_callback(self._client_tasks.discard)
await self._handle_client(reader, writer)
async def stop(self) -> None:
logger.info("Shutting down directory server...")
self._shutdown = True
self.health_server.stop()
# Cancel all client handler tasks before closing server
# This is required for Python 3.12+ where wait_closed() waits for handlers
if self._client_tasks:
logger.debug(f"Cancelling {len(self._client_tasks)} client handler tasks...")
for task in self._client_tasks:
task.cancel()
# Wait for tasks to finish cancellation with timeout
await asyncio.wait(self._client_tasks, timeout=5.0)
self._client_tasks.clear()
if self.server:
self.server.close()
# Use timeout on wait_closed() as safety net for edge cases
try:
await asyncio.wait_for(self.server.wait_closed(), timeout=5.0)
except TimeoutError:
logger.warning("Server wait_closed() timed out after 5s")
await self.connections.close_all()
logger.info("Directory server stopped")
async def _handle_client(
self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter
) -> None:
peer_addr = writer.get_extra_info("peername")
conn_id = f"{peer_addr[0]}:{peer_addr[1]}"
logger.trace(f"New connection from {conn_id}")
transport = writer.transport
# Set reasonable write buffer limits (64KB high, 16KB low)
# This allows some buffering while preventing memory bloat
transport.set_write_buffer_limits(high=65536, low=16384) # type: ignore[union-attr]
sock = transport.get_extra_info("socket")
if sock:
import socket
sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
connection = TCPConnection(reader, writer, self.settings.max_message_size)
peer_key: str | None = None
try:
self.connections.add(conn_id, connection)
peer_key = await self._perform_handshake(connection, conn_id)
if not peer_key:
return
await self._handle_peer_messages(connection, conn_id, peer_key)
except Exception as e:
logger.error(f"Error handling client {conn_id}: {e}")
finally:
await self._cleanup_peer(connection, conn_id, peer_key)
async def _perform_handshake(self, connection: TCPConnection, conn_id: str) -> str | None:
try:
logger.trace(f"[{conn_id}] Waiting for handshake message...")
data = await asyncio.wait_for(connection.receive(), timeout=30.0)
logger.trace(f"[{conn_id}] Received {len(data)} bytes: {data[:200]!r}...")
envelope = MessageEnvelope.from_bytes(
data,
max_line_length=self.settings.max_line_length,
max_json_nesting_depth=self.settings.max_json_nesting_depth,
)
logger.trace(
f"[{conn_id}] Parsed envelope: type={envelope.message_type}, payload_len={len(envelope.payload)}"
)
if envelope.message_type != MessageType.HANDSHAKE:
logger.warning(f"[{conn_id}] Expected handshake, got {envelope.message_type}")
return None
logger.trace(f"[{conn_id}] Processing handshake payload: {envelope.payload[:200]}")
peer_info, response = self.handshake_handler.process_handshake(
envelope.payload, conn_id
)
logger.trace(
f"[{conn_id}] Handshake processed: peer_nick={peer_info.nick}, location={peer_info.location_string}"
)
response_envelope = MessageEnvelope(
message_type=MessageType.DN_HANDSHAKE, payload=json.dumps(response)
)
response_bytes = response_envelope.to_bytes()
logger.trace(f"[{conn_id}] Sending handshake response: {len(response_bytes)} bytes")
logger.trace(f"[{conn_id}] Response content: {response_bytes[:200]!r}...")
try:
await connection.send(response_bytes)
logger.trace(f"[{conn_id}] Handshake response sent successfully")
# Small delay to let client process the handshake response
await asyncio.sleep(0.05)
except Exception as e:
logger.error(f"[{conn_id}] Failed to send handshake response: {e}")
raise
peer_location = peer_info.location_string
self.peer_registry.register(peer_info)
logger.trace(f"[{conn_id}] Peer registered in registry")
peer_key = peer_info.nick if peer_location == "NOT-SERVING-ONION" else peer_location
self.peer_registry.update_status(peer_key, PeerStatus.HANDSHAKED)
self.peer_key_to_conn_id[peer_key] = conn_id
logger.trace(f"[{conn_id}] Peer key mapped: {peer_key}")
logger.trace(f"[{conn_id}] Handshake complete for {peer_key} (nick={peer_info.nick})")
return peer_key
except HandshakeError as e:
logger.warning(f"[{conn_id}] Handshake failed: {e}")
return None
except TimeoutError:
logger.warning(f"[{conn_id}] Handshake timeout (30s)")
return None
except Exception as e:
logger.error(f"[{conn_id}] Handshake error: {e}", exc_info=True)
return None
async def _handle_peer_messages(
self, connection: TCPConnection, conn_id: str, peer_key: str
) -> None:
peer_info = self.peer_registry.get_by_key(peer_key)
if not peer_info:
return
logger.info(f"Peer {peer_info.nick} connected from {peer_info.location_string}")
# Fire-and-forget notification for peer connect
total_peers = self.peer_registry.count()
asyncio.create_task(
get_notifier().notify_peer_connected(
peer_info.nick, peer_info.location_string, total_peers
)
)
while connection.is_connected() and not self._shutdown:
try:
data = await connection.receive()
# Rate limiting by connection ID to prevent nick spoofing attacks.
# A malicious peer could claim another's nick in handshake and spam
# to get the legitimate peer rate-limited. Using conn_id ensures
# each physical connection is rate-limited independently.
action, delay = self.rate_limiter.check(conn_id)
if action == RateLimitAction.DISCONNECT:
violations = self.rate_limiter.get_violation_count(conn_id)
logger.warning(
f"Rate limit exceeded for {peer_info.nick} ({conn_id}): "
f"{violations} violations, disconnecting"
)
# Fire-and-forget notification for rate limit ban
asyncio.create_task(
get_notifier().notify_peer_banned(
peer_info.nick,
"Rate limit exceeded",
self.settings.rate_limit_disconnect_threshold,
)
)
break
elif action == RateLimitAction.DELAY:
violations = self.rate_limiter.get_violation_count(conn_id)
if violations % 50 == 1: # Log every 50th violation to avoid spam
logger.debug(
f"Rate limiting {peer_info.nick} ({conn_id}): "
f"{violations} violations, delay={delay:.2f}s"
)
# Drop message but stay connected - this is the "slowdown" approach
continue
envelope = MessageEnvelope.from_bytes(
data,
max_line_length=self.settings.max_line_length,
max_json_nesting_depth=self.settings.max_json_nesting_depth,
)
await self.message_router.route_message(envelope, peer_key)
except asyncio.CancelledError:
break
except Exception as e:
logger.error(f"Error processing message from {peer_info.nick}: {e}")
break
async def _cleanup_peer(
self, connection: TCPConnection, conn_id: str, peer_key: str | None
) -> None:
if peer_key:
peer_info = self.peer_registry.get_by_key(peer_key)
if peer_info:
logger.info(f"Peer {peer_info.nick} disconnected")
# Fire-and-forget notification for peer disconnect
total_peers = (
self.peer_registry.count() - 1
) # Minus 1 since we're about to unregister
asyncio.create_task(
get_notifier().notify_peer_disconnected(peer_info.nick, total_peers)
)
await self.message_router.broadcast_peer_disconnect(
peer_info.location_string, peer_info.network
)
self.peer_registry.unregister(peer_key)
if peer_key in self.peer_key_to_conn_id:
del self.peer_key_to_conn_id[peer_key]
# Clean up offer tracking
self.message_router.remove_peer_offers(peer_key)
# Clean up rate limiter state (keyed by conn_id, not peer_key)
self.rate_limiter.remove_peer(conn_id)
self.connections.remove(conn_id)
try:
await connection.close()
except Exception as e:
logger.trace(f"Error closing connection: {e}")
async def _send_to_peer(self, peer_location: str, data: bytes) -> None:
peer_key = peer_location
conn_id = self.peer_key_to_conn_id.get(peer_key)
if not conn_id:
raise ValueError(f"No connection for peer: {peer_location}")
connection = self.connections.get(conn_id)
if not connection:
raise ValueError(f"No connection for conn_id: {conn_id}")
await connection.send(data)
async def _handle_send_failed(self, peer_key: str) -> None:
"""
Called when sending to a peer fails.
Removes the peer from both the connection mapping and the registry
to prevent further send attempts to this dead connection.
"""
if peer_key in self.peer_key_to_conn_id:
logger.debug(f"Removing failed peer mapping: {peer_key}")
del self.peer_key_to_conn_id[peer_key]
# Also unregister from peer registry to prevent further routing attempts
peer_info = self.peer_registry.get_by_key(peer_key)
if peer_info:
logger.debug(f"Unregistering failed peer: {peer_key}")
self.peer_registry.unregister(peer_key)
def is_healthy(self) -> bool:
return (
self.server is not None
and not self._shutdown
and self.peer_registry.count() < self.settings.max_peers
)
def get_stats(self) -> dict:
return {
"network": self.network.value,
"connected_peers": self.peer_registry.count(),
"max_peers": self.settings.max_peers,
"active_connections": len(self.connections),
"rate_limit_violations": self.rate_limiter.get_stats()["total_violations"],
}
def get_detailed_stats(self) -> dict:
uptime = (datetime.now(UTC) - self._start_time).total_seconds()
registry_stats = self.peer_registry.get_stats()
connected_peers = self.peer_registry.get_all_connected()
passive_peers = self.peer_registry.get_passive_peers()
active_peers = self.peer_registry.get_active_peers()
offer_stats = self.message_router.get_offer_stats()
return {
"network": self.network.value,
"uptime_seconds": uptime,
"server_status": "running" if not self._shutdown else "stopping",
"max_peers": self.settings.max_peers,
"stats": registry_stats,
"rate_limiter": self.rate_limiter.get_stats(),
"offers": offer_stats,
"connected_peers": {
"total": len(connected_peers),
"nicks": [p.nick for p in connected_peers],
},
"passive_peers": {
"total": len(passive_peers),
"nicks": [p.nick for p in passive_peers],
},
"active_peers": {
"total": len(active_peers),
"nicks": [p.nick for p in active_peers],
},
"active_connections": len(self.connections),
}
def log_status(self) -> None:
stats = self.get_detailed_stats()
logger.info("=== Directory Server Status ===")
logger.info(f"Network: {stats['network']}")
logger.info(f"Uptime: {stats['uptime_seconds']:.0f}s")
logger.info(f"Status: {stats['server_status']}")
logger.info(f"Connected peers: {stats['connected_peers']['total']}/{stats['max_peers']}")
logger.info(f" Nicks: {', '.join(stats['connected_peers']['nicks'][:10])}")
if len(stats["connected_peers"]["nicks"]) > 10:
logger.info(f" ... and {len(stats['connected_peers']['nicks']) - 10} more")
logger.info(f"Passive peers (orderbook watchers): {stats['passive_peers']['total']}")
logger.info(f" Nicks: {', '.join(stats['passive_peers']['nicks'][:10])}")
if len(stats["passive_peers"]["nicks"]) > 10:
logger.info(f" ... and {len(stats['passive_peers']['nicks']) - 10} more")
logger.info(f"Active peers (makers): {stats['active_peers']['total']}")
logger.info(f" Nicks: {', '.join(stats['active_peers']['nicks'][:10])}")
if len(stats["active_peers"]["nicks"]) > 10:
logger.info(f" ... and {len(stats['active_peers']['nicks']) - 10} more")
logger.info(f"Active connections: {stats['active_connections']}")
logger.info("===============================")
|