There's several things wrong with this.
1) SRB2 is written in C. Not C++.
2) The main website has the entire source code.
3) The master server code is included in the source. That is also not written in C++.
4) As I understand it, the netcode is not merely one file, but interacts with the entire structure of the game in order to relay information. If you want to fix it, be prepared to be tinkering with the engine.
I have a hard time believing you can fix the netcode if you've already missed these things. Feel free to try, but really, if you're just trying to get started and already have these misconceptions, I'm very skeptical on your ability to actually do so.
Also, locking this because, while I understand this is a forum about editing SRB2, the reality is that most people in this forum are actually not qualified to be answering your questions on this. You're going to need help in actual programming, and we just aren't equipped to teach that. You'd have better luck in our IRC channel, but even then, only a very few people have the ability to provide meaningful help.
