Diverting sockets and streams

[Julian Elischer]

Jakub Bednar wrote:
> Hi Julian,
> 
>                   thanks for making this clear to me.
> 
>>
>>>
>>> so basically I have to implement part of the TCP stack in my app.
>>
>> yes,
>> though there may be other ways to do what you want..
>> what DO you want to do?
>>
> 
> I need to make a transparent proxy e.g. HTTP proxy, that will be able to 
> scan the data stream for some security problems (exploits or whatever).
> 
> I had a solution based on packet forwarding and packet UID matching 
> rather then divert sockets. This solution works fine on FreeBSD, Linux 
> and Mac OS X Leopard. Hovewer in the new Mac OS X Snow Leopard, 
> forwarding outgoing packets to local port does not work. So I'm looking 
> for another solution.

sounds like the broke it..

maybe they inherited a change from FreeBSD that was reverted out but 
existed for one release, that broke exactly that :-)

ipfw fwd
along with fwd uid
is the way to do this on FreeBSD but snow leopard IS a problem.

doing it with divert is going to be a real pain.


you can also do this with nat in some cases I think..


> 
> Jakub