# Copyright (c) 2016, Neil Booth # # All rights reserved. # # See the file "LICENCE" for information about the copyright # and warranty status of this software. '''Class for handling environment configuration and defaults.''' import resource from collections import namedtuple from ipaddress import ip_address from os import environ from lib.coins import Coin from lib.util import LoggedClass NetIdentity = namedtuple('NetIdentity', 'host tcp_port ssl_port nick_suffix') class Env(LoggedClass): '''Wraps environment configuration.''' class Error(Exception): pass def __init__(self): super().__init__() self.obsolete(['UTXO_MB', 'HIST_MB', 'NETWORK']) coin_name = self.default('COIN', 'Bitcoin') network = self.default('NET', 'mainnet') self.coin = Coin.lookup_coin_class(coin_name, network) self.db_dir = self.required('DB_DIRECTORY') self.cache_MB = self.integer('CACHE_MB', 1200) self.host = self.default('HOST', 'localhost') self.reorg_limit = self.integer('REORG_LIMIT', self.coin.REORG_LIMIT) self.daemon_url = self.required('DAEMON_URL') # Server stuff self.tcp_port = self.integer('TCP_PORT', None) self.ssl_port = self.integer('SSL_PORT', None) if self.ssl_port: self.ssl_certfile = self.required('SSL_CERTFILE') self.ssl_keyfile = self.required('SSL_KEYFILE') self.rpc_port = self.integer('RPC_PORT', 8000) self.max_subscriptions = self.integer('MAX_SUBSCRIPTIONS', 10000) self.banner_file = self.default('BANNER_FILE', None) self.tor_banner_file = self.default('TOR_BANNER_FILE', self.banner_file) self.anon_logs = self.default('ANON_LOGS', False) self.log_sessions = self.integer('LOG_SESSIONS', 3600) # Peer discovery self.peer_discovery = bool(self.default('PEER_DISCOVERY', True)) self.peer_announce = bool(self.default('PEER_ANNOUNCE', True)) self.force_proxy = bool(self.default('FORCE_PROXY', False)) self.tor_proxy_host = self.default('TOR_PROXY_HOST', 'localhost') self.tor_proxy_port = self.integer('TOR_PROXY_PORT', None) # The electrum client takes the empty string as unspecified self.donation_address = self.default('DONATION_ADDRESS', '') self.db_engine = self.default('DB_ENGINE', 'leveldb') # Server limits to help prevent DoS self.max_send = self.integer('MAX_SEND', 1000000) self.max_subs = self.integer('MAX_SUBS', 250000) self.max_sessions = self.sane_max_sessions() self.max_session_subs = self.integer('MAX_SESSION_SUBS', 50000) self.bandwidth_limit = self.integer('BANDWIDTH_LIMIT', 2000000) self.session_timeout = self.integer('SESSION_TIMEOUT', 600) # IRC self.irc = self.default('IRC', False) self.irc_nick = self.default('IRC_NICK', None) # Identities clearnet_identity = self.clearnet_identity() tor_identity = self.tor_identity(clearnet_identity) self.identities = [identity for identity in (clearnet_identity, tor_identity) if identity is not None] def default(self, envvar, default): return environ.get(envvar, default) def required(self, envvar): value = environ.get(envvar) if value is None: raise self.Error('required envvar {} not set'.format(envvar)) return value def integer(self, envvar, default): value = environ.get(envvar) if value is None: return default try: return int(value) except Exception: raise self.Error('cannot convert envvar {} value {} to an integer' .format(envvar, value)) def sane_max_sessions(self): '''Return the maximum number of sessions to permit. Normally this is MAX_SESSIONS. However, to prevent open file exhaustion, ajdust downwards if running with a small open file rlimit.''' env_value = self.integer('MAX_SESSIONS', 1000) nofile_limit = resource.getrlimit(resource.RLIMIT_NOFILE)[0] # We give the DB 250 files; allow ElectrumX 100 for itself value = max(0, min(env_value, nofile_limit - 350)) if value < env_value: self.log_warning('lowered maximum seessions from {:,d} to {:,d} ' 'because your open file limit is {:,d}' .format(env_value, value, nofile_limit)) return value def obsolete(self, envvars): bad = [envvar for envvar in envvars if environ.get(envvar)] if bad: raise self.Error('remove obsolete environment variables {}' .format(bad)) def clearnet_identity(self): host = self.default('REPORT_HOST', None) if host is None: return None try: ip = ip_address(host) except ValueError: bad = host.lower().strip() in ('', 'localhost') else: bad = (ip.is_multicast or ip.is_unspecified or (ip.is_private and (self.irc or self.peer_announce))) if bad: raise self.Error('"{}" is not a valid REPORT_HOST'.format(host)) tcp_port = self.integer('REPORT_TCP_PORT', self.tcp_port) or None ssl_port = self.integer('REPORT_SSL_PORT', self.ssl_port) or None if tcp_port == ssl_port: raise self.Error('REPORT_TCP_PORT and REPORT_SSL_PORT ' 'both resolve to {}'.format(tcp_port)) return NetIdentity( host, tcp_port, ssl_port, '' ) def tor_identity(self, clearnet): host = self.default('REPORT_HOST_TOR', None) if host is None: return None if not host.endswith('.onion'): raise self.Error('tor host "{}" must end with ".onion"' .format(host)) def port(port_kind): '''Returns the clearnet identity port, if any and not zero, otherwise the listening port.''' result = 0 if clearnet: result = getattr(clearnet, port_kind) return result or getattr(self, port_kind) tcp_port = self.integer('REPORT_TCP_PORT_TOR', port('tcp_port')) or None ssl_port = self.integer('REPORT_SSL_PORT_TOR', port('ssl_port')) or None if tcp_port == ssl_port: raise self.Error('REPORT_TCP_PORT_TOR and REPORT_SSL_PORT_TOR ' 'both resolve to {}'.format(tcp_port)) return NetIdentity( host, tcp_port, ssl_port, '_tor', )