diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..9eab85a
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,8 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 4
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d17c514
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,31 @@
+# Maven
+target/
+dependency-reduced-pom.xml
+
+# Windows
+Thumbs.db
+[Dd]esktop.ini
+*.lnk
+
+# macOS
+.DS_Store
+
+# VS Code
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+*.code-workspace
+.history/
+
+# Eclipse JDT
+.settings/
+.metadata
+.project
+.classpath
+.factorypath
+
+# IDEA
+.idea/
+*.iws
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..29a9ac5
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,17 @@
+{
+ "files.exclude": {
+ "**/.classpath": true,
+ "**/.project": true,
+ "**/.settings": true,
+ "**/.factorypath": true
+ },
+ "java.configuration.updateBuildConfiguration": "automatic",
+ "json.schemas": [
+ {
+ "fileMatch": [
+ "**/plugin.yml"
+ ],
+ "url": "https://json.schemastore.org/bungee-plugin"
+ }
+ ]
+}
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..0a04128
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,165 @@
+ GNU LESSER GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc.
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+ This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+ 0. Additional Definitions.
+
+ As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+ "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+ An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
+of using an interface provided by the Library.
+
+ A "Combined Work" is a work produced by combining or linking an
+Application with the Library. The particular version of the Library
+with which the Combined Work was made is also called the "Linked
+Version".
+
+ The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+ The "Corresponding Application Code" for a Combined Work means the
+object code and/or source code for the Application, including any data
+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+ 1. Exception to Section 3 of the GNU GPL.
+
+ You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
+
+ 2. Conveying Modified Versions.
+
+ If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+ a) under this License, provided that you make a good faith effort to
+ ensure that, in the event an Application does not supply the
+ function or data, the facility still operates, and performs
+ whatever part of its purpose remains meaningful, or
+
+ b) under the GNU GPL, with none of the additional permissions of
+ this License applicable to that copy.
+
+ 3. Object Code Incorporating Material from Library Header Files.
+
+ The object code form of an Application may incorporate material from
+a header file that is part of the Library. You may convey such object
+code under terms of your choice, provided that, if the incorporated
+material is not limited to numerical parameters, data structure
+layouts and accessors, or small macros, inline functions and templates
+(ten or fewer lines in length), you do both of the following:
+
+ a) Give prominent notice with each copy of the object code that the
+ Library is used in it and that the Library and its use are
+ covered by this License.
+
+ b) Accompany the object code with a copy of the GNU GPL and this license
+ document.
+
+ 4. Combined Works.
+
+ You may convey a Combined Work under terms of your choice that,
+taken together, effectively do not restrict modification of the
+portions of the Library contained in the Combined Work and reverse
+engineering for debugging such modifications, if you also do each of
+the following:
+
+ a) Give prominent notice with each copy of the Combined Work that
+ the Library is used in it and that the Library and its use are
+ covered by this License.
+
+ b) Accompany the Combined Work with a copy of the GNU GPL and this license
+ document.
+
+ c) For a Combined Work that displays copyright notices during
+ execution, include the copyright notice for the Library among
+ these notices, as well as a reference directing the user to the
+ copies of the GNU GPL and this license document.
+
+ d) Do one of the following:
+
+ 0) Convey the Minimal Corresponding Source under the terms of this
+ License, and the Corresponding Application Code in a form
+ suitable for, and under terms that permit, the user to
+ recombine or relink the Application with a modified version of
+ the Linked Version to produce a modified Combined Work, in the
+ manner specified by section 6 of the GNU GPL for conveying
+ Corresponding Source.
+
+ 1) Use a suitable shared library mechanism for linking with the
+ Library. A suitable mechanism is one that (a) uses at run time
+ a copy of the Library already present on the user's computer
+ system, and (b) will operate properly with a modified version
+ of the Library that is interface-compatible with the Linked
+ Version.
+
+ e) Provide Installation Information, but only if you would otherwise
+ be required to provide such information under section 6 of the
+ GNU GPL, and only to the extent that such information is
+ necessary to install and execute a modified version of the
+ Combined Work produced by recombining or relinking the
+ Application with a modified version of the Linked Version. (If
+ you use option 4d0, the Installation Information must accompany
+ the Minimal Corresponding Source and Corresponding Application
+ Code. If you use option 4d1, you must provide the Installation
+ Information in the manner specified by section 6 of the GNU GPL
+ for conveying Corresponding Source.)
+
+ 5. Combined Libraries.
+
+ You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+ a) Accompany the combined library with a copy of the same work based
+ on the Library, uncombined with any other library facilities,
+ conveyed under the terms of this License.
+
+ b) Give prominent notice with the combined library that part of it
+ is a work based on the Library, and explaining where to find the
+ accompanying uncombined form of the same work.
+
+ 6. Revised Versions of the GNU Lesser General Public License.
+
+ The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+ Each version is given a distinguishing version number. If the
+Library as you received it specifies that a certain numbered version
+of the GNU Lesser General Public License "or any later version"
+applies to it, you have the option of following the terms and
+conditions either of that published version or of any later version
+published by the Free Software Foundation. If the Library as you
+received it does not specify a version number of the GNU Lesser
+General Public License, you may choose any version of the GNU Lesser
+General Public License ever published by the Free Software Foundation.
+
+ If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
+apply, that proxy's public statement of acceptance of any version is
+permanent authorization for you to choose that version for the
+Library.
diff --git a/pom.xml b/pom.xml
new file mode 100644
index 0000000..ab6f109
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,51 @@
+
+
+ 4.0.0
+
+ net.andylizi
+ haproxy-detector
+ 1.1
+ jar
+
+ HAProxyDetector
+
+
+ UTF-8
+ 1.8
+ 1.8
+
+
+
+ clean package
+
+
+ src/main/resources
+ true
+
+
+
+
+
+
+ sonatype-oss-repo
+ https://oss.sonatype.org/content/groups/public/
+
+
+
+
+
+ net.md-5
+ bungeecord-api
+ 1.16-R0.3
+ provided
+
+
+ io.netty
+ netty-codec-haproxy
+ 4.1.49.Final
+ provided
+
+
+
diff --git a/src/main/java/net/andylizi/haproxydetector/HAProxyDetector.java b/src/main/java/net/andylizi/haproxydetector/HAProxyDetector.java
new file mode 100644
index 0000000..25f12f1
--- /dev/null
+++ b/src/main/java/net/andylizi/haproxydetector/HAProxyDetector.java
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2020 Andy Li
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation, either version 3 of the License, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Lesser Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see .
+*/
+package net.andylizi.haproxydetector;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInitializer;
+import io.netty.handler.codec.ByteToMessageDecoder;
+import io.netty.handler.codec.ProtocolDetectionResult;
+import io.netty.handler.codec.haproxy.HAProxyMessageDecoder;
+import io.netty.handler.codec.haproxy.HAProxyProtocolVersion;
+import net.md_5.bungee.api.plugin.Plugin;
+
+public final class HAProxyDetector extends Plugin {
+ static Logger logger;
+
+ Field serverChildField;
+ ChannelInitializer originalChildInitializer;
+
+ @Override
+ public void onLoad() {
+ logger = getLogger();
+ }
+
+ @Override
+ @SuppressWarnings("unchecked")
+ public void onEnable() {
+ try {
+ Class pipelineUtilsClass = Class.forName("net.md_5.bungee.netty.PipelineUtils", true,
+ Thread.currentThread().getContextClassLoader());
+
+ serverChildField = pipelineUtilsClass.getField("SERVER_CHILD");
+ serverChildField.setAccessible(true);
+
+ Field modifiersField = Field.class.getDeclaredField("modifiers");
+ modifiersField.setAccessible(true);
+ modifiersField.setInt(serverChildField, serverChildField.getModifiers() & ~Modifier.FINAL);
+
+ originalChildInitializer = (ChannelInitializer) serverChildField.get(null);
+ serverChildField.set(null, new HAProxyDetectorInitializer(originalChildInitializer));
+ } catch (ReflectiveOperationException e) {
+ sneakyThrow(e);
+ return;
+ }
+ }
+
+ @Override
+ public void onDisable() {
+ if (serverChildField != null && originalChildInitializer != null) {
+ try {
+ serverChildField.set(null, originalChildInitializer);
+ } catch (ReflectiveOperationException ignored) {
+ }
+ }
+ }
+
+ static class HAProxyDetectorInitializer extends ChannelInitializer {
+ static MethodHandle initChannelHandle;
+
+ static {
+ try {
+ Method m = ChannelInitializer.class.getDeclaredMethod("initChannel", Channel.class);
+ m.setAccessible(true);
+ initChannelHandle = MethodHandles.lookup().unreflect(m);
+ } catch (ReflectiveOperationException e) {
+ sneakyThrow(e);
+ }
+ }
+
+ private final MethodHandle delegateInitHandle;
+
+ public HAProxyDetectorInitializer(ChannelInitializer delegateInitializer) {
+ delegateInitHandle = initChannelHandle.bindTo(delegateInitializer);
+ }
+
+ @Override
+ public void initChannel(C ch) throws Exception {
+ try {
+ delegateInitHandle.invoke(ch);
+ } catch (Throwable e) {
+ sneakyThrow(e);
+ return;
+ }
+
+ if (!ch.isOpen())
+ return;
+
+ HAProxyDetectorHandler detectorHandler = new HAProxyDetectorHandler();
+ try {
+ ch.pipeline().replace("haproxy-decoder", "haproxy-detector", detectorHandler);
+ } catch (NoSuchElementException e) {
+ try {
+ ch.pipeline().replace(HAProxyMessageDecoder.class, "haproxy-detector", detectorHandler);
+ } catch (NoSuchElementException e1) {
+ throw new RuntimeException("HAProxy support not enabled", e1);
+ }
+ } catch (IllegalArgumentException ignored) {
+ // detector already exists
+ }
+ }
+ }
+
+ static class HAProxyDetectorHandler extends ByteToMessageDecoder {
+ {
+ setSingleDecode(true);
+ }
+
+ @Override
+ public void decode(ChannelHandlerContext ctx, ByteBuf in, List