commit 98859a1e367c4b5728fb0d7bc2c5acf8e99d2208 Author: Sathyanarayanan Gunasekaran gsathya.ceg@gmail.com Date: Thu Jul 5 10:08:40 2012 +0200

Take into account the router flags

Measure entropy for exit and guard nodes --- task-6232/pyentropy.py | 45 ++++++++++++++++++++++++++++++++++++--------- 1 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/task-6232/pyentropy.py b/task-6232/pyentropy.py index 226aca8..6fa5b86 100644 --- a/task-6232/pyentropy.py +++ b/task-6232/pyentropy.py @@ -1,6 +1,6 @@ """ Usage - python pyentropy.py <consensus-dir> <output-file> -Output - A CSV file of the format <valid-after>,<entropy> +Output - A CSV file of the format <valid-after>,<entropy for all nodes>,<entropy for exitnodes>,<entropy for guardnodes> rsync -arz --delete metrics.torproject.org::metrics-recent/relay-descriptors/consensuses in """

@@ -20,6 +20,8 @@ class Router: self.bandwidth = None self.flags = None self.probability = None + self.is_exit = None + self.is_guard = None

def add(self, key, values): if key == 'r': @@ -28,7 +30,11 @@ class Router: self.bandwidth = int(values[0].split('=')[1]) if key == 's': self.flags = values - + if "Exit" in self.flags: + self.is_exit = True + if "Guard" in self.flags: + self.is_guard = True + def run(file_name): routers = [] # parse consensus @@ -47,11 +53,22 @@ def run(file_name): elif key in KEYS: router.add(key, values)

- # build hash table with freq. distribution - # key: bandwidth - # value: number of bandwidth's observations - bw_dist = {} + # build hash table with freq. distribution + # key: bandwidth + # value: number of bandwidth's observations + + bw_dist, bw_dist_exit, bw_dist_guard = {}, {}, {} for router in routers: + if router.is_exit: + if bw_dist_exit.has_key(router.bandwidth): + bw_dist_exit[router.bandwidth] += 1 + else: + bw_dist_exit[router.bandwidth] = 1 + if router.is_guard: + if bw_dist_guard.has_key(router.bandwidth): + bw_dist_guard[router.bandwidth] += 1 + else: + bw_dist_guard[router.bandwidth] = 1 if bw_dist.has_key(router.bandwidth): bw_dist[router.bandwidth] += 1 else: @@ -61,13 +78,23 @@ def run(file_name): print "Error: amount of routers must be > 0." return;

- entropy = 0.0 + entropy, entropy_exit, entropy_guard = 0.0, 0.0, 0.0 for bw in bw_dist.iterkeys(): - # p = probability of one particular bandwidth + # p = probability of one particular bandwidth p = float(bw_dist[bw]) / len(routers) entropy += -(p * math.log(p, 2)) + + for bw in bw_dist_exit.iterkeys(): + # p = probability of one particular bandwidth + p = float(bw_dist[bw]) / len(routers) + entropy_exit += -(p * math.log(p, 2)) + + for bw in bw_dist_guard.iterkeys(): + # p = probability of one particular bandwidth + p = float(bw_dist[bw]) / len(routers) + entropy_guard += -(p * math.log(p, 2))

- return ",".join([valid_after, str(entropy)]) + return ",".join([valid_after, str(entropy), str(entropy_exit), str(entropy_guard)])

def usage(): print "Usage - python pyentropy.py <consensus-dir> <output-file>"