DEPRECATED

Please use "UseDDBAsWhitelist" feature (introduced in rtlsdr-ogn v0.2.4) instead

OGN Privacy Filter

A script to selectively forward APRS packets.

The script listens for incoming connections by ogn-decode and connects to an APRS-Server (aprs-pool.glidernet.org). Every hour it fetches the DDB to update the local whitelist.

Received packets from the station are only forwared if the NoTrack-Flag in the DDB is not set ('Opt-In') or if they are from the station itself. All the packets from the APRS-Server are forwarded to the station.

Installation

1. Get the dependencies via pip or manual installion.

   sudo apt-get intall python3-pip
   sudo pip3 install aprslib requests
   

   or

   $ sudo apt-get install python3-setuptools python3-requests
   $ wget https://pypi.python.org/packages/source/a/aprslib/aprslib-0.6.40.tar.gz
   $ tar xzf aprslib-0.6.40.tar.gz
   $ cd aprslib-0.6.40/
   $ sudo pyton3 setup.py install
   

2. Clone Repository

   $ git clone https://github.com/kerel-fs/ogn-privacy-filter.git /opt/ogn-privacy-filter
   

3. Configure ogn-decode / manipulate DNS cache

   Currently (v0.2.3) you can't configure the address ogn-decode connects to (aprs.glidernet.org is hardcoded), so you have to manipulate your local DNS cache.

   Set the address ogn-decode connects to in the receiver configuration file.

   $ sudo vi /etc/rtlsdr-ogn/site.conf
   
   APRS:
   { Call = "N0CALL";
     Server = "127.0.2.1:14580";
   } ;
   

4. Install as service

   To install it as a service, edit your shellbox configuration file:

   $ sudo vi /etc/rtlsdr-ogn.conf
   
   #shellbox configuration file
   #port  user    directory           command      args
   50002  ogn /opt/ogn-privacy-filter ./privacyFilter.py
   50000  ogn /opt/rtlsdr-ogn         ./ogn-rf     /etc/rtlsdr-ogn/site.conf
   50001  ogn /opt/rtlsdr-ogn         ./ogn-decode /etc/rtlsdr-ogn/site.conf
   

And finally:

$ sudo service rtlsdr-ogn start

Development

For testing purposes, you can run it from the command line:

$ cd ogn-privacy-filter
$ ./privacyFilter.py
Listen for new client at 127.0.2.1:14580
Connected to server 37.187.40.234:14580
[...]

To get debug messages, create a short startup script:

#!/usr/bin/env python3

import logging
from privacyFilter import privacyFilter


if __name__ == "__main__":
    FORMAT = '%(asctime)-15s %(levelname)-5s %(message)s'
    logging.basicConfig(format=FORMAT, level=logging.DEBUG)

    client_adress = ('127.0.2.1', 14580)
    server_address = ('aprs-pool.glidernet.org', 14580)
    ddbInterval = 3600

    f = privacyFilter(clients_address, server_address, ddbInterval)
    f.logger.setLevel(logging.DEBUG)
    f.run()

TODO

Some minor improvements are necessary / should be considered.

• Clear *_queues if connection get closed?
• Check output of socket.send() for remaining data?
• Missing prefix generation in ognutils.py

License

Licensed under the GPLv3.