python-nflog

Python module to read from nflog.

Usage

This is a basic example, the nf_callback_packet_handler obviously needs to be filld with something that actually does someting with the packet.

def nf_callback_packet_handler(
      indev,        # (int) Inbound network device number
      outdev,       # (int) Outbound network device number
      ifname,       # (str) Network device name
      proto,        # (int) Ethertype, see net/ethernet.h
      payload_len,  # (int) Length of payload
      payload,      # (bytes) Payload
      hw_hdr_len,   # (int) Length of hardware link-layer header
      hw_hdr,       # (bytes) Hardware header
    ):
  pass

import nflog
nflog.setgroup(1) 

nflog.setcb( nf_callback_packet_handler )
nflog.start()
n = nflog.handle()

Too make all the above work, you also have to have setup nflog rules in your packetfilter! And use the right group, once started the group can not be changed.

Install

This packet depends on libnetfilter_log, so make sure that it is installed. Building and installing, is just normal procedure:

python setup.py build
python setup.py install