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  1. NFQueue bindings (2)

    The code for nfqueue-bindings is now almost ready, I have made some progress since last week:

    • you can now modify packets in live, and send the new packet with the verdict
    • new functions are wrapped, and the creation of the queue can be done in one function
    • more examples

    I have presented a special script for SSTIC, using the weather to decide if a packet should be accepted or dropped :)While the utility of the module still has to be proven, it is a good example of how easy it is to use the new bindings.

    The slides can be found online here, and contains some code examples (with some funny things ;). They are in french, but they should be quite easy to understand.

    Random ideas:

    • The Netfilter workshop will be held in Paris from 30 September to 3 October 2008.
    • Eric has presented nf3d, a nice tool to view netfilter logs (from ulogd2) in 3D.

    Gamers will recognize a nice try to convert network logs into Guitar Hero tracks ;)

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  2. NFQueue bindings

    I am currently working (amongst other projects ..) on nfqueue-bindings, set of high-level modules for several languages (Python and Perl, for the moment), for libnetfilter_queue.

    The goal is to provide a library to gain access to packets queued by the kernel packet filter. For more details, see nfqueue-bindings project site.

    Current state

    Actually, you can

    • access the module in Perl or Python
    • create a queue connected to netfilter
    • register a callback
    • access the contents of the packet. As I do not want to do what was already done many times, I use some other libraries to decode the packet:
    • NetPacket::IP for Perl
    • dpkg for Python.
      • If you know some other libraries, please let me know.
    • set the verdict (decision) to ACCEPT or DROP for the packet

    I have written some scripts to show what can be done in a few lines of code. The current examples are:

    I will make a release as soon as the code is stable (and can be installed).


    Create and bind the queue (Perl)

    use nfqueue;
    use …
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