MovedTooQuicklyEvent (when someone in a server moves too quickly)

[randomdude999]

I've seen a few mods that allow some form of moving really fast. Not like teleportation (lots of mods to that), but actually setting the player's movement vector to something really big. These work fine in singleplayer, but in multiplayer they get you a handful of blocks forward before the server's "anti-cheat protection" kicks in, stopping the player right there. Currently there is no way to stop that. There is a common misconception that this can be stopped by setting the gamerule "disableElytraMovementCheck" to true. That only works if the player is flying with the elytra. If you're flying with the elytra you don't need anything else to give you a speed boost, especially not after 1.11.1 (which adds firework boosting).

 

This event would be fired in net.minecraft.network.NetServerPlayHandler function processPlayer, line [search for "moved too quickly!"]. If it gets canceled, then the player is not stopped and a message is not logged.

I'd happily code this myself, but I have no idea how exactly Forge patches Minecraft. Basically, it would change

 

LOGGER.warn("{} moved too quickly! {},{},{}", new Object[] {this.playerEntity.getName(), Double.valueOf(d7), Double.valueOf(d8), Double.valueOf(d9)});
this.setPlayerLocation(this.playerEntity.posX, this.playerEntity.posY, this.playerEntity.posZ, this.playerEntity.rotationYaw, this.playerEntity.rotationPitch);
return;

 

to

 

net.minecraftforge.event.entity.player.MovedTooQuicklyEvent event = new net.minecraftforge.event.entity.player.MovedTooQuicklyEvent(this.playerEntity);
if (!net.minecraftforge.common.MinecraftForge.EVENT_BUS.post(event)) {
    LOGGER.warn("{} moved too quickly! {},{},{}", new Object[] {this.playerEntity.getName(), Double.valueOf(d7), Double.valueOf(d8), Double.valueOf(d9)});
    this.setPlayerLocation(this.playerEntity.posX, this.playerEntity.posY, this.playerEntity.posZ, this.playerEntity.rotationYaw, this.playerEntity.rotationPitch);
    return;
}

 

Then of course, it needs an event class too. Just a generic Forge event.

 

package net.minecraftforge.event.entity.player;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraftforge.fml.common.eventhandler.Cancelable;

/**
* When the player moves "too quickly" according to the server. 
*/
@Cancelable
public class MovedTooQuicklyEvent extends PlayerEvent {

    public MovedTooQuicklyEvent(EntityPlayer player)
    {
        super(player);
    }
}

 

This would mean that mods can listen for that event, and when it fires, they can check the player's inventory / something in the world near the player / a NBT tag on the player and when it tells them the player is supposed to move fast, they can cancel the event.