Useful description follows this license.

The MIT License

Copyright (c) 2009 Nathan Gallaher <ngallaher @ deepthought.org>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

Description:
------------

Teflon is an auto-start proxy service designed to startup your ssh
proxy on demand. It is designed to be used in conjunction with a web browser
proxy, eg: foxy-proxy, though it can be used as the canonical proxy target
for any application.

Teflon is a simple script that will ensure your ssh proxy is up when your
browser needs to request something.  Teflon is different from autossh in that
autossh will continually attempt to establish a connection, even if
that connection is not needed.  Teflon only checks the health of your proxy
connection when you request something over it. Teflon can be configured to
leverage autossh's connection monitoring facilities to produce a very
transparent tunneled proxy.

Teflon's target audience is people who are highly mobile who need to access
content that is only available within specific networks. For example, your
office or university might have websites that are only viewable if you are
on a computer within that network.  Using teflon with foxyproxy, you can
seamlessly view pages on such networks, without having to constantly
re-establish your proxy tunnels each time.

Installation:
-------------

Unpack teflon somewhere. There are 2 files included: the teflon script, and
its config file.

Install the python configobj module. This can be found in most major
repositories for linux. For OSX, try fink. For windows or distros that do not
have a configobj package, you can download it from
http://www.voidspace.org.uk/python/configobj.html and use the setup.py
installer.

Install autossh. This is recommended but not strictly necessary. If you
do not wish to use autossh you will have to add 'proxy_application=ssh'
to each entry in your config.

If you haven't already, push your ssh keys to the target linux server.
Currently teflon only works if you can use public key authentication. Teflon
does not support password authentication (patches are being accepted)

Running:
--------

1) edit teflon.conf and setup your login info. Choose a local_socks_port that
is in the 2000-60000 range that is unused. Almost all ports in that range are
likely to be unused.

2) run ./teflon.py &

3) Setup your webrowser to use a SOCKS proxy on the local_socks_port
   on the host 127.0.0.1 (localhost)
   You may have to twiddle network.proxy.sock_remote_dns on the
   about:config page to get dns lookups doing the right thing.
   It is recommended that you install FoxyProxy or a similar plugin
   to only send the restricted traffic over the proxy interface.
   Teflon is not particularly slow, but it would be needless to
   tunnel all of your traffic if you don't need to.

4) Browse to a previously restricted page. In the terminal where you
   started teflon, you should see a "Starting proxy via host <host>"
   message. If you see nothing, check your proxy settings. If you see
   an error, check your config file, and check that you can login
   to the remote_host without having to enter a password

Geeky explanation:
------------------

Teflon listens on localhost:local_socks_port for connections from clients.
Upon receiving a connection, a quick check is done to see if an ssh proxy
is listening for traffic on local_socks_port+1 (you can change this). If it
is, the proxy is assumed to be up, and teflon merely shuttles data between the
ports. If the port is closed, then teflon attempts to start the ssh proxy
(by default autossh -D). Using autossh allows for connections to fail
fast, solving a particular problem when laptops are put to sleep in the
middle of a connection.  Autossh needs ports local_socks_port+2 and +3, so if
you have multiple targets for teflon to handle, make sure you space
local_socks_port directives by at least 4 portnumbers.

Caveats:
--------
Proxy tunneling like this can be a security hazard. If you share your local
machine with others, it is not recommended that you leave teflon running. If
you can share your machine with remote users, it is not recommended that you
use teflon. This is because the local ssh proxy tunnel you are starting can
be accessed by anyone on your local machine.

Contributing:
-------------
Teflon was written on a whim to solve a particular problem.  Not much attention
was paid to portability, non-*nix platforms, or code cleanliness/usability.
If you have questions, concerns, are not sure if teflon can do X, or would like
to submit patches, feel free to email me at <ngallaher @ deepthought.org>