valence/crates/packet_inspector
Ryan Johnson 0960ad7ead
Refactor valence_protocol (#253)
## Description

- Remove duplicate packet definitions by using `Cow`.
- Rename packets to match yarn mappings.
- Remove some top-level re-exports.
- Move every packet into its own module for consistency.
- Move packet-specific types from the `types` module into the
appropriate packet module.
- Remove internal use of `EncodePacket`/`DecodePacket` derives and move
packet identification to `packet_group`. This can be done because there
are no duplicate packets anymore.
- Simplify some events.

In a future PR I plan to clean things up further by properly bounding
packet data (to prevent DoS exploits) and fixing any remaining
inconsistencies with the game's packet definitions.

## Test Plan

Behavior of `valence_protocol` should be the same.

Steps:
1. Use the packet inspector against the vanilla server to ensure packet
behavior has not changed.
2. Run the examples.
3. Run `valence_stresser`.
2023-02-23 22:16:22 -08:00
..
src Refactor valence_protocol (#253) 2023-02-23 22:16:22 -08:00
Cargo.toml Colorise the inspector output based on S2C or C2S (#242) 2023-02-14 15:31:17 -08:00
README.md Update packet inspector README 2023-01-11 22:58:00 -08:00

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 -i and -e flags accept a regex to filter packets according to their name. The -i regex includes matching packets while the -e regex excludes matching packets.

For instance, if you only want to print the packets Foo, Bar, and Baz, you can use a regex such as ^(Foo|Bar|Baz)$ with the -i flag.

cargo r -r -p packet_inspector -- 127.0.0.1:25566 127.0.0.1:25565 -i '^(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