netfilter + perl payload mangling in userspace

netfilter + perl payload mangling in userspace

[Trixter aka Bret McDanel]

I wanted to modify the payload of packets in userspace, preferably with
perl.  I have tried to google to find something, encountered some dead
links.  I have not be able to get the example Net::Divert to work,
however it appears that I am not able to divert properly.  I cant find
any working examples of how to do the iptables command to divert.  

Is there any other way to modify the payload of a packet from userspace,
preferably with perl?

can someone provide me with a working example of how to do iptables to
divert?


I have iptables 1.4.1.1 on eeebuntu (ubuntu base) and a kernel of 2.6.27

Thank you
-- 
Trixter http://www.0xdecafbad.com     Bret McDanel
pgp key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8AE5C721

Re: netfilter + perl payload mangling in userspace

[Michael Mefford]

Trixter aka Bret McDanel wrote:
> I wanted to modify the payload of packets in userspace, preferably with
> perl.  I have tried to google to find something, encountered some dead
> links.  I have not be able to get the example Net::Divert to work,
> however it appears that I am not able to divert properly.  I cant find
> any working examples of how to do the iptables command to divert.  
>
> Is there any other way to modify the payload of a packet from userspace,
> preferably with perl?
>
> can someone provide me with a working example of how to do iptables to
> divert?
>
>
> I have iptables 1.4.1.1 on eeebuntu (ubuntu base) and a kernel of 2.6.27
>
> Thank you
>   

Have you tried using NFQUEUE?  The queue is provided to 'queue' packets 
for userspace processing.  To use the queue, you'll need the 
libnetfilter_queue API.  Start here:

http://www.netfilter.org/projects/libnetfilter_queue/index.html

If you need more help, let me know.


Michael.