RCON
Rcon is a protocol introduced in 1.9pre4 for the purpose of remote administration of a server.
Contents
Server Config
enable-rcon=true rcon.password=<your password>
Packet Format
Integers are little-endian, in contrast with the Beta protocol.
You should generate a new packet ID for every packet you send. This allows you to match up incoming packets (responses) with what you sent.
In the event of an auth failure (i.e. your login is incorrect, or you're trying to send commands without first logging in), packet ID will be set to -1
| Field name | Field Type | Notes |
|---|---|---|
| Length | int | Length of remainder of packet |
| Packet ID | int | Client-generated token |
| Packet Type | int | 3 for login, 2 to run a command
|
| Payload | byte[] | ASCII text |
| 2-byte pad | byte, byte | Two null bytes |
Packets
3: Login
Outgoing payload: password.
If the server returns a packet with the same ID, auth was successful. If you get an ID of -1, auth failed (wrong password).
2: Command
Outgoing payload should be the command to run, e.g. time set 0
Incoming payload is the output of the command, though many commands return nothing, and there's no way of detecting unknown commands.
Implementation details
Maximum request length: 1460 (giving a max payload length of 1446)
Code exists in the notchian server to split large responses (>4096 bytes) into multiple smaller packets. However, the code that actually encodes each packet expects a max length of 1248, giving a max return payload length of 1234 bytes.
Example implementations
- https://github.com/barneygale/MCRcon (python, basic, synchronous)
