commit 1a676f343a7a5a854106c9e90c8418d1f7b2c09e Author: Isis Lovecruft isis@torproject.org Date: Tue Apr 14 07:33:38 2015 +0000
Remove the idea of clusters. Clusters are just subhashrings. --- lib/bridgedb/Dist.py | 60 +++++++++++++++++++++++------------------------ lib/bridgedb/Filters.py | 2 +- 2 files changed, 30 insertions(+), 32 deletions(-)
diff --git a/lib/bridgedb/Dist.py b/lib/bridgedb/Dist.py index c9d82c1..58f0a2d 100644 --- a/lib/bridgedb/Dist.py +++ b/lib/bridgedb/Dist.py @@ -104,16 +104,15 @@ class IPBasedDistributor(Distributor): distributor. """
- def __init__(self, numberOfClusters, key, proxies=None, answerParameters=None): + def __init__(self, totalSubrings, key, proxies=None, answerParameters=None): """Create a Distributor that decides which bridges to distribute based upon the client's IP address and the current time.
- :param integer numberOfClusters: The number of clusters to group IP addresses - into. Note that if PROXY_LIST_FILES is set in bridgedb.conf, then - the actual number of clusters is one higher than ``numberOfClusters``, - because the set of known open proxies constitutes its own - category. - DOCDOC What exactly does a cluster *do*? + :param int totalSubrings: The number of subhashrings to group clients + into. Note that if ``PROXY_LIST_FILES`` is set in bridgedb.conf, + then the actual number of clusters is one higher than + ``totalSubrings``, because the set of all known open proxies is + given its own subhashring. :param bytes key: The master HMAC key for this distributor. All added bridges are HMACed with this key in order to place them into the hashrings. @@ -129,20 +128,20 @@ class IPBasedDistributor(Distributor): parameters, i.e. that an answer has "at least two obfsproxy bridges" or "at least one bridge on port 443", etc. """ + self.totalSubrings = totalSubrings self.answerParameters = answerParameters - self.numberOfClusters = numberOfClusters
if proxies: logging.info("Added known proxies to HTTPS distributor...") self.proxies = proxies - self.numberOfClusters += 1 - self.proxyCluster = self.numberOfClusters + self.totalSubrings += 1 + self.proxySubring = self.totalSubrings else: logging.warn("No known proxies were added to HTTPS distributor!") self.proxies = proxy.ProxySet() - self.proxyCluster = 0 + self.proxySubring = 0
- self.ringCacheSize = self.numberOfClusters * 3 + self.ringCacheSize = self.totalSubrings * 3
key2 = getHMAC(key, "Assign-Bridges-To-Rings") key3 = getHMAC(key, "Order-Areas-In-Rings") @@ -223,13 +222,13 @@ class IPBasedDistributor(Distributor): # If the client wasn't using a proxy, select the client's subring # based upon the client's subnet (modulo the total subrings): if not usingProxy: - mod = self.numberOfClusters + mod = self.totalSubrings # If there is a proxy subring, don't count it for the modulus: - if self.proxyCluster: + if self.proxySubring: mod -= 1 - return int(self._subnetToSubringHMAC(subnet)[:8], 16) % mod + return (int(self._subnetToSubringHMAC(subnet)[:8], 16) % mod) + 1 else: - return self.proxyCluster + return self.proxySubring
def mapClientToHashringPosition(self, interval, subnet): """Map the client to a position on a (sub)hashring, based upon the @@ -260,14 +259,14 @@ class IPBasedDistributor(Distributor): ``N_IP_CLUSTERS`` configuration option, as well as the number of ``PROXY_LIST_FILES``.
- Essentially, :data:`numberOfClusters` is set to the specified + Essentially, :data:`totalSubrings` is set to the specified ``N_IP_CLUSTERS``. All of the ``PROXY_LIST_FILES``, plus the list of Tor Exit relays (downloaded into memory with :script:`get-tor-exits`), are stored in :data:`proxies`, and the latter is added as an - additional cluster (such that :data:`numberOfClusters` becomes + additional cluster (such that :data:`totalSubrings` becomes ``N_IP_CLUSTERS + 1``). The number of subhashrings which this :class:`Distributor` has active in its hashring is then - :data:`numberOfClusters`, where the last cluster is reserved for all + :data:`totalSubrings`, where the last cluster is reserved for all :data:`proxies`.
As an example, if BridgeDB was configured with ``N_IP_CLUSTERS=4`` and @@ -302,14 +301,14 @@ class IPBasedDistributor(Distributor): logging.info("Prepopulating %s distributor hashrings..." % self.name)
for filterFn in [filterBridgesByIP4, filterBridgesByIP6]: - for cluster in range(1, self.numberOfClusters): - filters = self._buildHashringFilters([filterFn,], cluster) - key1 = getHMAC(self.splitter.key, "Order-Bridges-In-Ring-%d" % cluster) + for subring in range(1, self.totalSubrings + 1): + filters = self._buildHashringFilters([filterFn,], subring) + key1 = getHMAC(self.splitter.key, "Order-Bridges-In-Ring-%d" % subring) ring = bridgedb.Bridges.BridgeRing(key1, self.answerParameters) # For consistency with previous implementation of this method, # only set the "name" for "clusters" which are for this # distributor's proxies: - if cluster == self.proxyCluster: + if subring == self.proxySubring: ring.setName('{0} Proxy Ring'.format(self.name)) self.splitter.addRing(ring, filters, filterBridgesByRules(filters), @@ -319,10 +318,9 @@ class IPBasedDistributor(Distributor): """Assign a bridge to this distributor.""" self.splitter.insert(bridge)
- def _buildHashringFilters(self, previousFilters, clientCluster): - g = filterAssignBridgesToRing(self.splitter.hmac, - self.numberOfClusters, clientCluster) - previousFilters.append(g) + def _buildHashringFilters(self, previousFilters, subring): + f = filterAssignBridgesToRing(self.splitter.hmac, self.totalSubrings, subring) + previousFilters.append(f) return frozenset(previousFilters)
def getBridges(self, bridgeRequest, interval, N=1): @@ -352,20 +350,20 @@ class IPBasedDistributor(Distributor):
# First, check if the client's IP is one of the known :data:`proxies`: if bridgeRequest.client in self.proxies: - cluster = self.proxyCluster # The tag is a tag applied to a proxy IP address when it is added # to the bridgedb.proxy.ProxySet. For Tor Exit relays, the default # is 'exit_relay'. For other proxies loaded from the # PROXY_LIST_FILES config option, the default tag is the full # filename that the IP address originally came from. + usingProxy = True tag = self.proxies.getTag(bridgeRequest.client) logging.info("Client was from known proxy (tag: %s): %s" % (tag, bridgeRequest.client))
subnet = self.getSubnet(bridgeRequest.client, usingProxy) - cluster = self.mapSubnetToSubring(subnet, usingProxy) + subring = self.mapSubnetToSubring(subnet, usingProxy) position = self.mapClientToHashringPosition(interval, subnet) - filters = self._buildHashringFilters(bridgeRequest.filters, cluster) + filters = self._buildHashringFilters(bridgeRequest.filters, subring)
logging.debug("Client request within time interval: %s" % interval) logging.debug("Assigned client to subhashring %d/%d" % (subring, self.totalSubrings)) @@ -380,7 +378,7 @@ class IPBasedDistributor(Distributor): # Otherwise, construct a new hashring and populate it: else: logging.debug("Cache miss %s" % filters) - key1 = getHMAC(self.splitter.key, "Order-Bridges-In-Ring-%d" % cluster) + key1 = getHMAC(self.splitter.key, "Order-Bridges-In-Ring-%d" % subring) ring = bridgedb.Bridges.BridgeRing(key1, self.answerParameters) self.splitter.addRing(ring, filters, filterBridgesByRules(filters), populate_from=self.splitter.bridges) diff --git a/lib/bridgedb/Filters.py b/lib/bridgedb/Filters.py index aade069..94d4325 100644 --- a/lib/bridgedb/Filters.py +++ b/lib/bridgedb/Filters.py @@ -19,7 +19,7 @@ def filterAssignBridgesToRing(hmac, numRings, assignedRing): def _assignBridgesToRing(bridge): digest = hmac(bridge.getID()) pos = long( digest[:8], 16 ) - which = pos % numRings + which = pos % numRings + 1
if which == assignedRing: return True