#!/usr/bin/python # Usage: scripts/maint/updateFallbackDirs.py > src/or/fallback_dirs.inc # # This script should be run from a stable, reliable network connection, # with no other network activity (and not over tor). # If this is not possible, please disable: # PERFORM_IPV4_DIRPORT_CHECKS and PERFORM_IPV6_DIRPORT_CHECKS # # Needs dateutil (and potentially other python packages) # Needs stem available in your PYTHONPATH, or just ln -s ../stem/stem . # Optionally uses ipaddress (python 3 builtin) or py2-ipaddress (package) # for netblock analysis, in PYTHONPATH, or just # ln -s ../py2-ipaddress-3.4.1/ipaddress.py . # # Then read the logs to make sure the fallbacks aren't dominated by a single # netblock or port # Script by weasel, April 2015 # Portions by gsathya & karsten, 2013 # https://trac.torproject.org/projects/tor/attachment/ticket/8374/dir_list.2.py # Modifications by teor, 2015 import StringIO import string import re import datetime import gzip import os.path import json import math import sys import urllib import urllib2 import hashlib import dateutil.parser # bson_lazy provides bson #from bson import json_util import copy from stem.descriptor.remote import DescriptorDownloader import logging # INFO tells you why each relay was included or excluded # WARN tells you about potential misconfigurations and relay detail changes logging.basicConfig(level=logging.WARNING) logging.root.name = '' # INFO tells you about each consensus download attempt logging.getLogger('stem').setLevel(logging.WARNING) HAVE_IPADDRESS = False try: # python 3 builtin, or install package py2-ipaddress # there are several ipaddress implementations for python 2 # with slightly different semantics with str typed text # fortunately, all our IP addresses are in unicode import ipaddress HAVE_IPADDRESS = True except ImportError: # if this happens, we avoid doing netblock analysis logging.warning('Unable to import ipaddress, please install py2-ipaddress.' + ' A fallback list will be created, but optional netblock' + ' analysis will not be performed.') ## Top-Level Configuration # Output all candidate fallbacks, or only output selected fallbacks? OUTPUT_CANDIDATES = False # Perform DirPort checks over IPv4? # Change this to False if IPv4 doesn't work for you, or if you don't want to # download a consensus for each fallback # Don't check ~1000 candidates when OUTPUT_CANDIDATES is True PERFORM_IPV4_DIRPORT_CHECKS = False if OUTPUT_CANDIDATES else True # Perform DirPort checks over IPv6? # If you know IPv6 works for you, set this to True # This will exclude IPv6 relays without an IPv6 DirPort configured # So it's best left at False until #18394 is implemented # Don't check ~1000 candidates when OUTPUT_CANDIDATES is True PERFORM_IPV6_DIRPORT_CHECKS = False if OUTPUT_CANDIDATES else False # Output fallback name, flags, bandwidth, and ContactInfo in a C comment? OUTPUT_COMMENTS = True if OUTPUT_CANDIDATES else False # Output matching ContactInfo in fallbacks list or the blacklist? # Useful if you're trying to contact operators CONTACT_COUNT = True if OUTPUT_CANDIDATES else False CONTACT_BLACKLIST_COUNT = True if OUTPUT_CANDIDATES else False # How the list should be sorted: # fingerprint: is useful for stable diffs of fallback lists # measured_bandwidth: is useful when pruning the list based on bandwidth # contact: is useful for contacting operators once the list has been pruned OUTPUT_SORT_FIELD = 'contact' if OUTPUT_CANDIDATES else 'fingerprint' ## OnionOO Settings ONIONOO = 'https://onionoo.torproject.org/' #ONIONOO = 'https://onionoo.thecthulhu.com/' # Don't bother going out to the Internet, just use the files available locally, # even if they're very old LOCAL_FILES_ONLY = False ## Whitelist / Blacklist Filter Settings # The whitelist contains entries that are included if all attributes match # (IPv4, dirport, orport, id, and optionally IPv6 and IPv6 orport) # The blacklist contains (partial) entries that are excluded if any # sufficiently specific group of attributes matches: # IPv4 & DirPort # IPv4 & ORPort # ID # IPv6 & DirPort # IPv6 & IPv6 ORPort # If neither port is included in the blacklist, the entire IP address is # blacklisted. # What happens to entries in neither list? # When True, they are included, when False, they are excluded INCLUDE_UNLISTED_ENTRIES = True if OUTPUT_CANDIDATES else False # If an entry is in both lists, what happens? # When True, it is excluded, when False, it is included BLACKLIST_EXCLUDES_WHITELIST_ENTRIES = True WHITELIST_FILE_NAME = 'scripts/maint/fallback.whitelist' BLACKLIST_FILE_NAME = 'scripts/maint/fallback.blacklist' # The number of bytes we'll read from a filter file before giving up MAX_LIST_FILE_SIZE = 1024 * 1024 ## Eligibility Settings # Reduced due to a bug in tor where a relay submits a 0 DirPort when restarted # This causes OnionOO to (correctly) reset its stability timer # This issue will be fixed in 0.2.7.7 and 0.2.8.2 # Until then, the CUTOFFs below ensure a decent level of stability. ADDRESS_AND_PORT_STABLE_DAYS = 7 # What time-weighted-fraction of these flags must FallbackDirs # Equal or Exceed? CUTOFF_RUNNING = .95 CUTOFF_V2DIR = .95 CUTOFF_GUARD = .95 # What time-weighted-fraction of these flags must FallbackDirs # Equal or Fall Under? # .00 means no bad exits PERMITTED_BADEXIT = .00 # older entries' weights are adjusted with ALPHA^(age in days) AGE_ALPHA = 0.99 # this factor is used to scale OnionOO entries to [0,1] ONIONOO_SCALE_ONE = 999. ## Fallback Count Limits # The target for these parameters is 20% of the guards in the network # This is around 200 as of October 2015 _FB_POG = 0.2 FALLBACK_PROPORTION_OF_GUARDS = None if OUTPUT_CANDIDATES else _FB_POG # Limit the number of fallbacks (eliminating lowest by advertised bandwidth) MAX_FALLBACK_COUNT = None if OUTPUT_CANDIDATES else 200 # Emit a C #error if the number of fallbacks is more than 10% below MAX MIN_FALLBACK_COUNT = 0 if OUTPUT_CANDIDATES else MAX_FALLBACK_COUNT*0.9 ## Fallback Bandwidth Requirements # Any fallback with the Exit flag has its bandwidth multipled by this fraction # to make sure we aren't further overloading exits # (Set to 1.0, because we asked that only lightly loaded exits opt-in, # and the extra load really isn't that much for large relays.) EXIT_BANDWIDTH_FRACTION = 1.0 # If a single fallback's bandwidth is too low, it's pointless adding it # We expect fallbacks to handle an extra 30 kilobytes per second of traffic # Make sure they can support a hundred times the expected extra load # (Use 102.4 to make it come out nicely in MByte/s) # We convert this to a consensus weight before applying the filter, # because all the bandwidth amounts are specified by the relay MIN_BANDWIDTH = 102.4 * 30.0 * 1024.0 # Clients will time out after 30 seconds trying to download a consensus # So allow fallback directories half that to deliver a consensus # The exact download times might change based on the network connection # running this script, but only by a few seconds # There is also about a second of python overhead CONSENSUS_DOWNLOAD_SPEED_MAX = 15.0 # If the relay fails a consensus check, retry the download # This avoids delisting a relay due to transient network conditions CONSENSUS_DOWNLOAD_RETRY = True ## Fallback Weights for Client Selection # All fallback weights are equal, and set to the value below # Authorities are weighted 1.0 by default # Clients use these weights to select fallbacks and authorities at random # If there are 100 fallbacks and 9 authorities: # - each fallback is chosen with probability 10.0/(10.0*100 + 1.0*9) ~= 0.99% # - each authority is chosen with probability 1.0/(10.0*100 + 1.0*9) ~= 0.09% # A client choosing a bootstrap directory server will choose a fallback for # 10.0/(10.0*100 + 1.0*9) * 100 = 99.1% of attempts, and an authority for # 1.0/(10.0*100 + 1.0*9) * 9 = 0.9% of attempts. # (This disregards the bootstrap schedules, where clients start by choosing # from fallbacks & authoritites, then later choose from only authorities.) FALLBACK_OUTPUT_WEIGHT = 10.0 ## Parsing Functions def parse_ts(t): return datetime.datetime.strptime(t, "%Y-%m-%d %H:%M:%S") def remove_bad_chars(raw_string, bad_char_list): # Remove each character in the bad_char_list cleansed_string = raw_string for c in bad_char_list: cleansed_string = cleansed_string.replace(c, '') return cleansed_string def cleanse_unprintable(raw_string): # Remove all unprintable characters cleansed_string = '' for c in raw_string: if c in string.printable: cleansed_string += c return cleansed_string def cleanse_whitespace(raw_string): # Replace all whitespace characters with a space cleansed_string = raw_string for c in string.whitespace: cleansed_string = cleansed_string.replace(c, ' ') return cleansed_string def cleanse_c_multiline_comment(raw_string): cleansed_string = raw_string # Embedded newlines should be removed by tor/onionoo, but let's be paranoid cleansed_string = cleanse_whitespace(cleansed_string) # ContactInfo and Version can be arbitrary binary data cleansed_string = cleanse_unprintable(cleansed_string) # Prevent a malicious / unanticipated string from breaking out # of a C-style multiline comment # This removes '/*' and '*/' and '//' bad_char_list = '*/' # Prevent a malicious string from using C nulls bad_char_list += '\0' # Be safer by removing bad characters entirely cleansed_string = remove_bad_chars(cleansed_string, bad_char_list) # Some compilers may further process the content of comments # There isn't much we can do to cover every possible case # But comment-based directives are typically only advisory return cleansed_string def cleanse_c_string(raw_string): cleansed_string = raw_string # Embedded newlines should be removed by tor/onionoo, but let's be paranoid cleansed_string = cleanse_whitespace(cleansed_string) # ContactInfo and Version can be arbitrary binary data cleansed_string = cleanse_unprintable(cleansed_string) # Prevent a malicious address/fingerprint string from breaking out # of a C-style string bad_char_list = '"' # Prevent a malicious string from using escapes bad_char_list += '\\' # Prevent a malicious string from using C nulls bad_char_list += '\0' # Be safer by removing bad characters entirely cleansed_string = remove_bad_chars(cleansed_string, bad_char_list) # Some compilers may further process the content of strings # There isn't much we can do to cover every possible case # But this typically only results in changes to the string data return cleansed_string ## OnionOO Source Functions # a dictionary of source metadata for each onionoo query we've made fetch_source = {} # register source metadata for 'what' # assumes we only retrieve one document for each 'what' def register_fetch_source(what, url, relays_published, version): fetch_source[what] = {} fetch_source[what]['url'] = url fetch_source[what]['relays_published'] = relays_published fetch_source[what]['version'] = version # list each registered source's 'what' def fetch_source_list(): return sorted(fetch_source.keys()) # given 'what', provide a multiline C comment describing the source def describe_fetch_source(what): desc = '/*' desc += '\n' desc += 'Onionoo Source: ' desc += cleanse_c_multiline_comment(what) desc += ' Date: ' desc += cleanse_c_multiline_comment(fetch_source[what]['relays_published']) desc += ' Version: ' desc += cleanse_c_multiline_comment(fetch_source[what]['version']) desc += '\n' desc += 'URL: ' desc += cleanse_c_multiline_comment(fetch_source[what]['url']) desc += '\n' desc += '*/' return desc ## File Processing Functions def write_to_file(str, file_name, max_len): try: with open(file_name, 'w') as f: f.write(str[0:max_len]) except EnvironmentError, error: logging.error('Writing file %s failed: %d: %s'% (file_name, error.errno, error.strerror) ) def read_from_file(file_name, max_len): try: if os.path.isfile(file_name): with open(file_name, 'r') as f: return f.read(max_len) except EnvironmentError, error: logging.info('Loading file %s failed: %d: %s'% (file_name, error.errno, error.strerror) ) return None def load_possibly_compressed_response_json(response): if response.info().get('Content-Encoding') == 'gzip': buf = StringIO.StringIO( response.read() ) f = gzip.GzipFile(fileobj=buf) return json.load(f) else: return json.load(response) def load_json_from_file(json_file_name): # An exception here may be resolved by deleting the .last_modified # and .json files, and re-running the script try: with open(json_file_name, 'r') as f: return json.load(f) except EnvironmentError, error: raise Exception('Reading not-modified json file %s failed: %d: %s'% (json_file_name, error.errno, error.strerror) ) ## OnionOO Functions def datestr_to_datetime(datestr): # Parse datetimes like: Fri, 02 Oct 2015 13:34:14 GMT if datestr is not None: dt = dateutil.parser.parse(datestr) else: # Never modified - use start of epoch dt = datetime.datetime.utcfromtimestamp(0) # strip any timezone out (in case they're supported in future) dt = dt.replace(tzinfo=None) return dt def onionoo_fetch(what, **kwargs): params = kwargs params['type'] = 'relay' #params['limit'] = 10 params['first_seen_days'] = '%d-'%(ADDRESS_AND_PORT_STABLE_DAYS,) params['last_seen_days'] = '-7' params['flag'] = 'V2Dir' url = ONIONOO + what + '?' + urllib.urlencode(params) # Unfortunately, the URL is too long for some OS filenames, # but we still don't want to get files from different URLs mixed up base_file_name = what + '-' + hashlib.sha1(url).hexdigest() full_url_file_name = base_file_name + '.full_url' MAX_FULL_URL_LENGTH = 1024 last_modified_file_name = base_file_name + '.last_modified' MAX_LAST_MODIFIED_LENGTH = 64 json_file_name = base_file_name + '.json' if LOCAL_FILES_ONLY: # Read from the local file, don't write to anything response_json = load_json_from_file(json_file_name) else: # store the full URL to a file for debugging # no need to compare as long as you trust SHA-1 write_to_file(url, full_url_file_name, MAX_FULL_URL_LENGTH) request = urllib2.Request(url) request.add_header('Accept-encoding', 'gzip') # load the last modified date from the file, if it exists last_mod_date = read_from_file(last_modified_file_name, MAX_LAST_MODIFIED_LENGTH) if last_mod_date is not None: request.add_header('If-modified-since', last_mod_date) # Parse last modified date last_mod = datestr_to_datetime(last_mod_date) # Not Modified and still recent enough to be useful # Onionoo / Globe used to use 6 hours, but we can afford a day required_freshness = datetime.datetime.utcnow() # strip any timezone out (to match dateutil.parser) required_freshness = required_freshness.replace(tzinfo=None) required_freshness -= datetime.timedelta(hours=24) # Make the OnionOO request response_code = 0 try: response = urllib2.urlopen(request) response_code = response.getcode() except urllib2.HTTPError, error: response_code = error.code if response_code == 304: # not modified pass else: raise Exception("Could not get " + url + ": " + str(error.code) + ": " + error.reason) if response_code == 200: # OK last_mod = datestr_to_datetime(response.info().get('Last-Modified')) # Check for freshness if last_mod < required_freshness: if last_mod_date is not None: # This check sometimes fails transiently, retry the script if it does date_message = "Outdated data: last updated " + last_mod_date else: date_message = "No data: never downloaded " raise Exception(date_message + " from " + url) # Process the data if response_code == 200: # OK response_json = load_possibly_compressed_response_json(response) with open(json_file_name, 'w') as f: # use the most compact json representation to save space json.dump(response_json, f, separators=(',',':')) # store the last modified date in its own file if response.info().get('Last-modified') is not None: write_to_file(response.info().get('Last-Modified'), last_modified_file_name, MAX_LAST_MODIFIED_LENGTH) elif response_code == 304: # Not Modified response_json = load_json_from_file(json_file_name) else: # Unexpected HTTP response code not covered in the HTTPError above raise Exception("Unexpected HTTP response code to " + url + ": " + str(response_code)) register_fetch_source(what, url, response_json['relays_published'], response_json['version']) return response_json def fetch(what, **kwargs): #x = onionoo_fetch(what, **kwargs) # don't use sort_keys, as the order of or_addresses is significant #print json.dumps(x, indent=4, separators=(',', ': ')) #sys.exit(0) return onionoo_fetch(what, **kwargs) ## Fallback Candidate Class class Candidate(object): CUTOFF_ADDRESS_AND_PORT_STABLE = (datetime.datetime.utcnow() - datetime.timedelta(ADDRESS_AND_PORT_STABLE_DAYS)) def __init__(self, details): for f in ['fingerprint', 'nickname', 'last_changed_address_or_port', 'consensus_weight', 'or_addresses', 'dir_address']: if not f in details: raise Exception("Document has no %s field."%(f,)) if not 'contact' in details: details['contact'] = None if not 'flags' in details or details['flags'] is None: details['flags'] = [] if (not 'advertised_bandwidth' in details or details['advertised_bandwidth'] is None): # relays without advertised bandwdith have it calculated from their # consensus weight details['advertised_bandwidth'] = 0 if (not 'effective_family' in details or details['effective_family'] is None): details['effective_family'] = [] details['last_changed_address_or_port'] = parse_ts( details['last_changed_address_or_port']) self._data = details self._stable_sort_or_addresses() self._fpr = self._data['fingerprint'] self._running = self._guard = self._v2dir = 0. self._split_dirport() self._compute_orport() if self.orport is None: raise Exception("Failed to get an orport for %s."%(self._fpr,)) self._compute_ipv6addr() if not self.has_ipv6(): logging.debug("Failed to get an ipv6 address for %s."%(self._fpr,)) def _stable_sort_or_addresses(self): # replace self._data['or_addresses'] with a stable ordering, # sorting the secondary addresses in string order # leave the received order in self._data['or_addresses_raw'] self._data['or_addresses_raw'] = self._data['or_addresses'] or_address_primary = self._data['or_addresses'][:1] # subsequent entries in the or_addresses array are in an arbitrary order # so we stabilise the addresses by sorting them in string order or_addresses_secondaries_stable = sorted(self._data['or_addresses'][1:]) or_addresses_stable = or_address_primary + or_addresses_secondaries_stable self._data['or_addresses'] = or_addresses_stable def get_fingerprint(self): return self._fpr # is_valid_ipv[46]_address by gsathya, karsten, 2013 @staticmethod def is_valid_ipv4_address(address): if not isinstance(address, (str, unicode)): return False # check if there are four period separated values if address.count(".") != 3: return False # checks that each value in the octet are decimal values between 0-255 for entry in address.split("."): if not entry.isdigit() or int(entry) < 0 or int(entry) > 255: return False elif entry[0] == "0" and len(entry) > 1: return False # leading zeros, for instance in "1.2.3.001" return True @staticmethod def is_valid_ipv6_address(address): if not isinstance(address, (str, unicode)): return False # remove brackets address = address[1:-1] # addresses are made up of eight colon separated groups of four hex digits # with leading zeros being optional # https://en.wikipedia.org/wiki/IPv6#Address_format colon_count = address.count(":") if colon_count > 7: return False # too many groups elif colon_count != 7 and not "::" in address: return False # not enough groups and none are collapsed elif address.count("::") > 1 or ":::" in address: return False # multiple groupings of zeros can't be collapsed found_ipv4_on_previous_entry = False for entry in address.split(":"): # If an IPv6 address has an embedded IPv4 address, # it must be the last entry if found_ipv4_on_previous_entry: return False if not re.match("^[0-9a-fA-f]{0,4}$", entry): if not Candidate.is_valid_ipv4_address(entry): return False else: found_ipv4_on_previous_entry = True return True def _split_dirport(self): # Split the dir_address into dirip and dirport (self.dirip, _dirport) = self._data['dir_address'].split(':', 2) self.dirport = int(_dirport) def _compute_orport(self): # Choose the first ORPort that's on the same IPv4 address as the DirPort. # In rare circumstances, this might not be the primary ORPort address. # However, _stable_sort_or_addresses() ensures we choose the same one # every time, even if onionoo changes the order of the secondaries. self._split_dirport() self.orport = None for i in self._data['or_addresses']: if i != self._data['or_addresses'][0]: logging.debug('Secondary IPv4 Address Used for %s: %s'%(self._fpr, i)) (ipaddr, port) = i.rsplit(':', 1) if (ipaddr == self.dirip) and Candidate.is_valid_ipv4_address(ipaddr): self.orport = int(port) return def _compute_ipv6addr(self): # Choose the first IPv6 address that uses the same port as the ORPort # Or, choose the first IPv6 address in the list # _stable_sort_or_addresses() ensures we choose the same IPv6 address # every time, even if onionoo changes the order of the secondaries. self.ipv6addr = None self.ipv6orport = None # Choose the first IPv6 address that uses the same port as the ORPort for i in self._data['or_addresses']: (ipaddr, port) = i.rsplit(':', 1) if (port == self.orport) and Candidate.is_valid_ipv6_address(ipaddr): self.ipv6addr = ipaddr self.ipv6orport = int(port) return # Choose the first IPv6 address in the list for i in self._data['or_addresses']: (ipaddr, port) = i.rsplit(':', 1) if Candidate.is_valid_ipv6_address(ipaddr): self.ipv6addr = ipaddr self.ipv6orport = int(port) return @staticmethod def _extract_generic_history(history, which='unknown'): # given a tree like this: # { # "1_month": { # "count": 187, # "factor": 0.001001001001001001, # "first": "2015-02-27 06:00:00", # "interval": 14400, # "last": "2015-03-30 06:00:00", # "values": [ # 999, # 999 # ] # }, # "1_week": { # "count": 169, # "factor": 0.001001001001001001, # "first": "2015-03-23 07:30:00", # "interval": 3600, # "last": "2015-03-30 07:30:00", # "values": [ ...] # }, # "1_year": { # "count": 177, # "factor": 0.001001001001001001, # "first": "2014-04-11 00:00:00", # "interval": 172800, # "last": "2015-03-29 00:00:00", # "values": [ ...] # }, # "3_months": { # "count": 185, # "factor": 0.001001001001001001, # "first": "2014-12-28 06:00:00", # "interval": 43200, # "last": "2015-03-30 06:00:00", # "values": [ ...] # } # }, # extract exactly one piece of data per time interval, # using smaller intervals where available. # # returns list of (age, length, value) dictionaries. generic_history = [] periods = history.keys() periods.sort(key = lambda x: history[x]['interval']) now = datetime.datetime.utcnow() newest = now for p in periods: h = history[p] interval = datetime.timedelta(seconds = h['interval']) this_ts = parse_ts(h['last']) if (len(h['values']) != h['count']): logging.warning('Inconsistent value count in %s document for %s' %(p, which)) for v in reversed(h['values']): if (this_ts <= newest): agt1 = now - this_ts agt2 = interval agetmp1 = (agt1.microseconds + (agt1.seconds + agt1.days * 24 * 3600) * 10**6) / 10**6 agetmp2 = (agt2.microseconds + (agt2.seconds + agt2.days * 24 * 3600) * 10**6) / 10**6 generic_history.append( { 'age': agetmp1, 'length': agetmp2, 'value': v }) newest = this_ts this_ts -= interval if (this_ts + interval != parse_ts(h['first'])): logging.warning('Inconsistent time information in %s document for %s' %(p, which)) #print json.dumps(generic_history, sort_keys=True, # indent=4, separators=(',', ': ')) return generic_history @staticmethod def _avg_generic_history(generic_history): a = [] for i in generic_history: if i['age'] > (ADDRESS_AND_PORT_STABLE_DAYS * 24 * 3600): continue if (i['length'] is not None and i['age'] is not None and i['value'] is not None): w = i['length'] * math.pow(AGE_ALPHA, i['age']/(3600*24)) a.append( (i['value'] * w, w) ) sv = math.fsum(map(lambda x: x[0], a)) sw = math.fsum(map(lambda x: x[1], a)) if sw == 0.0: svw = 0.0 else: svw = sv/sw return svw def _add_generic_history(self, history): periods = r['read_history'].keys() periods.sort(key = lambda x: r['read_history'][x]['interval'] ) print periods def add_running_history(self, history): pass def add_uptime(self, uptime): logging.debug('Adding uptime %s.'%(self._fpr,)) # flags we care about: Running, V2Dir, Guard if not 'flags' in uptime: logging.debug('No flags in document for %s.'%(self._fpr,)) return for f in ['Running', 'Guard', 'V2Dir']: if not f in uptime['flags']: logging.debug('No %s in flags for %s.'%(f, self._fpr,)) return running = self._extract_generic_history(uptime['flags']['Running'], '%s-Running'%(self._fpr)) guard = self._extract_generic_history(uptime['flags']['Guard'], '%s-Guard'%(self._fpr)) v2dir = self._extract_generic_history(uptime['flags']['V2Dir'], '%s-V2Dir'%(self._fpr)) if 'BadExit' in uptime['flags']: badexit = self._extract_generic_history(uptime['flags']['BadExit'], '%s-BadExit'%(self._fpr)) self._running = self._avg_generic_history(running) / ONIONOO_SCALE_ONE self._guard = self._avg_generic_history(guard) / ONIONOO_SCALE_ONE self._v2dir = self._avg_generic_history(v2dir) / ONIONOO_SCALE_ONE self._badexit = None if 'BadExit' in uptime['flags']: self._badexit = self._avg_generic_history(badexit) / ONIONOO_SCALE_ONE def is_candidate(self): must_be_running_now = (PERFORM_IPV4_DIRPORT_CHECKS or PERFORM_IPV6_DIRPORT_CHECKS) if (must_be_running_now and not self.is_running()): logging.info('%s not a candidate: not running now, unable to check ' + 'DirPort consensus download', self._fpr) return False if (self._data['last_changed_address_or_port'] > self.CUTOFF_ADDRESS_AND_PORT_STABLE): logging.info('%s not a candidate: changed address/port recently (%s)', self._fpr, self._data['last_changed_address_or_port']) return False if self._running < CUTOFF_RUNNING: logging.info('%s not a candidate: running avg too low (%lf)', self._fpr, self._running) return False if self._v2dir < CUTOFF_V2DIR: logging.info('%s not a candidate: v2dir avg too low (%lf)', self._fpr, self._v2dir) return False if self._badexit is not None and self._badexit > PERMITTED_BADEXIT: logging.info('%s not a candidate: badexit avg too high (%lf)', self._fpr, self._badexit) return False # if the relay doesn't report a version, also exclude the relay if (not self._data.has_key('recommended_version') or not self._data['recommended_version']): logging.info('%s not a candidate: version not recommended', self._fpr) return False if self._guard < CUTOFF_GUARD: logging.info('%s not a candidate: guard avg too low (%lf)', self._fpr, self._guard) return False if (not self._data.has_key('consensus_weight') or self._data['consensus_weight'] < 1): logging.info('%s not a candidate: consensus weight invalid', self._fpr) return False return True def is_in_whitelist(self, relaylist): """ A fallback matches if each key in the whitelist line matches: ipv4 dirport orport id ipv6 address and port (if present) If the fallback has an ipv6 key, the whitelist line must also have it, and vice versa, otherwise they don't match. """ ipv6 = None if self.has_ipv6(): ipv6 = '%s:%d'%(self.ipv6addr, self.ipv6orport) for entry in relaylist: if entry['id'] != self._fpr: # can't log here unless we match an IP and port, because every relay's # fingerprint is compared to every entry's fingerprint if entry['ipv4'] == self.dirip and int(entry['orport']) == self.orport: logging.warning('%s excluded: has OR %s:%d changed fingerprint to ' + '%s?', entry['id'], self.dirip, self.orport, self._fpr) if self.has_ipv6() and entry.has_key('ipv6') and entry['ipv6'] == ipv6: logging.warning('%s excluded: has OR %s changed fingerprint to ' + '%s?', entry['id'], ipv6, self._fpr) continue if entry['ipv4'] != self.dirip: logging.warning('%s excluded: has it changed IPv4 from %s to %s?', self._fpr, entry['ipv4'], self.dirip) continue if int(entry['dirport']) != self.dirport: logging.warning('%s excluded: has it changed DirPort from %s:%d to ' + '%s:%d?', self._fpr, self.dirip, int(entry['dirport']), self.dirip, self.dirport) continue if int(entry['orport']) != self.orport: logging.warning('%s excluded: has it changed ORPort from %s:%d to ' + '%s:%d?', self._fpr, self.dirip, int(entry['orport']), self.dirip, self.orport) continue if entry.has_key('ipv6') and self.has_ipv6(): # if both entry and fallback have an ipv6 address, compare them if entry['ipv6'] != ipv6: logging.warning('%s excluded: has it changed IPv6 ORPort from %s ' + 'to %s?', self._fpr, entry['ipv6'], ipv6) continue # if the fallback has an IPv6 address but the whitelist entry # doesn't, or vice versa, the whitelist entry doesn't match elif entry.has_key('ipv6') and not self.has_ipv6(): logging.warning('%s excluded: has it lost its former IPv6 address %s?', self._fpr, entry['ipv6']) continue elif not entry.has_key('ipv6') and self.has_ipv6(): logging.warning('%s excluded: has it gained an IPv6 address %s?', self._fpr, ipv6) continue return True return False def is_in_blacklist(self, relaylist): """ A fallback matches a blacklist line if a sufficiently specific group of attributes matches: ipv4 & dirport ipv4 & orport id ipv6 & dirport ipv6 & ipv6 orport If the fallback and the blacklist line both have an ipv6 key, their values will be compared, otherwise, they will be ignored. If there is no dirport and no orport, the entry matches all relays on that ip. """ for entry in relaylist: for key in entry: value = entry[key] if key == 'id' and value == self._fpr: logging.info('%s is in the blacklist: fingerprint matches', self._fpr) return True if key == 'ipv4' and value == self.dirip: # if the dirport is present, check it too if entry.has_key('dirport'): if int(entry['dirport']) == self.dirport: logging.info('%s is in the blacklist: IPv4 (%s) and ' + 'DirPort (%d) match', self._fpr, self.dirip, self.dirport) return True # if the orport is present, check it too elif entry.has_key('orport'): if int(entry['orport']) == self.orport: logging.info('%s is in the blacklist: IPv4 (%s) and ' + 'ORPort (%d) match', self._fpr, self.dirip, self.orport) return True else: logging.info('%s is in the blacklist: IPv4 (%s) matches, and ' + 'entry has no DirPort or ORPort', self._fpr, self.dirip) return True ipv6 = None if self.has_ipv6(): ipv6 = '%s:%d'%(self.ipv6addr, self.ipv6orport) if (key == 'ipv6' and self.has_ipv6()): # if both entry and fallback have an ipv6 address, compare them, # otherwise, disregard ipv6 addresses if value == ipv6: # if the dirport is present, check it too if entry.has_key('dirport'): if int(entry['dirport']) == self.dirport: logging.info('%s is in the blacklist: IPv6 (%s) and ' + 'DirPort (%d) match', self._fpr, ipv6, self.dirport) return True # we've already checked the ORPort, it's part of entry['ipv6'] else: logging.info('%s is in the blacklist: IPv6 (%s) matches, and' + 'entry has no DirPort', self._fpr, ipv6) return True elif (key == 'ipv6' or self.has_ipv6()): # only log if the fingerprint matches but the IPv6 doesn't if entry.has_key('id') and entry['id'] == self._fpr: logging.info('%s skipping IPv6 blacklist comparison: relay ' + 'has%s IPv6%s, but entry has%s IPv6%s', self._fpr, '' if self.has_ipv6() else ' no', (' (' + ipv6 + ')') if self.has_ipv6() else '', '' if key == 'ipv6' else ' no', (' (' + value + ')') if key == 'ipv6' else '') logging.warning('Has %s %s IPv6 address %s?', self._fpr, 'gained an' if self.has_ipv6() else 'lost its former', ipv6 if self.has_ipv6() else value) return False def cw_to_bw_factor(self): # any relays with a missing or zero consensus weight are not candidates # any relays with a missing advertised bandwidth have it set to zero return self._data['advertised_bandwidth'] / self._data['consensus_weight'] # since advertised_bandwidth is reported by the relay, it can be gamed # to avoid this, use the median consensus weight to bandwidth factor to # estimate this relay's measured bandwidth, and make that the upper limit def measured_bandwidth(self, median_cw_to_bw_factor): cw_to_bw= median_cw_to_bw_factor # Reduce exit bandwidth to make sure we're not overloading them if self.is_exit(): cw_to_bw *= EXIT_BANDWIDTH_FRACTION measured_bandwidth = self._data['consensus_weight'] * cw_to_bw if self._data['advertised_bandwidth'] != 0: # limit advertised bandwidth (if available) to measured bandwidth return min(measured_bandwidth, self._data['advertised_bandwidth']) else: return measured_bandwidth def set_measured_bandwidth(self, median_cw_to_bw_factor): self._data['measured_bandwidth'] = self.measured_bandwidth( median_cw_to_bw_factor) def is_exit(self): return 'Exit' in self._data['flags'] def is_guard(self): return 'Guard' in self._data['flags'] def is_running(self): return 'Running' in self._data['flags'] # does this fallback have an IPv6 address and orport? def has_ipv6(self): return self.ipv6addr is not None and self.ipv6orport is not None # strip leading and trailing brackets from an IPv6 address # safe to use on non-bracketed IPv6 and on IPv4 addresses # also convert to unicode, and make None appear as '' @staticmethod def strip_ipv6_brackets(ip): if ip is None: return unicode('') if len(ip) < 2: return unicode(ip) if ip[0] == '[' and ip[-1] == ']': return unicode(ip[1:-1]) return unicode(ip) # are ip_a and ip_b in the same netblock? # mask_bits is the size of the netblock # takes both IPv4 and IPv6 addresses # the versions of ip_a and ip_b must be the same # the mask must be valid for the IP version @staticmethod def netblocks_equal(ip_a, ip_b, mask_bits): if ip_a is None or ip_b is None: return False ip_a = Candidate.strip_ipv6_brackets(ip_a) ip_b = Candidate.strip_ipv6_brackets(ip_b) a = ipaddress.ip_address(ip_a) b = ipaddress.ip_address(ip_b) if a.version != b.version: raise Exception('Mismatching IP versions in %s and %s'%(ip_a, ip_b)) if mask_bits > a.max_prefixlen: logging.error('Bad IP mask %d for %s and %s'%(mask_bits, ip_a, ip_b)) mask_bits = a.max_prefixlen if mask_bits < 0: logging.error('Bad IP mask %d for %s and %s'%(mask_bits, ip_a, ip_b)) mask_bits = 0 a_net = ipaddress.ip_network('%s/%d'%(ip_a, mask_bits), strict=False) return b in a_net # is this fallback's IPv4 address (dirip) in the same netblock as other's # IPv4 address? # mask_bits is the size of the netblock def ipv4_netblocks_equal(self, other, mask_bits): return Candidate.netblocks_equal(self.dirip, other.dirip, mask_bits) # is this fallback's IPv6 address (ipv6addr) in the same netblock as # other's IPv6 address? # Returns False if either fallback has no IPv6 address # mask_bits is the size of the netblock def ipv6_netblocks_equal(self, other, mask_bits): if not self.has_ipv6() or not other.has_ipv6(): return False return Candidate.netblocks_equal(self.ipv6addr, other.ipv6addr, mask_bits) # is this fallback's IPv4 DirPort the same as other's IPv4 DirPort? def dirport_equal(self, other): return self.dirport == other.dirport # is this fallback's IPv4 ORPort the same as other's IPv4 ORPort? def ipv4_orport_equal(self, other): return self.orport == other.orport # is this fallback's IPv6 ORPort the same as other's IPv6 ORPort? # Returns False if either fallback has no IPv6 address def ipv6_orport_equal(self, other): if not self.has_ipv6() or not other.has_ipv6(): return False return self.ipv6orport == other.ipv6orport # does this fallback have the same DirPort, IPv4 ORPort, or # IPv6 ORPort as other? # Ignores IPv6 ORPort if either fallback has no IPv6 address def port_equal(self, other): return (self.dirport_equal(other) or self.ipv4_orport_equal(other) or self.ipv6_orport_equal(other)) # return a list containing IPv4 ORPort, DirPort, and IPv6 ORPort (if present) def port_list(self): ports = [self.dirport, self.orport] if self.has_ipv6() and not self.ipv6orport in ports: ports.append(self.ipv6orport) return ports # does this fallback share a port with other, regardless of whether the # port types match? # For example, if self's IPv4 ORPort is 80 and other's DirPort is 80, # return True def port_shared(self, other): for p in self.port_list(): if p in other.port_list(): return True return False # report how long it takes to download a consensus from dirip:dirport @staticmethod def fallback_consensus_download_speed(dirip, dirport, nickname, max_time): download_failed = False downloader = DescriptorDownloader() start = datetime.datetime.utcnow() # some directory mirrors respond to requests in ways that hang python # sockets, which is why we log this line here logging.info('Initiating consensus download from %s (%s:%d).', nickname, dirip, dirport) # there appears to be about 1 second of overhead when comparing stem's # internal trace time and the elapsed time calculated here TIMEOUT_SLOP = 1.0 try: downloader.get_consensus(endpoints = [(dirip, dirport)], timeout = (max_time + TIMEOUT_SLOP), validate = True, retries = 0, fall_back_to_authority = False).run() except Exception, stem_error: logging.info('Unable to retrieve a consensus from %s: %s', nickname, stem_error) status = 'error: "%s"' % (stem_error) level = logging.WARNING download_failed = True elapsed = (datetime.datetime.utcnow() - start).total_seconds() if elapsed > max_time: status = 'too slow' level = logging.WARNING download_failed = True else: status = 'ok' level = logging.DEBUG logging.log(level, 'Consensus download: %0.1fs %s from %s (%s:%d), ' + 'max download time %0.1fs.', elapsed, status, nickname, dirip, dirport, max_time) return download_failed # does this fallback download the consensus fast enough? def check_fallback_download_consensus(self): # include the relay if we're not doing a check, or we can't check (IPv6) ipv4_failed = False ipv6_failed = False if PERFORM_IPV4_DIRPORT_CHECKS: ipv4_failed = Candidate.fallback_consensus_download_speed(self.dirip, self.dirport, self._data['nickname'], CONSENSUS_DOWNLOAD_SPEED_MAX) if self.has_ipv6() and PERFORM_IPV6_DIRPORT_CHECKS: # Clients assume the IPv6 DirPort is the same as the IPv4 DirPort ipv6_failed = Candidate.fallback_consensus_download_speed(self.ipv6addr, self.dirport, self._data['nickname'], CONSENSUS_DOWNLOAD_SPEED_MAX) return ((not ipv4_failed) and (not ipv6_failed)) # if this fallback has not passed a download check, try it again, # and record the result, available in get_fallback_download_consensus def try_fallback_download_consensus(self): if not self.get_fallback_download_consensus(): self._data['download_check'] = self.check_fallback_download_consensus() # did this fallback pass the download check? def get_fallback_download_consensus(self): # if we're not performing checks, return True if not PERFORM_IPV4_DIRPORT_CHECKS and not PERFORM_IPV6_DIRPORT_CHECKS: return True # if we are performing checks, but haven't done one, return False if not self._data.has_key('download_check'): return False return self._data['download_check'] # output an optional header comment and info for this fallback # try_fallback_download_consensus before calling this def fallbackdir_line(self, fallbacks, prefilter_fallbacks): s = '' if OUTPUT_COMMENTS: s += self.fallbackdir_comment(fallbacks, prefilter_fallbacks) # if the download speed is ok, output a C string # if it's not, but we OUTPUT_COMMENTS, output a commented-out C string if self.get_fallback_download_consensus() or OUTPUT_COMMENTS: s += self.fallbackdir_info(self.get_fallback_download_consensus()) return s # output a header comment for this fallback def fallbackdir_comment(self, fallbacks, prefilter_fallbacks): # /* # nickname # flags # adjusted bandwidth, consensus weight # [contact] # [identical contact counts] # */ # Multiline C comment s = '/*' s += '\n' s += cleanse_c_multiline_comment(self._data['nickname']) s += '\n' s += 'Flags: ' s += cleanse_c_multiline_comment(' '.join(sorted(self._data['flags']))) s += '\n' # this is an adjusted bandwidth, see calculate_measured_bandwidth() bandwidth = self._data['measured_bandwidth'] weight = self._data['consensus_weight'] s += 'Bandwidth: %.1f MByte/s, Consensus Weight: %d'%( bandwidth/(1024.0*1024.0), weight) s += '\n' if self._data['contact'] is not None: s += cleanse_c_multiline_comment(self._data['contact']) if CONTACT_COUNT or CONTACT_BLACKLIST_COUNT: fallback_count = len([f for f in fallbacks if f._data['contact'] == self._data['contact']]) if fallback_count > 1: s += '\n' s += '%d identical contacts listed' % (fallback_count) if CONTACT_BLACKLIST_COUNT: prefilter_count = len([f for f in prefilter_fallbacks if f._data['contact'] == self._data['contact']]) filter_count = prefilter_count - fallback_count if filter_count > 0: if fallback_count > 1: s += ' ' else: s += '\n' s += '%d blacklisted' % (filter_count) s += '\n' s += '*/' s += '\n' return s # output the fallback info C string for this fallback # this is the text that would go after FallbackDir in a torrc # if this relay failed the download test and we OUTPUT_COMMENTS, # comment-out the returned string def fallbackdir_info(self, dl_speed_ok): # "address:dirport orport=port id=fingerprint" # "[ipv6=addr:orport]" # "weight=FALLBACK_OUTPUT_WEIGHT", # # Do we want a C string, or a commented-out string? c_string = dl_speed_ok comment_string = not dl_speed_ok and OUTPUT_COMMENTS # If we don't want either kind of string, bail if not c_string and not comment_string: return '' s = '' # Comment out the fallback directory entry if it's too slow # See the debug output for which address and port is failing if comment_string: s += '/* Consensus download failed or was too slow:\n' # Multi-Line C string with trailing comma (part of a string list) # This makes it easier to diff the file, and remove IPv6 lines using grep # Integers don't need escaping s += '"%s orport=%d id=%s"'%( cleanse_c_string(self._data['dir_address']), self.orport, cleanse_c_string(self._fpr)) s += '\n' if self.has_ipv6(): s += '" ipv6=%s:%d"'%(cleanse_c_string(self.ipv6addr), self.ipv6orport) s += '\n' s += '" weight=%d",'%(FALLBACK_OUTPUT_WEIGHT) if comment_string: s += '\n' s += '*/' return s ## Fallback Candidate List Class class CandidateList(dict): def __init__(self): pass def _add_relay(self, details): if not 'dir_address' in details: return c = Candidate(details) self[ c.get_fingerprint() ] = c def _add_uptime(self, uptime): try: fpr = uptime['fingerprint'] except KeyError: raise Exception("Document has no fingerprint field.") try: c = self[fpr] except KeyError: logging.debug('Got unknown relay %s in uptime document.'%(fpr,)) return c.add_uptime(uptime) def _add_details(self): logging.debug('Loading details document.') d = fetch('details', fields=('fingerprint,nickname,contact,last_changed_address_or_port,' + 'consensus_weight,advertised_bandwidth,or_addresses,' + 'dir_address,recommended_version,flags,effective_family')) logging.debug('Loading details document done.') if not 'relays' in d: raise Exception("No relays found in document.") for r in d['relays']: self._add_relay(r) def _add_uptimes(self): logging.debug('Loading uptime document.') d = fetch('uptime') logging.debug('Loading uptime document done.') if not 'relays' in d: raise Exception("No relays found in document.") for r in d['relays']: self._add_uptime(r) def add_relays(self): self._add_details() self._add_uptimes() def count_guards(self): guard_count = 0 for fpr in self.keys(): if self[fpr].is_guard(): guard_count += 1 return guard_count # Find fallbacks that fit the uptime, stability, and flags criteria, # and make an array of them in self.fallbacks def compute_fallbacks(self): self.fallbacks = map(lambda x: self[x], filter(lambda x: self[x].is_candidate(), self.keys())) # sort fallbacks by their consensus weight to advertised bandwidth factor, # lowest to highest # used to find the median cw_to_bw_factor() def sort_fallbacks_by_cw_to_bw_factor(self): self.fallbacks.sort(key=lambda f: f.cw_to_bw_factor()) # sort fallbacks by their measured bandwidth, highest to lowest # calculate_measured_bandwidth before calling this # this is useful for reviewing candidates in priority order def sort_fallbacks_by_measured_bandwidth(self): self.fallbacks.sort(key=lambda f: f._data['measured_bandwidth'], reverse=True) # sort fallbacks by the data field data_field, lowest to highest def sort_fallbacks_by(self, data_field): self.fallbacks.sort(key=lambda f: f._data[data_field]) @staticmethod def load_relaylist(file_name): """ Read each line in the file, and parse it like a FallbackDir line: an IPv4 address and optional port: : which are parsed into dictionary entries: ipv4= dirport= followed by a series of key=value entries: orport= id= ipv6=: each line's key/value pairs are placed in a dictonary, (of string -> string key/value pairs), and these dictionaries are placed in an array. comments start with # and are ignored """ relaylist = [] file_data = read_from_file(file_name, MAX_LIST_FILE_SIZE) if file_data is None: return relaylist for line in file_data.split('\n'): relay_entry = {} # ignore comments line_comment_split = line.split('#') line = line_comment_split[0] # cleanup whitespace line = cleanse_whitespace(line) line = line.strip() if len(line) == 0: continue for item in line.split(' '): item = item.strip() if len(item) == 0: continue key_value_split = item.split('=') kvl = len(key_value_split) if kvl < 1 or kvl > 2: print '#error Bad %s item: %s, format is key=value.'%( file_name, item) if kvl == 1: # assume that entries without a key are the ipv4 address, # perhaps with a dirport ipv4_maybe_dirport = key_value_split[0] ipv4_maybe_dirport_split = ipv4_maybe_dirport.split(':') dirl = len(ipv4_maybe_dirport_split) if dirl < 1 or dirl > 2: print '#error Bad %s IPv4 item: %s, format is ipv4:port.'%( file_name, item) if dirl >= 1: relay_entry['ipv4'] = ipv4_maybe_dirport_split[0] if dirl == 2: relay_entry['dirport'] = ipv4_maybe_dirport_split[1] elif kvl == 2: relay_entry[key_value_split[0]] = key_value_split[1] relaylist.append(relay_entry) return relaylist # apply the fallback whitelist and blacklist def apply_filter_lists(self): excluded_count = 0 logging.debug('Applying whitelist and blacklist.') # parse the whitelist and blacklist whitelist = self.load_relaylist(WHITELIST_FILE_NAME) blacklist = self.load_relaylist(BLACKLIST_FILE_NAME) filtered_fallbacks = [] for f in self.fallbacks: in_whitelist = f.is_in_whitelist(whitelist) in_blacklist = f.is_in_blacklist(blacklist) if in_whitelist and in_blacklist: if BLACKLIST_EXCLUDES_WHITELIST_ENTRIES: # exclude excluded_count += 1 logging.warning('Excluding %s: in both blacklist and whitelist.', f._fpr) else: # include filtered_fallbacks.append(f) elif in_whitelist: # include filtered_fallbacks.append(f) elif in_blacklist: # exclude excluded_count += 1 logging.info('Excluding %s: in blacklist.', f._fpr) else: if INCLUDE_UNLISTED_ENTRIES: # include filtered_fallbacks.append(f) else: # exclude excluded_count += 1 logging.info('Excluding %s: in neither blacklist nor whitelist.', f._fpr) self.fallbacks = filtered_fallbacks return excluded_count @staticmethod def summarise_filters(initial_count, excluded_count): return '/* Whitelist & blacklist excluded %d of %d candidates. */'%( excluded_count, initial_count) # calculate each fallback's measured bandwidth based on the median # consensus weight to advertised bandwdith ratio def calculate_measured_bandwidth(self): self.sort_fallbacks_by_cw_to_bw_factor() median_fallback = self.fallback_median(True) if median_fallback is not None: median_cw_to_bw_factor = median_fallback.cw_to_bw_factor() else: # this will never be used, because there are no fallbacks median_cw_to_bw_factor = None for f in self.fallbacks: f.set_measured_bandwidth(median_cw_to_bw_factor) # remove relays with low measured bandwidth from the fallback list # calculate_measured_bandwidth for each relay before calling this def remove_low_bandwidth_relays(self): if MIN_BANDWIDTH is None: return above_min_bw_fallbacks = [] for f in self.fallbacks: if f._data['measured_bandwidth'] >= MIN_BANDWIDTH: above_min_bw_fallbacks.append(f) else: # the bandwidth we log here is limited by the relay's consensus weight # as well as its adverttised bandwidth. See set_measured_bandwidth # for details logging.info('%s not a candidate: bandwidth %.1fMByte/s too low, ' + 'must be at least %.1fMByte/s', f._fpr, f._data['measured_bandwidth']/(1024.0*1024.0), MIN_BANDWIDTH/(1024.0*1024.0)) self.fallbacks = above_min_bw_fallbacks # the minimum fallback in the list # call one of the sort_fallbacks_* functions before calling this def fallback_min(self): if len(self.fallbacks) > 0: return self.fallbacks[-1] else: return None # the median fallback in the list # call one of the sort_fallbacks_* functions before calling this def fallback_median(self, require_advertised_bandwidth): # use the low-median when there are an evan number of fallbacks, # for consistency with the bandwidth authorities if len(self.fallbacks) > 0: median_position = (len(self.fallbacks) - 1) / 2 if not require_advertised_bandwidth: return self.fallbacks[median_position] # if we need advertised_bandwidth but this relay doesn't have it, # move to a fallback with greater consensus weight until we find one while not self.fallbacks[median_position]._data['advertised_bandwidth']: median_position += 1 if median_position >= len(self.fallbacks): return None return self.fallbacks[median_position] else: return None # the maximum fallback in the list # call one of the sort_fallbacks_* functions before calling this def fallback_max(self): if len(self.fallbacks) > 0: return self.fallbacks[0] else: return None # does exclusion_list contain attribute? # if so, return False # if not, return True # if attribute is None or the empty string, always return True @staticmethod def allow(attribute, exclusion_list): if attribute is None or attribute == '': return True elif attribute in exclusion_list: return False else: return True # make sure there is only one fallback per IPv4 address, and per IPv6 address # there is only one IPv4 address on each fallback: the IPv4 DirPort address # (we choose the IPv4 ORPort which is on the same IPv4 as the DirPort) # there is at most one IPv6 address on each fallback: the IPv6 ORPort address # we try to match the IPv4 ORPort, but will use any IPv6 address if needed # (clients assume the IPv6 DirPort is the same as the IPv4 DirPort, but # typically only use the IPv6 ORPort) # if there is no IPv6 address, only the IPv4 address is checked # return the number of candidates we excluded def limit_fallbacks_same_ip(self): ip_limit_fallbacks = [] ip_list = [] for f in self.fallbacks: if (CandidateList.allow(f.dirip, ip_list) and CandidateList.allow(f.ipv6addr, ip_list)): ip_limit_fallbacks.append(f) ip_list.append(f.dirip) if f.has_ipv6(): ip_list.append(f.ipv6addr) elif not CandidateList.allow(f.dirip, ip_list): logging.info('Eliminated %s: already have fallback on IPv4 %s'%( f._fpr, f.dirip)) elif f.has_ipv6() and not CandidateList.allow(f.ipv6addr, ip_list): logging.info('Eliminated %s: already have fallback on IPv6 %s'%( f._fpr, f.ipv6addr)) original_count = len(self.fallbacks) self.fallbacks = ip_limit_fallbacks return original_count - len(self.fallbacks) # make sure there is only one fallback per ContactInfo # if there is no ContactInfo, allow the fallback # this check can be gamed by providing no ContactInfo, or by setting the # ContactInfo to match another fallback # However, given the likelihood that relays with the same ContactInfo will # go down at similar times, its usefulness outweighs the risk def limit_fallbacks_same_contact(self): contact_limit_fallbacks = [] contact_list = [] for f in self.fallbacks: if CandidateList.allow(f._data['contact'], contact_list): contact_limit_fallbacks.append(f) contact_list.append(f._data['contact']) else: logging.info(('Eliminated %s: already have fallback on ' + 'ContactInfo %s')%(f._fpr, f._data['contact'])) original_count = len(self.fallbacks) self.fallbacks = contact_limit_fallbacks return original_count - len(self.fallbacks) # make sure there is only one fallback per effective family # if there is no family, allow the fallback # this check can't be gamed, because we use effective family, which ensures # mutual family declarations # if any indirect families exist, the result depends on the order in which # fallbacks are sorted in the list def limit_fallbacks_same_family(self): family_limit_fallbacks = [] fingerprint_list = [] for f in self.fallbacks: if CandidateList.allow(f._fpr, fingerprint_list): family_limit_fallbacks.append(f) fingerprint_list.append(f._fpr) fingerprint_list.extend(f._data['effective_family']) else: # technically, we already have a fallback with this fallback in its # effective family logging.info('Eliminated %s: already have fallback in effective ' + 'family'%(f._fpr)) original_count = len(self.fallbacks) self.fallbacks = family_limit_fallbacks return original_count - len(self.fallbacks) # try a download check on each fallback candidate in order # stop after max_count successful downloads # but don't remove any candidates from the array def try_download_consensus_checks(self, max_count): dl_ok_count = 0 for f in self.fallbacks: f.try_fallback_download_consensus() if f.get_fallback_download_consensus(): # this fallback downloaded a consensus ok dl_ok_count += 1 if dl_ok_count >= max_count: # we have enough fallbacks return # put max_count successful candidates in the fallbacks array: # - perform download checks on each fallback candidate # - retry failed candidates if CONSENSUS_DOWNLOAD_RETRY is set # - eliminate failed candidates # - if there are more than max_count candidates, eliminate lowest bandwidth # - if there are fewer than max_count candidates, leave only successful # Return the number of fallbacks that failed the consensus check def perform_download_consensus_checks(self, max_count): self.sort_fallbacks_by_measured_bandwidth() self.try_download_consensus_checks(max_count) if CONSENSUS_DOWNLOAD_RETRY: # try unsuccessful candidates again # we could end up with more than max_count successful candidates here self.try_download_consensus_checks(max_count) # now we have at least max_count successful candidates, # or we've tried them all original_count = len(self.fallbacks) self.fallbacks = filter(lambda x: x.get_fallback_download_consensus(), self.fallbacks) # some of these failed the check, others skipped the check, # if we already had enough successful downloads failed_count = original_count - len(self.fallbacks) self.fallbacks = self.fallbacks[:max_count] return failed_count # return a string that describes a/b as a percentage @staticmethod def describe_percentage(a, b): if b != 0: return '%d/%d = %.0f%%'%(a, b, (a*100.0)/b) else: # technically, 0/0 is undefined, but 0.0% is a sensible result return '%d/%d = %.0f%%'%(a, b, 0.0) # return a dictionary of lists of fallbacks by IPv4 netblock # the dictionary is keyed by the fingerprint of an arbitrary fallback # in each netblock # mask_bits is the size of the netblock def fallbacks_by_ipv4_netblock(self, mask_bits): netblocks = {} for f in self.fallbacks: found_netblock = False for b in netblocks.keys(): # we found an existing netblock containing this fallback if f.ipv4_netblocks_equal(self[b], mask_bits): # add it to the list netblocks[b].append(f) found_netblock = True break # make a new netblock based on this fallback's fingerprint if not found_netblock: netblocks[f._fpr] = [f] return netblocks # return a dictionary of lists of fallbacks by IPv6 netblock # where mask_bits is the size of the netblock def fallbacks_by_ipv6_netblock(self, mask_bits): netblocks = {} for f in self.fallbacks: # skip fallbacks without IPv6 addresses if not f.has_ipv6(): continue found_netblock = False for b in netblocks.keys(): # we found an existing netblock containing this fallback if f.ipv6_netblocks_equal(self[b], mask_bits): # add it to the list netblocks[b].append(f) found_netblock = True break # make a new netblock based on this fallback's fingerprint if not found_netblock: netblocks[f._fpr] = [f] return netblocks # log a message about the proportion of fallbacks in each IPv4 netblock, # where mask_bits is the size of the netblock def describe_fallback_ipv4_netblock_mask(self, mask_bits): fallback_count = len(self.fallbacks) shared_netblock_fallback_count = 0 most_frequent_netblock = None netblocks = self.fallbacks_by_ipv4_netblock(mask_bits) for b in netblocks.keys(): if len(netblocks[b]) > 1: # how many fallbacks are in a netblock with other fallbacks? shared_netblock_fallback_count += len(netblocks[b]) # what's the netblock with the most fallbacks? if (most_frequent_netblock is None or len(netblocks[b]) > len(netblocks[most_frequent_netblock])): most_frequent_netblock = b logging.debug('Fallback IPv4 addresses in the same /%d:'%(mask_bits)) for f in netblocks[b]: logging.debug('%s - %s', f.dirip, f._fpr) if most_frequent_netblock is not None: logging.warning('There are %s fallbacks in the IPv4 /%d containing %s'%( CandidateList.describe_percentage( len(netblocks[most_frequent_netblock]), fallback_count), mask_bits, self[most_frequent_netblock].dirip)) if shared_netblock_fallback_count > 0: logging.warning(('%s of fallbacks are in an IPv4 /%d with other ' + 'fallbacks')%(CandidateList.describe_percentage( shared_netblock_fallback_count, fallback_count), mask_bits)) # log a message about the proportion of fallbacks in each IPv6 netblock, # where mask_bits is the size of the netblock def describe_fallback_ipv6_netblock_mask(self, mask_bits): fallback_count = len(self.fallbacks_with_ipv6()) shared_netblock_fallback_count = 0 most_frequent_netblock = None netblocks = self.fallbacks_by_ipv6_netblock(mask_bits) for b in netblocks.keys(): if len(netblocks[b]) > 1: # how many fallbacks are in a netblock with other fallbacks? shared_netblock_fallback_count += len(netblocks[b]) # what's the netblock with the most fallbacks? if (most_frequent_netblock is None or len(netblocks[b]) > len(netblocks[most_frequent_netblock])): most_frequent_netblock = b logging.debug('Fallback IPv6 addresses in the same /%d:'%(mask_bits)) for f in netblocks[b]: logging.debug('%s - %s', f.ipv6addr, f._fpr) if most_frequent_netblock is not None: logging.warning('There are %s fallbacks in the IPv6 /%d containing %s'%( CandidateList.describe_percentage( len(netblocks[most_frequent_netblock]), fallback_count), mask_bits, self[most_frequent_netblock].ipv6addr)) if shared_netblock_fallback_count > 0: logging.warning(('%s of fallbacks are in an IPv6 /%d with other ' + 'fallbacks')%(CandidateList.describe_percentage( shared_netblock_fallback_count, fallback_count), mask_bits)) # log a message about the proportion of fallbacks in each IPv4 /8, /16, # and /24 def describe_fallback_ipv4_netblocks(self): # this doesn't actually tell us anything useful #self.describe_fallback_ipv4_netblock_mask(8) self.describe_fallback_ipv4_netblock_mask(16) self.describe_fallback_ipv4_netblock_mask(24) # log a message about the proportion of fallbacks in each IPv6 /12 (RIR), # /23 (smaller RIR blocks), /32 (LIR), /48 (Customer), and /64 (Host) # https://www.iana.org/assignments/ipv6-unicast-address-assignments/ def describe_fallback_ipv6_netblocks(self): # these don't actually tell us anything useful #self.describe_fallback_ipv6_netblock_mask(12) #self.describe_fallback_ipv6_netblock_mask(23) self.describe_fallback_ipv6_netblock_mask(32) self.describe_fallback_ipv6_netblock_mask(48) self.describe_fallback_ipv6_netblock_mask(64) # log a message about the proportion of fallbacks in each IPv4 and IPv6 # netblock def describe_fallback_netblocks(self): self.describe_fallback_ipv4_netblocks() self.describe_fallback_ipv6_netblocks() # return a list of fallbacks which are on the IPv4 ORPort port def fallbacks_on_ipv4_orport(self, port): return filter(lambda x: x.orport == port, self.fallbacks) # return a list of fallbacks which are on the IPv6 ORPort port def fallbacks_on_ipv6_orport(self, port): return filter(lambda x: x.ipv6orport == port, self.fallbacks_with_ipv6()) # return a list of fallbacks which are on the DirPort port def fallbacks_on_dirport(self, port): return filter(lambda x: x.dirport == port, self.fallbacks) # log a message about the proportion of fallbacks on IPv4 ORPort port # and return that count def describe_fallback_ipv4_orport(self, port): port_count = len(self.fallbacks_on_ipv4_orport(port)) fallback_count = len(self.fallbacks) logging.warning('%s of fallbacks are on IPv4 ORPort %d'%( CandidateList.describe_percentage(port_count, fallback_count), port)) return port_count # log a message about the proportion of IPv6 fallbacks on IPv6 ORPort port # and return that count def describe_fallback_ipv6_orport(self, port): port_count = len(self.fallbacks_on_ipv6_orport(port)) fallback_count = len(self.fallbacks_with_ipv6()) logging.warning('%s of IPv6 fallbacks are on IPv6 ORPort %d'%( CandidateList.describe_percentage(port_count, fallback_count), port)) return port_count # log a message about the proportion of fallbacks on DirPort port # and return that count def describe_fallback_dirport(self, port): port_count = len(self.fallbacks_on_dirport(port)) fallback_count = len(self.fallbacks) logging.warning('%s of fallbacks are on DirPort %d'%( CandidateList.describe_percentage(port_count, fallback_count), port)) return port_count # log a message about the proportion of fallbacks on each dirport, # each IPv4 orport, and each IPv6 orport def describe_fallback_ports(self): fallback_count = len(self.fallbacks) ipv4_or_count = fallback_count ipv4_or_count -= self.describe_fallback_ipv4_orport(443) ipv4_or_count -= self.describe_fallback_ipv4_orport(9001) logging.warning('%s of fallbacks are on other IPv4 ORPorts'%( CandidateList.describe_percentage(ipv4_or_count, fallback_count))) ipv6_fallback_count = len(self.fallbacks_with_ipv6()) ipv6_or_count = ipv6_fallback_count ipv6_or_count -= self.describe_fallback_ipv6_orport(443) ipv6_or_count -= self.describe_fallback_ipv6_orport(9001) logging.warning('%s of IPv6 fallbacks are on other IPv6 ORPorts'%( CandidateList.describe_percentage(ipv6_or_count, ipv6_fallback_count))) dir_count = fallback_count dir_count -= self.describe_fallback_dirport(80) dir_count -= self.describe_fallback_dirport(9030) logging.warning('%s of fallbacks are on other DirPorts'%( CandidateList.describe_percentage(dir_count, fallback_count))) # return a list of fallbacks which have the Exit flag def fallbacks_with_exit(self): return filter(lambda x: x.is_exit(), self.fallbacks) # log a message about the proportion of fallbacks with an Exit flag def describe_fallback_exit_flag(self): exit_falback_count = len(self.fallbacks_with_exit()) fallback_count = len(self.fallbacks) logging.warning('%s of fallbacks have the Exit flag'%( CandidateList.describe_percentage(exit_falback_count, fallback_count))) # return a list of fallbacks which have an IPv6 address def fallbacks_with_ipv6(self): return filter(lambda x: x.has_ipv6(), self.fallbacks) # log a message about the proportion of fallbacks on IPv6 def describe_fallback_ip_family(self): ipv6_falback_count = len(self.fallbacks_with_ipv6()) fallback_count = len(self.fallbacks) logging.warning('%s of fallbacks are on IPv6'%( CandidateList.describe_percentage(ipv6_falback_count, fallback_count))) def summarise_fallbacks(self, eligible_count, operator_count, failed_count, guard_count, target_count): s = '' s += '/* To comment-out entries in this file, use C comments, and add *' s += ' to the start of each line. (stem finds fallback entries using "' s += ' at the start of a line.) */' s += '\n' # Report: # whether we checked consensus download times # the number of fallback directories (and limits/exclusions, if relevant) # min & max fallback bandwidths # #error if below minimum count if PERFORM_IPV4_DIRPORT_CHECKS or PERFORM_IPV6_DIRPORT_CHECKS: s += '/* Checked %s%s%s DirPorts served a consensus within %.1fs. */'%( 'IPv4' if PERFORM_IPV4_DIRPORT_CHECKS else '', ' and ' if (PERFORM_IPV4_DIRPORT_CHECKS and PERFORM_IPV6_DIRPORT_CHECKS) else '', 'IPv6' if PERFORM_IPV6_DIRPORT_CHECKS else '', CONSENSUS_DOWNLOAD_SPEED_MAX) else: s += '/* Did not check IPv4 or IPv6 DirPort consensus downloads. */' s += '\n' # Multiline C comment with #error if things go bad s += '/*' s += '\n' # Integers don't need escaping in C comments fallback_count = len(self.fallbacks) if FALLBACK_PROPORTION_OF_GUARDS is None: fallback_proportion = '' else: fallback_proportion = ', Target %d (%d * %.2f)'%(target_count, guard_count, FALLBACK_PROPORTION_OF_GUARDS) s += 'Final Count: %d (Eligible %d%s'%(fallback_count, eligible_count, fallback_proportion) if MAX_FALLBACK_COUNT is not None: s += ', Max %d'%(MAX_FALLBACK_COUNT) s += ')\n' if eligible_count != fallback_count: removed_count = eligible_count - fallback_count excess_to_target_or_max = (eligible_count - operator_count - failed_count - fallback_count) # some 'Failed' failed the check, others 'Skipped' the check, # if we already had enough successful downloads s += ('Excluded: %d (Same Operator %d, Failed/Skipped Download %d, ' + 'Excess %d)')%(removed_count, operator_count, failed_count, excess_to_target_or_max) s += '\n' min_fb = self.fallback_min() min_bw = min_fb._data['measured_bandwidth'] max_fb = self.fallback_max() max_bw = max_fb._data['measured_bandwidth'] s += 'Bandwidth Range: %.1f - %.1f MByte/s'%(min_bw/(1024.0*1024.0), max_bw/(1024.0*1024.0)) s += '\n' s += '*/' if fallback_count < MIN_FALLBACK_COUNT: # We must have a minimum number of fallbacks so they are always # reachable, and are in diverse locations s += '\n' s += '#error Fallback Count %d is too low. '%(fallback_count) s += 'Must be at least %d for diversity. '%(MIN_FALLBACK_COUNT) s += 'Try adding entries to the whitelist, ' s += 'or setting INCLUDE_UNLISTED_ENTRIES = True.' return s ## Main Function def list_fallbacks(): """ Fetches required onionoo documents and evaluates the fallback directory criteria for each of the relays """ logging.warning('Downloading and parsing Onionoo data. ' + 'This may take some time.') # find relays that could be fallbacks candidates = CandidateList() candidates.add_relays() # work out how many fallbacks we want guard_count = candidates.count_guards() if FALLBACK_PROPORTION_OF_GUARDS is None: target_count = guard_count else: target_count = int(guard_count * FALLBACK_PROPORTION_OF_GUARDS) # the maximum number of fallbacks is the least of: # - the target fallback count (FALLBACK_PROPORTION_OF_GUARDS * guard count) # - the maximum fallback count (MAX_FALLBACK_COUNT) if MAX_FALLBACK_COUNT is None: max_count = target_count else: max_count = min(target_count, MAX_FALLBACK_COUNT) candidates.compute_fallbacks() prefilter_fallbacks = copy.copy(candidates.fallbacks) # filter with the whitelist and blacklist # if a relay has changed IPv4 address or ports recently, it will be excluded # as ineligible before we call apply_filter_lists, and so there will be no # warning that the details have changed from those in the whitelist. # instead, there will be an info-level log during the eligibility check. initial_count = len(candidates.fallbacks) excluded_count = candidates.apply_filter_lists() print candidates.summarise_filters(initial_count, excluded_count) eligible_count = len(candidates.fallbacks) # calculate the measured bandwidth of each relay, # then remove low-bandwidth relays candidates.calculate_measured_bandwidth() candidates.remove_low_bandwidth_relays() # print the raw fallback list #for x in candidates.fallbacks: # print x.fallbackdir_line(True) # print json.dumps(candidates[x]._data, sort_keys=True, indent=4, # separators=(',', ': '), default=json_util.default) # impose mandatory conditions here, like one per contact, family, IP # in measured bandwidth order candidates.sort_fallbacks_by_measured_bandwidth() operator_count = 0 # only impose these limits on the final list - operators can nominate # multiple candidate fallbacks, and then we choose the best set if not OUTPUT_CANDIDATES: operator_count += candidates.limit_fallbacks_same_ip() operator_count += candidates.limit_fallbacks_same_contact() operator_count += candidates.limit_fallbacks_same_family() # check if each candidate can serve a consensus # there's a small risk we've eliminated relays from the same operator that # can serve a consensus, in favour of one that can't # but given it takes up to 15 seconds to check each consensus download, # the risk is worth it if PERFORM_IPV4_DIRPORT_CHECKS or PERFORM_IPV6_DIRPORT_CHECKS: logging.warning('Checking consensus download speeds. ' + 'This may take some time.') failed_count = candidates.perform_download_consensus_checks(max_count) # analyse and log interesting diversity metrics # like netblock, ports, exit, IPv4-only # (we can't easily analyse AS, and it's hard to accurately analyse country) candidates.describe_fallback_ip_family() # if we can't import the ipaddress module, we can't do netblock analysis if HAVE_IPADDRESS: candidates.describe_fallback_netblocks() candidates.describe_fallback_ports() candidates.describe_fallback_exit_flag() # output C comments summarising the fallback selection process if len(candidates.fallbacks) > 0: print candidates.summarise_fallbacks(eligible_count, operator_count, failed_count, guard_count, target_count) else: print '/* No Fallbacks met criteria */' # output C comments specifying the OnionOO data used to create the list for s in fetch_source_list(): print describe_fetch_source(s) # sort the list differently depending on why we've created it: # if we're outputting the final fallback list, sort by fingerprint # this makes diffs much more stable # otherwise, if we're trying to find a bandwidth cutoff, or we want to # contact operators in priority order, sort by bandwidth (not yet # implemented) # otherwise, if we're contacting operators, sort by contact candidates.sort_fallbacks_by(OUTPUT_SORT_FIELD) for x in candidates.fallbacks: print x.fallbackdir_line(candidates.fallbacks, prefilter_fallbacks) if __name__ == "__main__": list_fallbacks()