TorFlow


TorFlow is a set of python scripts written to scan the Tor network for
misbehaving, misconfigured, and overloaded Tor nodes. The ultimate goal
is to build an automated, distributed reputation system that feeds into
the directory servers and provides them with information on the
reliability, capacity, and trustworthiness of routers, so that they can
set flags that clients can use in routing decisions. 

This is admittedly a lofty goal. In the meantime it should be able to
figure out a bunch of neat stuff about Tor. 


TorFlow consists of the following components:

1. TorCtl package

TorCtl is an updated version of the python Tor controller written by
Nick Mathewson with extensions to support path building and various
constraints on node and path selection.

The basic structure is that the EventHandler class in TorCtl.py receives
Tor controller events packaged into python classes. PathSupport.py
provides a PathBuilder class that extends from EventHandler that handles
circuit construction and stream attachment subject to policies defined
by NodeRestrictor and PathRestrictor implementations. StatsSupport.py
gathers statistics on the circuits and streams built by PathSupport.

The TorCtl package is now fully pydoced. From this directory, you can 
do:

# pydoc TorCtl.TorCtl
and 
# pydoc TorCtl.PathSupport
and
# pydoc TorCtl.StatsSupport


2. metatroller.py 

Metatroller is a wrapper around StatsSupport that provides a
meta-control port for use by Tor scanners.

The metatroller is also pydoced. To view the documentation, you can do:

# pydoc metatroller


3. Network Scanners

3a. NetworkScanners/soat.py

SoaT provides tests for ensuring the honesty of exit nodes. It can check for
invalid exit policies and perform tests to see whether nodes are changing
the requested content for several protocols. See the soat README for
details:

# cd NetworkScanners ; cat ExitAuthority/README.ExitScanning

Important note: soat requires the pyopenssl python module to run.
You can check if pyopenssl package is available for your distribution
(python-pyopenssl for debian/ubuntu, pyOpenSSL for fedora etc)
or get it from http://pyopenssl.sourceforge.net/ 


3b. NetworkScanners/speedracer.py

SpeedRacer fetches a file repeatedly through circuits built by
metatroller. It divides the Tor network into tiers based on percentiles
of directory-reported node bandwidth and compiles statistics for each of
these tiers itself and via metatroller.

A README for gathering performance metrics with speedracer can be
found in README.PerfMeasurements.

4. Circuit Analysis

4a. Build Time Anlysis

The set of scripts under CircuitAnalysis/BuildTimes gathers and plots
circuit construction times and fits a pareto curve to the results.

A README for gathering performance metrics with buildtimes can be
found in README.PerfMeasurements.


4b. OP Addon

In CircuitAnalysis/OPAddon is a utility designed to run along side a Tor
client to build a map of latencies between nodes on the network, and to
then use this map for future routing decisions. See
CircuitAnalysis/OPAddon/README for more info.


5. Node Monitors

6a. NodeMonitors/nodemon.py

Nodemon uses TorCtl to monitor ORCONN events on a Tor node to measure
how much bandwidth is going to each peer node. It also measures how many
circuits are killed by OR connections being shut down prematurely.

6b. NodeMonitors/moniTor.py

This is a "top-like" interface for Tor information It's goal at the
start is to just tell you basic information In the future, you may be
able to control Tor with it.



Each of these components has a lot of room for improvement. Please see
the TODO file for more information.