Modem Tapping?
 

Is there any possible way to prevent people from doing this? It's causing problems on Era aswell as on Unholy Nation.

Wow, thanks for using that term, I just learned something new.

Do you understand what I mean?

When you "Modem Tap", you usually pull the Ethernet Cord from you DSL/Cable/Router, and it allows you freedom to move for 5-10 seconds, then once you "reconnect" to the server (eg, modem picks back up and sends the data packets), you just warped around the room and managed to avoid death, heal, then kill everybody.

It's really annoying on Era, but REALLY annoying on Graal Kingdoms. -_-'

There really isn't a way to stop it, it's simular to lag, just a delay in the receiving/sending data packets... I guess you'll have to live with it. Enforce rules against it, etc.

You're using the incorrect term, but you help me stumble upon something very interesting :D

My modem is on another floor :/

You're kidding me... people actually pull out their modem cable?

yes, this was a very common practice on era, before the serverside hit detection was added

it is also common on UN

i have also heard it described as "putting tinfoil over my wireless router"

This isnt just used for graal, its also used to speed up a ****ty computer especially for downloading and uploading.

It works on Era now. People can kill people in 1 hit because of it :[

And then people with lousy connections would also be banned.

Is that the thing people do to change the images of their shields, helms, etc on Kingdoms?

Yes


http://img105.exs.cx/img105/3043/winky.gif

For a game!

They must be really bad at PKing if they depend on "Modem Tapping."

Or they just really want to kill the other person with the minimum ammount of effort...? Just because they abuse something to kill doesn't mean they suck, they could be lazy.

Grats -

Now about 30 forum browsers are going to log on Era and try this lovely fairly unknown trick. :rolleyes:

it's not as bad as un-named people on Era who use x y warp hack combined with speed hack

Cheaters will always be around forever you just need to learn how to deal with them, or atleast until someone really smart comes a long. That will be the day..

So, forever is just until someone smart comes along, and then time as we know it stops. I guess Kaimetsu really isn't that smart then!

Exactly, but I believe Kaimetsu is very smart however, their will always be a hacker just as good as the programmer.

Jenn will probably find a way around it, I just havn't confronted her :P.
I was hopeing there was something to do with the graal client and such

I fail to see how something like this would make you download faster. You'd actually get corrupt or incomplete packets...

I was just going to say the same :[

There are all kinds of ways to deal with abuse. Perhaps Graal's speedhack tolerance should be modified to consider the actual speed of the player, rather than just the number of data packets.

How would the actual speed of the player be a better choice for the speedhack detection than the frequency of data packets?

In that it covers a wider range of exploits, including the one described in this thread. It tackles the undesirable phenomenon directly.

In hindsight, I probably should've used the word 'extended' rather than 'modified'. Checking data packet frequency is still a good thing, I'd say.

I disagree. In this case, I see the crazy movement speed as just a symptom of all those packets being sent at once. Why tackle the symptom and not the problem? Also, can you provide some examples of these other exploits?

As far as I know, the system we already have should catch these "modem tappers". I think the biggest problem is that many servers don't even use the speedhack detection system. A quick check of UN shows that it isn't used at all. Another quick check shows that Era is using it but has an unreasonably high value for the tolerance (290). A value of 90 should catch most speedhackers. Stefan's words were that simple lag would not set off the alarm with a value of 90. Still, if it happens just once, warn them. If it happens quite frequently, you've got an abuser on your hands.

Movement packets are actually UDP datagrams, right? From what I understand of the protocol, it's a very fire-and-forget system. If the client tries to send them when the connection is down, they'll just fail and be forgotten. They don't enter any kind of queue, so it's not like the server will be receiving more than usual once the connection is reestablished.

Why tackle a single cause and not the problem?

The problem here is that players can move in ways that weren't intended. That is the problem. Your advised approach is like saying we should ban cigarettes so we don't have to bother looking for a cancer cure anymore.

Would it not currently be possible to send arbitrary movement packets? As long as I don't send too many of them, I can move as quickly as I want. I can warp randomly around the level as long as I don't exceed x packets per second.

u can make ur items invisable with moden tapping

Don't forget that Era uses graal2k2's system. I thought it was normal at 290 with it being changed to GK. So I didn't bother asking x-x. But Lance, That doesn't detect modem tappers.

I do not deny my ignorance of such protocols, but TCP is another option for Graal, and I do believe that TCP operates differently. If these packets were just ignored, then how would you explain this:

I've seen an individual player stop moving for some arbitrary length of time and then seen them start to move again, only they are moving faster than is possible along the paths they presumably walked along while they did not appear to move.

I still don't agree with your naming conventions here. I don't see the unintended movement as a problem of its own to address (like cancer is) but more as the visible effect of some other problems, much like a fever that is a symptom of some bacterial infection. Sure, you can take something to deal with the fever, but would it not be far more productive if you took something to deal with the bacteria? Sure, you can do both in this example, but I hardly think it's a good (or, better, as I initially inquired) idea to just treat the fever.

I just see a lot of problems with monitoring the player's actual speed. It just gets too complicated. What about servers that allow you to move quickly, staff boots, vehicles that allow you to move faster than you walk, etc.? Where do you draw the line? For example, if you don't let anyone move faster than, say, the trains on Graal2001, that's fast enough to render it relatively ineffective. Sure, the extreme moving-around would be limited, but you could still go as fast as a train.

If you had a method of sending such packets, could you not also use that method to cause some other trouble not related to movement? Then, would not the best method to deal with that problem be to remove the vulnerability that allows you to send such packets, rather than simply dealing with the movement packets you send?

Couldn't the server (when detecting a possible speed hack) clear the stacked data for projectiles etc and warp the player back to their location before this "lag spike" and possibly set back flags?

Now I read my own text I guess some of that probably wouldn't work x.x

Agreed. But only a minority of users are foolish enough to use TCP when UDP is a viable option.

Either way, operating the safeguard based on actual speed rather than packet frequency would solve the problem in both cases.

How does this suggest that undeliverable UDP datagrams are queued on the client computer? I would sooner think that all the player's movement packets have been sent, but traffic conditions force them into clumps somewhere between the player's client sending them, and you receiving the relays from the server.

Then perhaps we disagree on the definition of 'problem'. Clearly the movement is the part to which we object; it is the part that causes conflict with other users, grants unfair advantages, etc. It is the thing we want to stop.

Yes, I had considered this. It's quite a shame that we're not able to interact more directly with the gserver's code. It would be nice if we could completely redefine how the server reacts to each packet of information, according to various scripted conditions. The server knows if the character is on a vehicle, for example. In such a case, it should ignore all movement packets and let the NPC move the character.

Maximum speed would then be configurable per player, per situation, nullifying your objections.

Such as?

What vulnerability? The only requirement is an internet connection and an understanding of Graal's protocols.

It isn't a viable option for everyone, though. Some people are stuck behind routers and cannot set up port forwarding for those UDP packets. Other problems may exist, too. For example, when Nappa still used 56k, UDP was not working properly for him. Whenever he had Graal set to use UDP, it was horribly laggy. However, when setting it to use TCP, he did not have that problem.

The movement would be removed, sure. However, I already mentioned the problems with basing the safeguard on the actual speed.

I did not suggest that the undeliverable UDP datagrams were queued there. I was asking if the TCP option would allow for such a queur or if there was any other possible explanation for that behavior.

I'll attempt to clarify: Yes, the movement is a problem. However, I see it more as a symptom of another, perhaps more important problem (or problems) which need to be addressed.

It certainly would be nice, yes. Unfortunately, such is not the case, so it remains unfeasible.

Pretty much anything the client can do, such as setting ganis, setting clothes properties, firing weapons, or sending triggeractions.

A question occurred to me: If you sent such a packet that told the server you moved somewhere else, would it display this movement on your screen?

My apologies; I chose a poor word there. 'Oversight' would be more appropriate.

My Brain ;____;

Yes, when I was on 56k UDP wouldn't allow me to properly play. The lag was so horrible I couldn't even properly move (on GK).

http://img105.exs.cx/img105/3043/winky.gif

They always come up with new stuff, dont they?

Lol, it's common on online games for consoles. Although I didn't know it was called that, but infact I call it ''pulling the cord'', it has great effect on games such as shooting ones that require you to breach a base for example, as if someone pulls their cord they can breach the base, kill a few people and avoid mines/guards in about 1second when the lag catches up. (Although it may sound like it, I don't do it - that's just the effect is has ;))

Hell, there is a device made that has a switch on your ethernet cord so you can do it while you play without having to pull it directly out of your modem/router. You can make it at home for little, or pay some random joe to make it for you (As most young kids opt for >_< )

I'll sell anybody who wants one a box you simply clip on to your ethernet cord.

Push the button and it pushes a razor blade down, "interrupting" your connection "temporarily".

(until you get a new cord ;))

What if we are wireless ?

http://img105.exs.cx/img105/3043/winky.gif