8 replies to this topic

[Liorana]

I was wondering how can you prevent packet attack with UDP.
There is no way to tell what ip it came from as far as I know other then with a firewall.
So if someone send a bunch of random packet to the server that's going to mess with everyone's packed obvious.

Any ideas?

[slayer 64]

are you sure?

[Liorana]

are you sure?

well it doesn't ask for any authentication at all, it's just "I open my door and you guys send me stuff."

[slayer 64]

i thought that was what udp was for. just send and forget about it

[michael pw]

use LastIP() to check who actually sent the packet (in terms of their ip adress) to the server rather than allowing an ID variable to get scanned.

[Liorana]

use LastIP() to check who actually sent the packet (in terms of their ip adress) to the server rather than allowing an ID variable to get scanned.

that doesnt help if there is 10-20 people connected to the server sending data all the time
chance that you get the one that is attacking is pretty damn low

Edited by Liorana, 19 June 2012 - 02:51 AM.

[slayer 64]

who the heck is gpoing to udp attack you? that's like being pinged to death, networks are so dam fast now, it doesn't even matter. just make a good game so i can play it.

[Liorana]

who the heck is gpoing to udp attack you? that's like being pinged to death, networks are so dam fast now, it doesn't even matter. just make a good game so i can play it.

It has nothing to do with being fast... It has to do with 39dll mixing all packet into 1 so there is no way to differentiated where a new packet start so if i just make up 1 random packet it will mess up every other packet along with it

Lets say I make the start of a packet 255 and I close it with 254.
So I get all those packet from people that start with 255 and end with 254. what happen if someone send me a random packet that goes like this
(34 , 162 , 255 , 12 , 254 , 32 , 255) since it mix all packet into 1, there is no way for me to tell where the next real packet is going to start at, I guess I would have to make a special check to see if what follows is legitimate but that seems pretty hard. I'm not sure how I would do that.

So all you would need is 1 person sending a random packet constantly and it would mess up everyone else.
This kind of thing can happen if you try to build a small community for your game and random people play it together.
It's not like "Oh people only play it with friends. Who would ever try to attack them."
So how are you going to prevent that in your game? Right now I like the idea of udp being fast but it seems really flawed to me right now without any protection for that.

[PrimuS]

Dem, i don't quite get it. Whaddyamean, mixing all packets into one? Every packet has a header specifying its size, source and destination.
If i do understand how this thing works, the packets get added at the end of the specified buffer (if it's not cleared), like, one whole packet at a time, not a random chunk of data and not in a random position, and you can register when something comes in, so you just process them the same time they come in, cause then you know exactly what was in that packet and what's its size, where did it come from or whatever. You can register IPs constantly sending garbage and make the server ignore packets from em.
There are also the lastinIp() and lastinPort() functions, if you were talking about that in the first post.

Edited by PrimuS, 24 June 2012 - 10:20 PM.