# 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 time from functools import partial from lib.hash import sha256, hash_to_str from lib.jsonrpc import JSONSession, RPCError, JSONRPCv2, JSONRPC from server.daemon import DaemonError import server.version as version class SessionBase(JSONSession): '''Base class of ElectrumX JSON sessions. Each session runs its tasks in asynchronous parallelism with other sessions. ''' def __init__(self, controller, kind): # Force v2 as a temporary hack for old Coinomi wallets # Remove in April 2017 super().__init__(version=JSONRPCv2) 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.protocol_version = '1.0' self.anon_logs = self.env.anon_logs self.last_delay = 0 self.txs_sent = 0 self.requests = [] self.start_time = time.time() self.close_time = 0 self.bw_limit = self.env.bandwidth_limit self.bw_time = self.start_time self.bw_interval = 3600 self.bw_used = 0 def close_connection(self): '''Call this to close the connection.''' self.close_time = time.time() super().close_connection() def peername(self, *, for_log=True): '''Return the peer address and port.''' return self.peer_addr(anon=for_log and self.anon_logs) def flags(self): '''Status flags.''' status = self.kind[0] if self.is_closing(): status += 'C' if self.log_me: status += 'L' status += str(self.controller.session_priority(self)) return status def connection_made(self, transport): '''Handle an incoming client connection.''' super().connection_made(transport) self.controller.add_session(self) def connection_lost(self, exc): '''Handle client disconnection.''' super().connection_lost(exc) msg = '' if self.pause: msg += ' whilst paused' if self.controller.is_deprioritized(self): msg += ' whilst deprioritized' 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.log_info(msg) self.controller.remove_session(self) def using_bandwidth(self, amount): now = time.time() # Reduce the recorded usage in proportion to the elapsed time elapsed = now - self.bw_time self.bandwidth_start = now refund = int(elapsed / self.bw_interval * self.bw_limit) refund = min(refund, self.bw_used) self.bw_used += amount - refund 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_height = False self.notified_height = None self.max_send = self.env.max_send self.max_subs = self.env.max_session_subs self.hashX_subs = {} self.mempool_statuses = {} self.chunk_indices = [] self.electrumx_handlers = { 'blockchain.address.subscribe': self.address_subscribe, 'blockchain.block.get_chunk': self.block_get_chunk, 'blockchain.headers.subscribe': self.headers_subscribe, 'blockchain.numblocks.subscribe': self.numblocks_subscribe, 'blockchain.script_hash.subscribe': self.script_hash_subscribe, 'blockchain.transaction.broadcast': self.transaction_broadcast, 'server.add_peer': self.add_peer, 'server.banner': self.banner, 'server.features': self.server_features, 'server.peers.subscribe': self.peers_subscribe, 'server.version': self.server_version, } def sub_count(self): return len(self.hashX_subs) async def notify(self, height, touched): '''Notify the client about changes in height and touched addresses. Cache is a shared cache for this update. ''' pairs = [] changed = [] matches = touched.intersection(self.hashX_subs) for hashX in matches: alias = self.hashX_subs[hashX] status = await self.address_status(hashX) changed.append((alias, status)) if height != self.notified_height: self.notified_height = height if self.subscribe_headers: args = (self.controller.electrum_header(height), ) pairs.append(('blockchain.headers.subscribe', args)) if self.subscribe_height: pairs.append(('blockchain.numblocks.subscribe', (height, ))) # Check mempool hashXs - the status is a function of the # confirmed state of other transactions for hashX in set(self.mempool_statuses).difference(matches): old_status = self.mempool_statuses[hashX] status = await self.address_status(hashX) if status != old_status: alias = self.hashX_subs[hashX] changed.append((alias, status)) for alias_status in changed: if len(alias_status[0]) == 64: method = 'blockchain.script_hash.subscribe' else: method = 'blockchain.address.subscribe' pairs.append((method, alias_status)) if pairs: self.send_notifications(pairs) if changed: es = '' if len(changed) == 1 else 'es' self.log_info('notified of {:,d} address{}' .format(len(changed), es)) def height(self): '''Return the current flushed database height.''' return self.bp.db_height def current_electrum_header(self): '''Used as response to a headers subscription request.''' return self.controller.electrum_header(self.height()) def headers_subscribe(self): '''Subscribe to get headers of new blocks.''' self.subscribe_headers = True return self.current_electrum_header() 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_info()) 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('your address subscription limit {:,d} reached' .format(self.max_subs)) # 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 script_hash_subscribe(self, script_hash): '''Subscribe to a script hash. script_hash: the SHA256 hash of the script to subscribe to''' hashX = self.controller.script_hash_to_hashX(script_hash) return await self.hashX_subscribe(hashX, script_hash) def server_features(self): '''Returns a dictionary of server features.''' return self.controller.peer_mgr.my_clearnet_peer().features 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) if self.client_version < (2, 8, 3): self.chunk_indices.append(index) self.chunk_indices = self.chunk_indices[-5:] # -2 allows backing up a single chunk but no more. if index <= max(self.chunk_indices[:-2], default=-1): msg = ('chunk indices not advancing (wrong network?): {}' .format(self.chunk_indices)) # use INVALID_REQUEST to trigger a disconnect raise RPCError(msg, JSONRPC.INVALID_REQUEST) return self.controller.get_chunk(index) def is_tor(self): '''Try to detect if the connection is to a tor hidden service we are running.''' proxy = self.controller.peer_mgr.proxy peer_info = self.peer_info() return peer_info and peer_info[0] == proxy.ip_addr 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 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.log_error('reading banner file {}: {}' .format(banner_file, e)) else: banner = await self.replaced_banner(banner) return banner 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: self.client = str(client_name)[:17] try: self.client_version = tuple(int(part) for part in self.client.split('.')) except Exception: pass if protocol_version is not None: self.protocol_version = protocol_version return version.VERSION async def transaction_broadcast(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: tx_hash = await self.daemon.sendrawtransaction([raw_tx]) self.txs_sent += 1 self.log_info('sent tx: {}'.format(tx_hash)) self.controller.sent_tx(tx_hash) return tx_hash except DaemonError as e: error = e.args[0] message = error['message'] self.log_info('sendrawtransaction: {}'.format(message), throttle=True) if 'non-mandatory-script-verify-flag' in message: return ( 'Your client produced a transaction that is not accepted ' 'by the network any more. Please upgrade to Electrum ' '2.5.1 or newer.' ) return ( 'The transaction was rejected by network rules. ({})\n[{}]' .format(message, raw_tx) ) def request_handler(self, method): '''Return the async handler for the given request method.''' handler = self.electrumx_handlers.get(method) if not handler: handler = self.controller.electrumx_handlers.get(method) return handler class LocalRPC(SessionBase): '''A local TCP RPC server session.''' def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.client = 'RPC' self.max_send = 0 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.electrumx_handlers['masternode.announce.broadcast'] = self.masternode_announce_broadcast self.electrumx_handlers['masternode.subscribe'] = self.masternode_subscribe self.subscribe_mns = False self.mns = set() async def notify(self, height, touched): '''Notify the client about changes in masternode list.''' await super().notify(height, touched) if self.subscribe_mns: for masternode in self.mns: status = await self.daemon.masternode_list(['status', masternode]) payload = { 'id': None, 'method': 'masternode.subscribe', 'params': [masternode], 'result': status.get(masternode), } self.send_binary(self.encode_payload(payload)) # Masternode command handlers async def masternode_announce_broadcast(self, signmnb): '''Pass through the parameters to the daemon. An ugly API: current Electrum clients only pass the masternode broadcast message 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: mnb_info = await self.daemon.masternode_broadcast(['relay',signmnb]) return mnb_info except DaemonError as e: error = e.args[0] message = error['message'] self.log_info('masternode_broadcast: {}'.format(message)) return ( 'The masternode broadcast was rejected. ({})\n[{}]' .format(message, signmnb) ) 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) self.subscribe_mns = True return result.get(vin)