On packet send/recieve events

[cookiedragon234]

Hi, just wondering if there are any events that are triggered once a packet is sent/recieved?

 

There are many things that I would like to do with this functionality, such as measuring a servers tickrate based on counting the frequency of server update packets.

 

If these events do not exist, is there another way to do it like each tick seeing each packet that is going to be sent during that tick?

 

Thanks

[diesieben07]

There are no events fired for vanilla packets.

[cookiedragon234]

4 minutes ago, diesieben07 said:

There are no events fired for vanilla packets.

Like I said in the second part of my post is there a way to perhaps each tick fetch the packets that have been handled that tick?

[diesieben07]

There are ways to listen to packets. But it's usually a really bad idea because you can break things. If you dig into the code it's pretty easy to figure out what to do though. Hint: Netty.

[cookiedragon234]

For anyone else looking for this in the future, create mixins for net.minecraft.network.NetworkManager like so:

@Inject(method = "sendPacket(Lnet/minecraft/network/Packet;)V", at = @At("HEAD"), cancellable = true)
private void onSendPacket(Packet<?> packet, CallbackInfo callbackInfo)
{
	//System.out.println("Packet Sent: " + packet.toString());
	PacketSent event = new PacketSent(packet);
	MinecraftForge.EVENT_BUS.post(event);
	if (event.isCanceled() && callbackInfo.isCancellable())
	{
		callbackInfo.cancel();
	}
	packet = event.packet;
}
	
@Inject(method = "channelRead0", at = @At("HEAD"), cancellable = true)
private void onChannelRead(ChannelHandlerContext context, Packet<?> packet, CallbackInfo callbackInfo)
{
	//System.out.println("Packet Recieved: " + packet.toString());
	PacketRecieved event = new PacketRecieved(packet);
	MinecraftForge.EVENT_BUS.post(event);
	if (event.isCanceled() && callbackInfo.isCancellable())
	{
		callbackInfo.cancel();
	}
	packet = event.packet;
}

PacketSent and PacketRecieved are custom events that you can make yourself by making a class that extends Event.

[diesieben07]

That's the worst way to do this.

[cookiedragon234]

On 8/13/2019 at 4:23 PM, diesieben07 said:

That's the worst way to do this.

I’d welcome any examples of a better way to do this?

[DaemonUmbra]

Best thing would be to not mess with it at all, may I ask why you need to interact with Vanilla packets?

[cookiedragon234]

5 minutes ago, DaemonUmbra said:

Best thing would be to not mess with it at all, may I ask why you need to interact with Vanilla packets?

Scroll up. Also I don’t understand why me literally offering helpful advice to other people coming across this is met with “that’s a shit method” and “don’t mess with it at all”. Like geez, if you know a better way then feel free to contribute, but simply getting complaining isn’t contributing anything.

[DaemonUmbra]

Because the best case for checking server tickrate would be to make your mod check the tickrate on the server side and send that info to your mod on the client side.

I don't understand this fascination with manipulating vanilla packets when having a server component of your mod is far safer and more reliable.

[Animefan8888]

3 hours ago, cookiedragon234 said:

I’d welcome any examples of a better way to do this?

On 8/4/2019 at 10:08 AM, diesieben07 said:

There are ways to listen to packets. But it's usually a really bad idea because you can break things. If you dig into the code it's pretty easy to figure out what to do though. Hint: Netty. 

Huh I wonder who gave you advice you just ignored.

[cookiedragon234]

11 hours ago, DaemonUmbra said:

Because the best case for checking server tickrate would be to make your mod check the tickrate on the server side and send that info to your mod on the client side.

 I don't understand this fascination with manipulating vanilla packets when having a server component of your mod is far safer and more reliable.

The mod is designed to be client side only

[cookiedragon234]

8 hours ago, Animefan8888 said:

Huh I wonder who gave you advice you just ignored.

Yes, and the mixin I just described is mixing into the netty networkmanager. I know its netty because when printing from the network manager it tells me that it is in the "netty" thread. I did dig into the code, and I found the class from which packets are sent and recieved, so I made a mixin to intercept the function calls.

Edited August 17, 2019 by cookiedragon234

[diesieben07]

6 minutes ago, cookiedragon234 said:

Yes, and the mixin I just described is mixing into the netty networkmanager. I know its netty because when printing from the network manager it tells me that it is in the "netty" thread. I did dig into the code, and I found the class from which packets are sent and recieved, so I made a mixin to intercept the function calls.

This shows you don't know how Netty works. Netty is based around a pipeline. This pipeline is mutable. You can put your own stuff in it. Without coremods.

[cookiedragon234]

13 minutes ago, diesieben07 said:

This shows you don't know how Netty works. Netty is based around a pipeline. This pipeline is mutable. You can put your own stuff in it. Without coremods.

Could you provide some examples?

 

I'm simply using mixins because I know it works and I've seen many examples of people using them to successfully create packet events: https://github.com/Hexeption/Nitro-Client/blob/master/src/main/java/uk/co/hexeption/client/mixin/mixins/MixinNetworkManager.java, https://github.com/cabaletta/baritone/blob/master/src/launch/java/baritone/launch/mixins/MixinNetworkManager.java, https://git.liquidbounce.net/CCBlueX/LiquidBase/blob/4b53d25e2893dbc5521d9a831a652b792f7803ea/src/main/java/net/ccbluex/liquidbase/injection/mixins/MixinNetworkManager.java, https://www.programcreek.com/java-api-examples/?code=ImpactDevelopment/ClientAPI/ClientAPI-master/src/main/java/clientapi/load/mixin/MixinNetworkManager.java, http://codingdict.com/sources/java/net.minecraft.network/53728.html