commit 417ebfa90429d3531e8a5310cf58dff4fc2ff158 Author: juga0 juga@riseup.net Date: Fri Feb 15 08:39:05 2019 +0000

new: relaylist: Store relays' consensus timestamps

for each relay and for the list of relays when fetching new network statuses. To count the number of times a relay was in a consensus and how many consensuses have been seen. In the test network router status entries don't have document attribute. Part of #28566 --- sbws/core/scanner.py | 6 +- sbws/globals.py | 10 +++ sbws/lib/relaylist.py | 178 ++++++++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 179 insertions(+), 15 deletions(-)

diff --git a/sbws/core/scanner.py b/sbws/core/scanner.py index 6842372..503f9cc 100644 --- a/sbws/core/scanner.py +++ b/sbws/core/scanner.py @@ -624,8 +624,10 @@ def run_speedtest(args, conf): # Call only once to initialize http_headers settings.init_http_headers(conf.get('scanner', 'nickname'), state['uuid'], str(controller.get_version())) - - rl = RelayList(args, conf, controller) + # To do not have to pass args and conf to RelayList, pass an extra + # argument with the data_period + measurements_period = conf.getint('general', 'data_period') + rl = RelayList(args, conf, controller, measurements_period) cb = CB(args, conf, controller, rl) rd = ResultDump(args, conf) rp = RelayPrioritizer(args, conf, rl, rd) diff --git a/sbws/globals.py b/sbws/globals.py index abd4791..015e857 100644 --- a/sbws/globals.py +++ b/sbws/globals.py @@ -84,6 +84,16 @@ MAX_BW_DIFF_PERC = 50 # Tor already accept lines of any size, but leaving the limit anyway. BW_LINE_SIZE = 1022

+# RelayList, ResultDump, v3bwfile +# For how many seconds in the past the relays and measurements data is keep/ +# considered valid. +# This is currently set by default in config.default.ini as ``date_period``, +# and used in ResultDump and v3bwfile. +# In a future refactor, constants in config.default.ini should be moved here, +# or calculated in settings, so that there's no need to pass the configuration +# to all the functions. +MEASUREMENTS_PERIOD = 5 * 24 * 60 * 60 + # Metadata to send in every requests, so that data servers can know which # scanners are using them. # In Requests these keys are case insensitive. diff --git a/sbws/lib/relaylist.py b/sbws/lib/relaylist.py index b296c06..bee0a14 100644 --- a/sbws/lib/relaylist.py +++ b/sbws/lib/relaylist.py @@ -1,16 +1,52 @@ +import copy +from datetime import datetime, timedelta + from stem.descriptor.router_status_entry import RouterStatusEntryV3 from stem.descriptor.server_descriptor import ServerDescriptor from stem import Flag, DescriptorUnavailable, ControllerError import random -import time import logging from threading import Lock

+from ..globals import MEASUREMENTS_PERIOD + log = logging.getLogger(__name__)

+def remove_old_consensus_timestamps( + consensus_timestamps, measurements_period=MEASUREMENTS_PERIOD): + """ + Remove the consensus timestamps that are older than period for which + the measurements are keep from a list of consensus_timestamps. + + :param list consensus_timestamps: + :param int measurements_period: + :returns list: a new list of ``consensus_timestamps`` + """ + oldest_date = datetime.utcnow() - timedelta(measurements_period) + new_consensus_timestamps = \ + [t for t in consensus_timestamps if t >= oldest_date] + return new_consensus_timestamps + + +def valid_after_from_network_statuses(network_statuses): + """Obtain the consensus Valid-After datetime from the ``document`` + attribute of a ``stem.descriptor.RouterStatusEntryV3``. + + :param list network_statuses: + returns datetime: + """ + for ns in network_statuses: + document = getattr(ns, 'document', None) + if document: + valid_after = getattr(document, 'valid_after', None) + if valid_after: + return valid_after + return datetime.utcnow().replace(microsecond=0) + + class Relay: - def __init__(self, fp, cont, ns=None, desc=None): + def __init__(self, fp, cont, ns=None, desc=None, timestamp=None): ''' Given a relay fingerprint, fetch all the information about a relay that sbws currently needs and store it in this class. Acts as an abstraction @@ -18,6 +54,9 @@ class Relay:

:param str fp: fingerprint of the relay. :param cont: active and valid stem Tor controller connection + + :param datatime timestamp: the timestamp of a consensus + (RouterStatusEntryV3) from which this relay has been obtained. ''' assert isinstance(fp, str) assert len(fp) == 40 @@ -38,6 +77,8 @@ class Relay: self._desc = cont.get_server_descriptor(fp, default=None) except (DescriptorUnavailable, ControllerError) as e: log.exception("Exception trying to get desc %s", e) + self._consensus_timestamps = [] + self._add_consensus_timestamp(timestamp)

def _from_desc(self, attr): if not self._desc: @@ -107,6 +148,63 @@ class Relay: return None return key.rstrip('=')

+ @property + def consensus_valid_after(self): + """Obtain the consensus Valid-After from the document of this relay + network status. + """ + network_status_document = self._from_ns('document') + if network_status_document: + return getattr(network_status_document, 'valid_after', None) + return None + + @property + def last_consensus_timestamp(self): + if len(self._consensus_timestamps) >= 1: + return self._consensus_timestamps[-1] + return None + + def _add_consensus_timestamp(self, timestamp=None): + """Add the consensus timestamp in which this relay is present. + """ + # It is possible to access to the relay's consensensus Valid-After + if self.consensus_valid_after is not None: + # The consensus timestamp list was initialized. + if self.last_consensus_timestamp is not None: + # Valid-After is more recent than the most recent stored + # consensus timestamp. + if self.consensus_valid_after > self.last_consensus_timestamp: + # Add Valid-After + self._consensus_timestamps.append( + self.consensus_valid_after + ) + # The consensus timestamp list was not initialized. + else: + # Add Valid-After + self._consensus_timestamps.append(self.consensus_valid_after) + # If there was already a list the timestamp arg is more recent than + # the most recent timestamp stored, + elif (self.last_consensus_timestamp is not None + and timestamp > self.last_consensus_timestamp): + # Add the arg timestamp. + self._consensus_timestamps.append(timestamp) + # In any other case + else: + # Add the current datetime + self._consensus_timestamps.append( + datetime.utcnow().replace(microsecond=0)) + + def _remove_old_consensus_timestamps( + self, measurements_period=MEASUREMENTS_PERIOD): + self._consensus_timestamps = \ + remove_old_consensus_timestamps( + copy.deepcopy(self._consensus_timestamps, measurements_period) + ) + + def update_consensus_timestamps(self, timestamp=None): + self._add_consensus_timestamp(timestamp) + self._remove_old_consensus_timestamps() + def can_exit_to_port(self, port): """ Returns True if the relay has an exit policy and the policy accepts @@ -129,16 +227,39 @@ class RelayList: transparently in the background. Provides useful interfaces for getting only relays of a certain type. ''' - REFRESH_INTERVAL = 300 # seconds

- def __init__(self, args, conf, controller): + def __init__(self, args, conf, controller, + measurements_period=MEASUREMENTS_PERIOD): self._controller = controller self.rng = random.SystemRandom() self._refresh_lock = Lock() + # To track all the consensus seen. + self._consensus_timestamps = [] + # Initialize so that there's no error trying to access to it. + # In future refactor, change to a dictionary, where the keys are + # the relays' fingerprint. + self._relays = [] + # The period of time for which the measurements are keep. + self._measurements_period = measurements_period self._refresh()

def _need_refresh(self): - return time.time() >= self._last_refresh + self.REFRESH_INTERVAL + # New consensuses happen every hour. + return datetime.utcnow() >= \ + self.last_consensus_timestamp + timedelta(seconds=60*60) + + @property + def last_consensus_timestamp(self): + """Returns the datetime when the last consensus was obtained.""" + if (getattr(self, "_consensus_timestamps") + and self._consensus_timestamps): + return self._consensus_timestamps[-1] + # If the object was not created from __init__, it won't have + # consensus_timestamps attribute or it might be empty. + # In this case force new update. + # Anytime more than 1h in the past will be old. + self._consensus_timestamps = [] + return datetime.utcnow() - timedelta(seconds=60*61)

@property def relays(self): @@ -197,19 +318,50 @@ class RelayList: def _relays_without_flag(self, flag): return [r for r in self.relays if flag not in r.flags]

+ def _remove_old_consensus_timestamps(self): + self._consensus_timestamps = remove_old_consensus_timestamps( + copy.deepcopy(self._consensus_timestamps), + self._measurements_period + ) + def _init_relays(self): + """Returns a new list of relays that are in the current consensus. + And update the consensus timestamp list with the current one. + + """ c = self._controller - try: - relays = [Relay(ns.fingerprint, c, ns=ns) - for ns in c.get_network_statuses()] - except ControllerError as e: - log.exception("Exception trying to init relays %s", e) - return [] - return relays + # This will get router statuses from this Tor cache, might not be + # updated with the network. + # Change to stem.descriptor.remote in future refactor. + network_statuses = c.get_network_statuses() + new_relays_dict = dict([(r.fingerprint, r) for r in network_statuses]) + + # Find the timestamp of the last consensus. + timestamp = valid_after_from_network_statuses(network_statuses) + self._consensus_timestamps.append(timestamp) + self._remove_old_consensus_timestamps() + # Update the relays that were in the previous consensus with the + # new timestamp + new_relays = [] + relays = copy.deepcopy(self._relays) + for r in relays: + if r.fingerprint in new_relays_dict.keys(): + r.update_consensus_timestamps(timestamp) + new_relays_dict.pop(r.fingerprint) + new_relays.append(r) + + # Add the relays that were not in the previous consensus + # If there was an relay in some older previous consensus, + # it won't get stored, so its previous consensuses are lost, + # but probably this is fine for now to don't make it more complicated. + for fp, ns in new_relays_dict.items(): + r = Relay(ns.fingerprint, c, ns=ns, timestamp=timestamp) + new_relays.append(r) + return new_relays

def _refresh(self): + # Set a new list of relays. self._relays = self._init_relays() - self._last_refresh = time.time()

def exits_not_bad_allowing_port(self, port): return [r for r in self.exits