ProtocolLib

ProtocolLib

Use 3.2.0 for Minecraft 1.7.2/1.6.4/1.6.2/1.5.2/1.4.7 and older

Certain tasks are impossible to perform with the standard Bukkit API, and may require working with and even modify Minecraft directly. A common technique is to modify incoming and outgoing packets, or inject custom packets into the stream. This is quite cumbersome to do, however, and most implementations will break as soon as a new version of Minecraft has been released, mostly due to obfuscation.

Critically, different plugins that use this approach may hook into the same classes, with unpredictable outcomes. More than often this causes plugins to crash, but it may also lead to more subtle bugs.

Up-to-date developer builds of this project can be acquired at my Jenkins server. These builds have not been approved by the BukkitDev staff. Use them at your own risk.

Support

Please create a ticket with as much information as possible if you experience a problem that has not already been reported. Comments with a huge stack trace will be deleted.

If you need help with the API, please use the developer support forum. If your question cannot be made public for whatever reason (including security bugs), send me a personal message instead.

For server operators

Just download ProtocolLib from the link above. It doesn't do anything on its own, it simply allows other plugins to function.

Examples

Source code for a bunch of example programs that use ProtocolLib can be found at this thread on the main support forum.

You may also be interested in PacketWrapper, a library that makes it possible to modify a packet without having to decompile the Minecraft source code.

Finally, for the more advanced users who want to use ProtocolLib if present, but still fall back on their own packet listening system, I recommend taking a look at this thread. I explain where and how to inject code into CraftBukkit in order to intercept sent and received packets yourself.

Maven repository

If you're using Maven, you'll be able to automatically download the JAR, JavaDoc and associated sources from the following repository:

<repositories>
  <repository>
    <id>comphenix-rep</id>
    <name>Comphenix Repository</name>
    <url>http://repo.comphenix.net/content/groups/public</url>
  </repository>
<!-- And so on -->
</repositories>

This repository contains ProtocolLib, TagHelper and BlockPatcher. You can add any of them as a dependency like so:

<dependencies>
  <dependency>
    <groupId>com.comphenix.protocol</groupId>
    <artifactId>ProtocolLib</artifactId>
    <version>3.1.0</version>
  </dependency>
</dependencies>

Commands

Protocol

Main administrative command. Supports the following sub-commands:

  • config: Reload the configuration file.
  • check: Check for new versions on BukkitDev.
  • update: Check for new versions and automatically download the JAR. The server must be restarted for this to take effect.
  • timings: Toggle measuring the amount of CPU time spent by each plugin. See here for more information.
  • listeners: Display what plugins are using ProtocolLib, and the packet types they are intercepting.

All of these commands require the permission protocol.admin.

Example:

/protocol update

Packet

Add or remove a debug packet listener. This is useful for plugin authors who just wants to see when a packet is sent, and with what content.

Sub commands:

  • add: Add a packet listener with a given packet ID.
  • remove: Remove one or every packet listener with the given packet IDs.
  • names: Print the name of every given packet ID.

Parameters (in order):

  1. Connection side: Either client or server.
  2. Multiple ID ranges: Can be a single packet ID like 14, or a range like 10 - 15. Defaults to 0 - 255 if not specified.
  3. Detailed: If TRUE, prints the full packet content.

Example:

/packet add client 10-13 true

Remove all listeners:

/packet remove client
/packet remove server

Note that this command should rarely be used on a production server. Listening to too many packets may crash the server.

Filter

The filter system (introduced in 2.4.1) uses the built in JavaScript interpreter in JVM 6 (Rhino) to extend the packet command with filtering capabilities - it is now possible to, say, only print entity metadata packet events (packet add server 40) for a given entity ID:

> packet add server 40 true
Added listener ListeningWhitelist{priority=MONITOR, packets=[40]}
> filter add entity_filter 40
Enter filter program ('}' to complete or CANCEL):
function(event, packet) {
>   return packet.a == 1000; 
>}
Added filter entity_filter.

This should be much more convenient than having to compile a test plugin and reload the whole server. Note that this feature is disabled by default for security reasons. To enable it, add "debug: true" to config.yml.

Configuration

A small set of configuration options are available:

Global section

OptionDefault

Description

auto updater.notifytrueInform any player with the permission protocol.info when a new version of ProtocolLib is out.
auto updater.downloadtrueAutomatically download and install the newest version of ProtocolLib. The installation will take effect when the server restarts.
auto updater.delay43200The number of seconds between each check for a new update.
auto updater.last0This simply records the last time (in seconds since 01.01.1970) an update check was performed. Set it to 0 to force a new update check.
metricstrueIf TRUE, ProtocolLib will publish anonymous usage data to mcstats.org. Set it to FALSE to opt-out.
background compilertrueIf TRUE, ProtocolLib will try and improve performance by replacing reflection with compiled code on-the-fly.
ignore version checkNoneForce ProtocolLib to start for a specified Minecraft version, even if it is incompatible.
suppressed reportsNoneIf any error or warning report is present in this list, they will not appear in the console or the log.

For more information, take a look at the default configuration file.

Tutorial for developers

See this page for more information.

Compatibility

One of the main goals of this project was to achieve maximum compatibility with CraftBukkit. And the end result is quite good - in tests I successfully ran an unmodified ProtocolLib on CraftBukkit 1.8.0, and it should be resilient against future changes. It's likely that I won't have to update ProtocolLib for anything but bug and performance fixes.

How is this possible? It all comes down to reflection in the end. Essentially, no name is hard coded - every field, method and class is deduced by looking at field types, package names or parameter types. It's remarkably consistent across different versions.

Plugins that appear to be compatible

Plugins known to be compatible

  • SpoutPlugin

Plugins using ProtocolLib

Inactive projects

Please let me know if you want me to add your plugin to this list. :)

Privacy

This plugin uses MCStats to generate and publish anonymous aggregate usage statistics, but you can easily opt-out by setting metrics in config.yml to false.

If enabled, the following is sent every ten minutes:

  • Metrics revision version (currently 6).
  • Server's GUID
  • Players currently online (not max player count)
  • Server version string (the same version string you see in /version)
  • Current version of ProtocolLib
  • The name of every plugin that registers a packet listener in ProtocolLib.

Acknowledgements

I would like to thank everyone who has donated to ProtocoLib. I really appreciate it. :)

Donate

Statistics

ProtocolLib Statistics

Note: Create a ticket if you're having problems. Don't post stack traces in the comments.

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  • Avatar of PillageCraft PillageCraft Apr 17, 2014 at 06:47 UTC - 0 likes

    @TNTUP: Go

    I'm getting this error as well. I believe it may be caused by ProtocolLib. I am running Spigot build #1383 in conjunction with ProtocolLib 3.2.0.

  • Avatar of TNTUP TNTUP Apr 17, 2014 at 04:44 UTC - 0 likes

    Does ProtocolLib related to this kind of error?

    Internal Exception: net.minecraft.util.io.netty.handler.codec.EncoderException: java.lang.RuntimeException: An internal error occured.

    BFAK:95066,dd3bd97af6e0c8de224582d02370f079170eea468d01c5afc6a4b2b0119a2840

  • Avatar of Jleeevinnn Jleeevinnn Apr 16, 2014 at 23:56 UTC - 0 likes

    Any working builds for 1.7.8?

    My server is a full production server running on 1.7.8 with successful UUID conversion.

  • Avatar of aadnk aadnk Apr 16, 2014 at 00:50 UTC - 1 like

    @libraryaddict: Go

    Hm - I think I've found a fix. Try build #240.

    @NolifeM: Go

    There are fundamental issues in MCPC-Plus I can't work around, so I've temporarily suspended work on making ProtocolLib compatible. I may try again in the future.

    @CrystalxNeth: Go

    That error can only be caused by an old version of TagAPI, so I recommend upgrading.

    Last edited Apr 16, 2014 by aadnk
  • Avatar of CrystalxNeth CrystalxNeth Apr 15, 2014 at 23:39 UTC - 0 likes

    When using the latest snapshot from April 14th, I get this error frequently http://pastebin.com/NfPugdu7, where I think the cause of the error may be is highlighted in the paste. It never happens when theres one player online, and seems to happen most often when a player leaves/joins. Rarely the console will get spammed by it as well. I am using PacketWrapper fyi, so that may have something to do with it. Before 1.7 this never happened, and in the beginning of the 1.7 updates this would happen frequently until there was an update which fixed it, now after upgrading to 1.7.8+ it came back.

  • Avatar of libraryaddict libraryaddict Apr 14, 2014 at 15:27 UTC - 0 likes

    http://hastebin.com/lupovusiwa.avrasm

    This occurs when I use packetEvent.setPacket(packetEvent.getPacket().deepClone());

    BFAK:libraryaddict,75154,c9bc87ad599337d3271d3cb02958adc594ab27bb05cc09136881ff0723c8fcb4

  • Avatar of NolifeM NolifeM Apr 14, 2014 at 08:36 UTC - 0 likes

    Great Plugin! It works fine on spogit server 1.7.2.what a pity it did not work on MCPC1.7.2...

  • Avatar of aadnk aadnk Apr 12, 2014 at 22:10 UTC - 0 likes

    @dermarionator: Go

    That's unrelated to ProtocolLib though. You should report any errors you get due to other plugins in their respective plugin pages (here, for NoLagg).

    @Iwitrag: Go

    Only partially. I had to push a new version (3.3.1-SNAPSHOT) on the Jenkins server (build #237) to fix a couple of issues with the NBT library and server ping wrapper.

    @Burglory: Go

    Sounds like you actually want these falling blocks to stay on the server side. I recommend using World.spawnFallingBlock(Location, int, byte) instead.

    That way, you don't have to implement the "turning into blocks" feature yourself, as its already vanilla behavior. It should also take care of entities that fall into the void.

  • Avatar of dermarionator dermarionator Apr 11, 2014 at 20:42 UTC - 0 likes

    The is a Problem with Commandhelper and Nolagg

    http://pastebin.com/UnguvDSz

    Last edited Apr 11, 2014 by dermarionator

    Logo

  • Avatar of Iwitrag Iwitrag Apr 11, 2014 at 17:24 UTC - 0 likes
    Hello, is it compatible with 1.7.5? When I start server I get this: [19:05:33] [Server thread/WARN]: [ProtocolLib] Version (MC: 1.7.5) has not yet been tested! Proceed with caution.

Facts

Date created
Oct 05, 2012
Category
Last update
Jan 29, 2014
Development stage
Release
Language
  • enUS
License
GNU General Public License version 2 (GPLv2)
Curse link
ProtocolLib
Downloads
646,680
Recent files

Authors