valence/packet_inspector

What's This?

The packet inspector is a very simple Minecraft proxy for viewing the contents of packets as they are sent/received. It uses Valence's protocol facilities to print packet contents. This was made for three purposes:

• Check that packets between Valence and client are matching your expectations.
• Check that packets between vanilla server and client are parsed correctly by Valence.
• Understand how the protocol works between the vanilla server and client.

Usage

First, start a server

cargo r -r --example conway

In a separate terminal, start the packet inspector.

cargo r -r -p packet_inspector -- 127.0.0.1:25566 127.0.0.1:25565

The client must connect to localhost:25566. You should see the packets in stdout.

The third argument to the packet inspector is an optional regular expression compatible with the regex crate. Packets with names that match the regex are printed while those that don't are ignored. If the regex is not provided then the empty string is assumed and all packets are considered matching.

If you're only interested in packets Foo, Bar, and Baz, you can use a regex such as ^(Foo|Bar|Baz)$.

cargo r -r -p packet_inspector -- 127.0.0.1:25566 127.0.0.1:25565 '^(Foo|Bar|Baz)$'

Packets are printed to stdout while errors are printed to stderr. If you only want to see errors in your terminal, direct stdout elsewhere.

cargo r -r -p packet_inspector -- 127.0.0.1:25566 127.0.0.1:25565 > log.txt

Quick start with Vanilla Server via Docker

Start the server

docker run -e EULA=TRUE -e ONLINE_MODE=false -d -p 25565:25565 --name mc itzg/minecraft-server

View server logs

docker logs -f mc

Server Rcon

docker exec -i mc rcon-cli

In a separate terminal, start the packet inspector.

cargo r -r -p packet_inspector -- 127.0.0.1:25566 127.0.0.1:25565

Open Minecraft and connect to localhost:25566.

Clean up

docker stop mc
docker rm mc