# Copyright (c) 2016-2017, Neil Booth # # All rights reserved. # # See the file "LICENCE" for information about the copyright # and warranty status of this software. '''Classes for local RPC server and remote client TCP/SSL servers.''' import codecs import itertools import time from functools import partial from aiorpcx import ServerSession, JSONRPCAutoDetect, RPCError from lib.hash import sha256, hash_to_str import lib.util as util from server.daemon import DaemonError import server.version as version BAD_REQUEST = 1 DAEMON_ERROR = 2 class Semaphores(object): def __init__(self, semaphores): self.semaphores = semaphores self.acquired = [] async def __aenter__(self): for semaphore in self.semaphores: await semaphore.acquire() self.acquired.append(semaphore) async def __aexit__(self, exc_type, exc_value, traceback): for semaphore in self.acquired: semaphore.release() class SessionBase(ServerSession): '''Base class of ElectrumX JSON sessions. Each session runs its tasks in asynchronous parallelism with other sessions. ''' MAX_CHUNK_SIZE = 2016 session_counter = itertools.count() def __init__(self, controller, kind): super().__init__(rpc_protocol=JSONRPCAutoDetect) self.kind = kind # 'RPC', 'TCP' etc. self.controller = controller self.bp = controller.bp self.env = controller.env self.daemon = self.bp.daemon self.client = 'unknown' self.client_version = (1, ) self.anon_logs = self.env.anon_logs self.txs_sent = 0 self.log_me = False self.bw_limit = self.env.bandwidth_limit self._orig_mr = self.rpc.message_received def peer_address_str(self, *, for_log=True): '''Returns the peer's IP address and port as a human-readable string, respecting anon logs if the output is for a log.''' if for_log and self.anon_logs: return 'xx.xx.xx.xx:xx' return super().peer_address_str() def message_received(self, message): self.logger.info(f'processing {message}') self._orig_mr(message) def toggle_logging(self): self.log_me = not self.log_me if self.log_me: self.rpc.message_received = self.message_received else: self.rpc.message_received = self._orig_mr def flags(self): '''Status flags.''' status = self.kind[0] if self.is_closing(): status += 'C' if self.log_me: status += 'L' status += str(self.concurrency.max_concurrent) return status def connection_made(self, transport): '''Handle an incoming client connection.''' super().connection_made(transport) self.session_id = next(self.session_counter) context = {'conn_id': f'{self.session_id}'} self.logger = util.ConnectionLogger(self.logger, context) self.rpc.logger = self.logger self.group = self.controller.add_session(self) self.logger.info(f'{self.kind} {self.peer_address_str()}, ' f'{len(self.controller.sessions):,d} total') def connection_lost(self, exc): '''Handle client disconnection.''' super().connection_lost(exc) self.controller.remove_session(self) msg = '' if self.paused: msg += ' whilst paused' if self.concurrency.max_concurrent != self.max_concurrent: msg += ' whilst throttled' if self.send_size >= 1024*1024: msg += ('. Sent {:,d} bytes in {:,d} messages' .format(self.send_size, self.send_count)) if msg: msg = 'disconnected' + msg self.logger.info(msg) self.group = None def count_pending_items(self): return self.rpc.pending_requests def semaphore(self): return Semaphores([self.concurrency.semaphore, self.group.semaphore]) def sub_count(self): return 0 class ElectrumX(SessionBase): '''A TCP server that handles incoming Electrum connections.''' def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.subscribe_headers = False self.subscribe_headers_raw = False self.subscribe_height = False self.notified_height = None self.max_response_size = self.env.max_send self.max_subs = self.env.max_session_subs self.hashX_subs = {} self.mempool_statuses = {} self.protocol_version = None self.set_protocol_handlers((1, 0)) def sub_count(self): return len(self.hashX_subs) async def notify_async(self, our_touched): changed = {} for hashX in our_touched: alias = self.hashX_subs[hashX] status = await self.address_status(hashX) changed[alias] = status # Check mempool hashXs - the status is a function of the # confirmed state of other transactions. Note: we cannot # iterate over mempool_statuses as it changes size. for hashX in set(self.mempool_statuses): old_status = self.mempool_statuses[hashX] status = await self.address_status(hashX) if status != old_status: alias = self.hashX_subs[hashX] changed[alias] = status for alias, status in changed.items(): if len(alias) == 64: method = 'blockchain.scripthash.subscribe' else: method = 'blockchain.address.subscribe' self.send_notification(method, (alias, status)) if changed: es = '' if len(changed) == 1 else 'es' self.logger.info('notified of {:,d} address{}' .format(len(changed), es)) def notify(self, height, touched): '''Notify the client about changes to touched addresses (from mempool updates or new blocks) and height. Return the set of addresses the session needs to be asyncronously notified about. This can be empty if there are possible mempool status updates. Returns None if nothing needs to be notified asynchronously. ''' height_changed = height != self.notified_height if height_changed: self.notified_height = height if self.subscribe_headers: args = (self.subscribe_headers_result(height), ) self.send_notification('blockchain.headers.subscribe', args) if self.subscribe_height: args = (height, ) self.send_notification('blockchain.numblocks.subscribe', args) our_touched = touched.intersection(self.hashX_subs) if our_touched or (height_changed and self.mempool_statuses): return our_touched return None def height(self): '''Return the current flushed database height.''' return self.bp.db_height def assert_boolean(self, value): '''Return param value it is boolean otherwise raise an RPCError.''' if value in (False, True): return value raise RPCError(BAD_REQUEST, f'{value} should be a boolean value') def subscribe_headers_result(self, height): '''The result of a header subscription for the given height.''' if self.subscribe_headers_raw: raw_header = self.controller.raw_header(height) return {'hex': raw_header.hex(), 'height': height} return self.controller.electrum_header(height) def headers_subscribe(self, raw=False): '''Subscribe to get headers of new blocks.''' self.subscribe_headers = True self.subscribe_headers_raw = self.assert_boolean(raw) self.notified_height = self.height() return self.subscribe_headers_result(self.height()) def numblocks_subscribe(self): '''Subscribe to get height of new blocks.''' self.subscribe_height = True return self.height() async def add_peer(self, features): '''Add a peer (but only if the peer resolves to the source).''' peer_mgr = self.controller.peer_mgr return await peer_mgr.on_add_peer(features, self.peer_address()) def peers_subscribe(self): '''Return the server peers as a list of (ip, host, details) tuples.''' return self.controller.peer_mgr.on_peers_subscribe(self.is_tor()) async def address_status(self, hashX): '''Returns an address status. Status is a hex string, but must be None if there is no history. ''' # Note history is ordered and mempool unordered in electrum-server # For mempool, height is -1 if unconfirmed txins, otherwise 0 history = await self.controller.get_history(hashX) mempool = await self.controller.mempool_transactions(hashX) status = ''.join('{}:{:d}:'.format(hash_to_str(tx_hash), height) for tx_hash, height in history) status += ''.join('{}:{:d}:'.format(hex_hash, -unconfirmed) for hex_hash, tx_fee, unconfirmed in mempool) if status: status = sha256(status.encode()).hex() else: status = None if mempool: self.mempool_statuses[hashX] = status else: self.mempool_statuses.pop(hashX, None) return status async def hashX_subscribe(self, hashX, alias): # First check our limit. if len(self.hashX_subs) >= self.max_subs: raise RPCError(BAD_REQUEST, 'your address subscription limit ' f'{self.max_subs:,d} reached') # Now let the controller check its limit self.controller.new_subscription() self.hashX_subs[hashX] = alias return await self.address_status(hashX) async def address_subscribe(self, address): '''Subscribe to an address. address: the address to subscribe to''' hashX = self.controller.address_to_hashX(address) return await self.hashX_subscribe(hashX, address) async def scripthash_subscribe(self, scripthash): '''Subscribe to a script hash. scripthash: the SHA256 hash of the script to subscribe to''' hashX = self.controller.scripthash_to_hashX(scripthash) return await self.hashX_subscribe(hashX, scripthash) def server_features(self): '''Returns a dictionary of server features.''' return self.env.server_features() def block_headers(self, start_height, count): '''Return count concatenated block headers as hex for the main chain; starting at start_height. start_height and count must be non-negative integers. At most MAX_CHUNK_SIZE headers will be returned. ''' start_height = self.controller.non_negative_integer(start_height) count = self.controller.non_negative_integer(count) count = min(count, self.MAX_CHUNK_SIZE) hex_str, n = self.controller.block_headers(start_height, count) return {'hex': hex_str, 'count': n, 'max': self.MAX_CHUNK_SIZE} def block_get_chunk(self, index): '''Return a chunk of block headers as a hexadecimal string. index: the chunk index''' index = self.controller.non_negative_integer(index) chunk_size = self.controller.coin.CHUNK_SIZE start_height = index * chunk_size hex_str, n = self.controller.block_headers(start_height, chunk_size) return hex_str def is_tor(self): '''Try to detect if the connection is to a tor hidden service we are running.''' peername = self.controller.peer_mgr.proxy_peername() if not peername: return False peer_address = self.peer_address() return peer_address and peer_address[0] == peername[0] async def replaced_banner(self, banner): network_info = await self.controller.daemon_request('getnetworkinfo') ni_version = network_info['version'] major, minor = divmod(ni_version, 1000000) minor, revision = divmod(minor, 10000) revision //= 100 daemon_version = '{:d}.{:d}.{:d}'.format(major, minor, revision) server_version = version.VERSION.split()[-1] for pair in [ ('$VERSION', version.VERSION), # legacy ('$SERVER_VERSION', server_version), ('$SERVER_SUBVERSION', version.VERSION), ('$DAEMON_VERSION', daemon_version), ('$DAEMON_SUBVERSION', network_info['subversion']), ('$DONATION_ADDRESS', self.env.donation_address), ]: banner = banner.replace(*pair) return banner def donation_address(self): '''Return the donation address as a string, empty if there is none.''' return self.env.donation_address async def banner(self): '''Return the server banner text.''' banner = 'Welcome to Electrum!' if self.is_tor(): banner_file = self.env.tor_banner_file else: banner_file = self.env.banner_file if banner_file: try: with codecs.open(banner_file, 'r', 'utf-8') as f: banner = f.read() except Exception as e: self.loggererror(f'reading banner file {banner_file}: {e}') else: banner = await self.replaced_banner(banner) return banner def ping(self): '''Serves as a connection keep-alive mechanism and for the client to confirm the server is still responding. ''' return None def server_version(self, client_name=None, protocol_version=None): '''Returns the server version as a string. client_name: a string identifying the client protocol_version: the protocol version spoken by the client ''' if client_name: if self.env.drop_client is not None and \ self.env.drop_client.match(client_name): self.close_after_send = True raise RPCError(BAD_REQUEST, f'unsupported client: {client_name}') self.client = str(client_name)[:17] try: self.client_version = tuple(int(part) for part in self.client.split('.')) except Exception: pass # Find the highest common protocol version. Disconnect if # that protocol version in unsupported. ptuple = util.protocol_version(protocol_version, version.PROTOCOL_MIN, version.PROTOCOL_MAX) # From protocol version 1.1, protocol_version cannot be omitted if ptuple is None or (ptuple >= (1, 1) and protocol_version is None): self.logger.info('unsupported protocol version request {}' .format(protocol_version)) self.close_after_send = True raise RPCError(BAD_REQUEST, f'unsupported protocol version: {protocol_version}') self.set_protocol_handlers(ptuple) # The return value depends on the protocol version if ptuple < (1, 1): return version.VERSION else: return (version.VERSION, self.protocol_version) async def transaction_broadcast(self, raw_tx): '''Broadcast a raw transaction to the network. raw_tx: the raw transaction as a hexadecimal string''' # This returns errors as JSON RPC errors, as is natural try: tx_hash = await self.daemon.sendrawtransaction([raw_tx]) self.txs_sent += 1 self.logger.info('sent tx: {}'.format(tx_hash)) self.controller.sent_tx(tx_hash) return tx_hash except DaemonError as e: error, = e.args message = error['message'] self.logger.info('sendrawtransaction: {}'.format(message)) raise RPCError(BAD_REQUEST, 'the transaction was rejected by ' f'network rules.\n\n{message}\n[{raw_tx}]') async def transaction_broadcast_1_0(self, raw_tx): '''Broadcast a raw transaction to the network. raw_tx: the raw transaction as a hexadecimal string''' # An ugly API: current Electrum clients only pass the raw # transaction in hex and expect error messages to be returned in # the result field. And the server shouldn't be doing the client's # user interface job here. try: return await self.transaction_broadcast(raw_tx) except RPCError as e: message = e.msg if 'non-mandatory-script-verify-flag' in message: message = ( 'Your client produced a transaction that is not accepted ' 'by the network any more. Please upgrade to Electrum ' '2.5.1 or newer.' ) return message def set_protocol_handlers(self, ptuple): protocol_version = '.'.join(str(part) for part in ptuple) if protocol_version == self.protocol_version: return self.protocol_version = protocol_version controller = self.controller handlers = { 'blockchain.address.get_balance': controller.address_get_balance, 'blockchain.address.get_history': controller.address_get_history, 'blockchain.address.get_mempool': controller.address_get_mempool, 'blockchain.address.listunspent': controller.address_listunspent, 'blockchain.address.subscribe': self.address_subscribe, 'blockchain.block.get_chunk': self.block_get_chunk, 'blockchain.block.get_header': controller.block_get_header, 'blockchain.estimatefee': controller.estimatefee, 'blockchain.headers.subscribe': self.headers_subscribe, 'blockchain.relayfee': controller.relayfee, 'blockchain.transaction.get_merkle': controller.transaction_get_merkle, 'server.add_peer': self.add_peer, 'server.banner': self.banner, 'server.donation_address': self.donation_address, 'server.features': self.server_features, 'server.peers.subscribe': self.peers_subscribe, 'server.version': self.server_version, } if ptuple < (1, 1): # Methods or semantics unique to 1.0 and earlier protocols handlers.update({ 'blockchain.numblocks.subscribe': self.numblocks_subscribe, 'blockchain.utxo.get_address': controller.utxo_get_address, 'blockchain.transaction.broadcast': self.transaction_broadcast_1_0, 'blockchain.transaction.get': controller.transaction_get_1_0, }) if ptuple >= (1, 1): # New handlers as of 1.1, or different semantics handlers.update({ 'blockchain.scripthash.get_balance': controller.scripthash_get_balance, 'blockchain.scripthash.get_history': controller.scripthash_get_history, 'blockchain.scripthash.get_mempool': controller.scripthash_get_mempool, 'blockchain.scripthash.listunspent': controller.scripthash_listunspent, 'blockchain.scripthash.subscribe': self.scripthash_subscribe, 'blockchain.transaction.broadcast': self.transaction_broadcast, 'blockchain.transaction.get': controller.transaction_get, }) if ptuple >= (1, 2): # New handler as of 1.2 handlers.update({ 'mempool.get_fee_histogram': controller.mempool_get_fee_histogram, 'blockchain.block.headers': self.block_headers, 'server.ping': self.ping, }) self.electrumx_handlers = handlers def request_handler(self, method): '''Return the async handler for the given request method.''' return self.electrumx_handlers.get(method) class LocalRPC(SessionBase): '''A local TCP RPC server session.''' def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.client = 'RPC' self.max_response_size = 0 self.protocol_version = 'RPC' def request_handler(self, method): '''Return the async handler for the given request method.''' return self.controller.rpc_handlers.get(method) class DashElectrumX(ElectrumX): '''A TCP server that handles incoming Electrum Dash connections.''' def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.mns = set() def set_protocol_handlers(self, ptuple): super().set_protocol_handlers(ptuple) mna_broadcast = (self.masternode_announce_broadcast if ptuple >= (1, 1) else self.masternode_announce_broadcast_1_0) self.electrumx_handlers.update({ 'masternode.announce.broadcast': mna_broadcast, 'masternode.subscribe': self.masternode_subscribe, }) def notify(self, height, touched): '''Notify the client about changes in masternode list.''' result = super().notify(height, touched) for masternode in self.mns: status = self.daemon.masternode_list(['status', masternode]) self.send_notification('masternode.subscribe', [masternode, status.get(masternode)]) return result # Masternode command handlers async def masternode_announce_broadcast(self, signmnb): '''Pass through the masternode announce message to be broadcast by the daemon.''' try: return await self.daemon.masternode_broadcast(['relay', signmnb]) except DaemonError as e: error, = e.args message = error['message'] self.logger.info('masternode_broadcast: {}'.format(message)) raise RPCError(BAD_REQUEST, 'the masternode broadcast was ' f'rejected.\n\n{message}\n[{signmnb}]') async def masternode_announce_broadcast_1_0(self, signmnb): '''Pass through the masternode announce message to be broadcast by the daemon.''' # An ugly API, like the old Electrum transaction broadcast API try: return await self.masternode_announce_broadcast(signmnb) except RPCError as e: return e.msg async def masternode_subscribe(self, vin): '''Returns the status of masternode.''' result = await self.daemon.masternode_list(['status', vin]) if result is not None: self.mns.add(vin) return result.get(vin) return None