Post: #1

Hello PPl,

what do you use to control/block fast walking?

I had a script that counts the number of steps one player can do in a tick. It didn't works fine, so i've done the same thing by filtering the packet 0x2 (movement request). Actually a player can do 19 steps (mouted) per tick. Sometimes the players with good conexions make 20-23 steps.

The problem is that sometimes some players can reach 28-29 steps (valid steps) in one tick, without Change Speed.

I've tried to do this procedure (that i've found at pol documentation) but i've never an invalid key

Fastwalk prevention notes: each 0x02 pops the top element from fastwalk key stack. (0xbf sub1 init. fastwalk stack, 0xbf sub2 pushes an element to stack)
If stack is empty key value is 0. (-> never set keys to 0 in 0xbf sub 1/2)
Because client sometimes sends bursts of 0x02's DON'T check for a certain top stack value.
The only safe way to detect fastwalk: push a key after EACH 0x21, 0x22, (=send 0xbf sub 2) check in 0x02 for stack emptyness.

If empty -> fastwalk alert.
Note that actual key values are irrelevant. (just don't use 0)
Of course without perfect 0x02/0x21/0x22 synch (serverside) it's useless to use fastwalk detection.
Last but not least: fastwalk detection adds 9 bytes per step and player !


What do you do to block change speed?
Why some players can reach 29 steps per tick without CS?

Example:
-
Relatorio de 2013/01/06 18:50:25
20 steps: 12 times.
21 steps: 7 times.
22 steps: 5 times.
23 steps: 1 times.
-
Relatorio de 2013/01/06 18:51:25
20 steps: 7 vezes.
21 steps: 1 vezes.
-
Relatorio de 2013/01/06 18:52:26
20 steps: 5 vezes.
21 steps: 3 vezes.
-
Relatorio de 2013/01/06 18:53:27
20 steps: 8 vezes.
21 steps: 2 vezes.
22 steps: 2 vezes.
-
Relatorio de 2013/01/05 18:18:38
20 passos: 3 vezes.
21 passos: 3 vezes.
22 passos: 3 vezes.
23 passos: 3 vezes.
24 passos: 3 vezes.
25 passos: 3 vezes.
26 passos: 2 vezes.
27 passos: 1 vezes.

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I also realized that when someone uses change speed the client is desynchronized so many times, with this method i could detect 1.1 CS, but the problem is when the player uses some command to resyncronize like ,resend (injection). I can't detect when the player use this command (it dont send 0x22) =(