IM-Filter is a firewalled daemon in C programming language made for GNU/Linux which examines and regulates ICQ communication.
IM-Filter is mainly designed to run at a gateway, allowing all ICQ-related traffic of LAN users to pass through it. However, it can also be directly used on end-users' computers. The daemon is highly modular, allowing plugins for other protocols like MSN or IRC to be written easily. The source code already contains skeleton code for an IRC module.
IM-Filter comes with adequate iptables scripts that ensure only ICQ traffic packets get into the netfilter queue of IM-Filter. This software provides robust features such as logging of messages sent via ICQ, identifying and logging messages, blacklists for messages and UINs, detection and blocking of file transfers, and a list with currently logged-in users.
IM-Filter can identify and log messages that have been sent via ICQ protocol, including a timestamp, IP-address, the appropriate UIN and the message itself. It can also handle two different blacklists, one for messages and another for UINs, such that blacklisted strings in messages get censored in the log files, while blacklisted UINs of users are not allowed to connect to the ICQ network.
This software can also detect and block file transfers using a specific command-line argument. Furthermore, it logs all file transfers, including the receiver's UIN, filename, and file size. IM-Filter manages a text file of all currently logged-in users' necessary information, including their UINs and IP addresses.
In the latest release, IM-Filter has added a branch for libipq, a sample iptables script for a gateway, and a check for the existence of /var/run/imfilter.pid. Plus, file permissions are checked before starting, and the daemon does not need SUID-Bit anymore. The IRC-module now must be compiled in explicitly via #ifdef.
Overall, IM-Filter is a reliable and robust software for GNU/Linux firewall hosts that provides an easy and effective way to analyze and filter the ICQ protocol and has useful features making it a great choice for network administrators.
Version 0.9: N/A