zode / gsdddoss

GoldSource Denied Distributed Denial of Service Script - automagically block offending ips!

GSDDDOSS (GoldSource Denied Distributed Denial of Service Script)

GSDDDOSS is a simple python script that monitors your goldsrc/svengine game server's udp log output for the following attacks: Bad Rcon, Split Packets, and A2S abuse / Reflected DDoS

Any ip associated with any of these attacks will be automagically blocked in the firewall.

(blame H2 for the name :P)

If you find a bug, or have improved on the script - feel free to make a pull request!

Requirements:

python 3.6 or greater.

Support:

Windows (tested)

Linux (untested, but should work)

Installation:

Download & run the script, it will automatically start listening on udp port 8008. In your server.cfg file add the line: logaddress_add 127.0.0.1 8008

and either restart the server, or rcon the same line in the server console.

note: ideally you wanna run the python command in a loop in case it crashes or something, use screen or tmux on linux.

Windows .bat trick for lazy administrator:

(this assumes python3 is added in PATH)

Make a new .bat file containing:

@echo off
title GSDDDOSS
:watch
python gsdddoss.py
goto watch

After that make a shortcut to the bat file, and go to the shortcut properties.

In the shortcut properties find the button labeled "Advanced" and tick off "Run as administrator".

Then you just run the shortcut and press yes during UAC

gsdddoss's Issues

UnicodeDecodeError: invalid continuation byte

Sometimes I am getting the error UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd8 in position 221: invalid continuation byte and the script fatally exits. Would be great to make this error non-fatal, maybe by using try/expect or something.

Jan 23 17:12:55 twlz python3[1573471]: Udp started: 127.0.0.1:8008
Jan 23 17:12:55 twlz python3[1573471]: INFINITE LOOP; ^C WILL MOST LIKELY NOT WORK!
Jan 23 17:12:55 twlz python3[1573471]: Traceback (most recent call last):
Jan 23 17:12:55 twlz python3[1573471]:   File "/home/svends/gsdddoss.py", line 101, in <module>
Jan 23 17:12:55 twlz python3[1573471]:     for data in udp_server():
Jan 23 17:12:55 twlz python3[1573471]:   File "/home/svends/gsdddoss.py", line 99, in udp_server
Jan 23 17:12:55 twlz python3[1573471]:     yield data[4:-1].decode("utf-8") # has garbag header + ending
Jan 23 17:12:55 twlz python3[1573471]: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd8 in position 221: invalid continuation byte
Jan 23 17:12:55 twlz systemd[1]: gsdddoss.service: Main process exited, code=exited, status=1/FAILURE
Jan 23 17:12:55 twlz systemd[1]: gsdddoss.service: Failed with result 'exit-code'.
Jan 23 17:13:00 twlz systemd[1]: gsdddoss.service: Scheduled restart job, restart counter is at 82.
Jan 23 17:13:00 twlz systemd[1]: Stopped gsdddoss.
Jan 23 17:13:00 twlz systemd[1]: Started gsdddoss.

Additional infos:
Linux, Python 3.10.9,