python for windows internet filter / firewall

[thorley@gmail.com]

Greetings,

I'm interested in a simple content-based internet firewall/filter,
similar to dansguardian (http://dansguardian.org/), but written in
python, and for windows. I assumed such a project would already exist,
but my searches on freshmeat, and google turned up empty. I would be
interested in starting my own project if necessary, so I have two
questions:

1) Does any one no of such a project?

2) Is this even reasonable in python and how might I get started? (e.g.
win32 COM?)

Thanks much
--
matthew

[Diez B. Roggisch]

Re: python for windows internet filter / firewall

> 2) Is this even reasonable in python and how might I get started? (e.g.[color=blue]
> win32 COM?)[/color]

Don't know much (not to say nothing) about windows firewalling & the
interfaces one needs to talk to them.

But _what_ I know is: a firewall needs to be fast. The big guys in
networking put a lot of effort into pushing as much package processing as
possible into the hardware-layer.

And as much as I love python - I do not see it here, beyond a
proof-of-concept.

Diez

[thorley@gmail.com]

Re: python for windows internet filter / firewall

I thought speed might be an issue. At this point I'm not interested in
much more than toying around, so *if* there's a way to do it, I'd like
to explore the options.

--
matthew

Diez B. Roggisch wrote:[color=blue][color=green]
> > 2) Is this even reasonable in python and how might I get started? (e.g.
> > win32 COM?)[/color]
>
> Don't know much (not to say nothing) about windows firewalling & the
> interfaces one needs to talk to them.
>
> But _what_ I know is: a firewall needs to be fast. The big guys in
> networking put a lot of effort into pushing as much package processing as
> possible into the hardware-layer.
>
> And as much as I love python - I do not see it here, beyond a
> proof-of-concept.
>
> Diez[/color]

[Michele Petrazzo]

Re: python for windows internet filter / firewall

thorley@gmail.c om wrote:[color=blue]
> Greetings,
>
> I'm interested in a simple content-based internet firewall/filter,
> similar to dansguardian (http://dansguardian.org/),[/color]

Firewall and filter are two things totally separated!

- If you want to do something like a "page filtering", like dansguard
and squidguard, you can simple do it with python, because you have to
act like a proxy that leave of not visit a page.
- If you have to do a firewall... I think you can't, especially if you
are on win. Take a look at wipfw (wipfw.sf.net) that do what you want
[color=blue]
> but written in python,[/color]

Of course :)

and for windows.

Why? All that work with networking (and not only that) work better with
*nix OS!
[color=blue]
> I assumed such a project would already exist,[/color]

Firewall I don't think, and the same for the filtering (I know only
something like a plugin for squid, so for *nix platform).
[color=blue]
> but my searches on freshmeat, and google turned up empty. I would be
> interested in starting my own project if necessary, so I have two
> questions:
>
> 1) Does any one no of such a project?
>
> 2) Is this even reasonable in python and how might I get started?
> (e.g. win32 COM?)[/color]

win32COM for do what?

You can do it in not so difficult manner:
Take twisted and its proxy class, make some outline code (for filter the
pages) and enjoy! (work also on win)
[color=blue]
>
> Thanks much -- matthew
>[/color]


P.s. Don't forgot to share your code, when it'll work :)

Bye,
Michele

[thorley@gmail.com]

Re: python for windows internet filter / firewall

Thanks for a detailed reply.
[color=blue]
> Firewall and filter are two things totally separated![/color]

Sorry for being to general. I want to create a filter like
dansgaurdian. I was thinking of it also as a firewall because is
restricts traffic on a port based on content, but you're correct, they
aren't the same thing at all.
[color=blue]
> Take a look at wipfw (wipfw.sf.net) that do what you want[/color]

Thanks for the tip I'll check it out.
[color=blue]
> And for windows. Why? All that work with networking (and not only that) work better with
> *nix OS![/color]

Yes you are correct again. I am infact working on linux right now, and
it is my os of choice. How ever I need to deploy this on M$win :(
[color=blue]
> win32COM for do what?[/color]

My knowledge of COM is miniscule, but I assumed it has a low level
interface for packet filtering.
[color=blue]
> You can do it in not so difficult manner:
> Take twisted and its proxy class, make some outline code (for filter the
> pages) and enjoy! (work also on win)[/color]

Proxy would be an easy way, but I wanted to do it at a lower level.

Thanks again.
--matthew

[Michele Petrazzo]

Re: python for windows internet filter / firewall

thorley@gmail.c om wrote:[color=blue]
> Thanks for a detailed reply.
>[/color]

I thing that now we are becoming OT... :)
[color=blue]
> because is restricts traffic on a port based on content, but you're
> correct, they aren't the same thing at all.
>[/color]

So, what you want to do? Open and close a destination IP (domain),
following what the user see, with a firewall? It's so hard to do, and it
doesnt' sound like a good think. This is the work of a proxy, not of a
firewall.
[color=blue][color=green]
>> win32COM for do what?[/color]
>
> My knowledge of COM is miniscule, but I assumed it has a low level
> interface for packet filtering.
>[/color]

Yes, but you have to create a dll that work at low level and has an low
level features... Something like that wipfw do: create a .sys/.vxd (if I
remember correctly) that in your case are the dll and after with an exe
(that are the python program) that teach the rules... Very bas idea, for me!
[color=blue][color=green]
>> You can do it in not so difficult manner: Take twisted and its
>> proxy class, make some outline code (for filter the pages) and
>> enjoy! (work also on win)[/color]
>
> Proxy would be an easy way, but I wanted to do it at a lower level.
>[/color]

But you _can't_ with python. How you create a .sys/.vxd file? Also that
has only few kb program? And don't such more than few kb memory?

Keep the proxy way or switch to another language :)
[color=blue]
> Thanks again. --matthew
>[/color]

Michele