From 05f3042755ef48a84a34e431c27cb9eb75029d98 Mon Sep 17 00:00:00 2001
From: CraftBukkit/Spigot <noreply+git-craftbukkit@papermc.io>
Date: Fri, 25 Apr 2014 23:46:46 +0200
Subject: [PATCH] Fix race condition that could kill connections before they
 were initiated

Because NetworkManagers are registered before they get their channel in
channelActive, the ServerConnection would remove them sometimes because
it thought they were disconnected. This commit fixes this by introducing
a 'preparing' variable that is true while the NetworkManager is not
initialized. The ServerConnection does not remove NetworkManagers with
this flag.

By: Jonas Konrad <me@yawk.at>
---
 .../minecraft/network/Connection.java.patch   | 31 +++++++++++++++----
 .../ServerConnectionListener.java.patch       | 11 +++++++
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/paper-server/patches/sources/net/minecraft/network/Connection.java.patch b/paper-server/patches/sources/net/minecraft/network/Connection.java.patch
index 741945a0a9..75c2e579f8 100644
--- a/paper-server/patches/sources/net/minecraft/network/Connection.java.patch
+++ b/paper-server/patches/sources/net/minecraft/network/Connection.java.patch
@@ -1,17 +1,18 @@
 --- a/net/minecraft/network/Connection.java
 +++ b/net/minecraft/network/Connection.java
-@@ -96,6 +96,10 @@
+@@ -96,6 +96,11 @@
      private final Queue<Consumer<Connection>> pendingActions = Queues.newConcurrentLinkedQueue();
      public Channel channel;
      public SocketAddress address;
 +    // Spigot Start
 +    public java.util.UUID spoofedUUID;
 +    public com.mojang.authlib.properties.Property[] spoofedProfile;
++    public boolean preparing = true;
 +    // Spigot End
      @Nullable
      private volatile PacketListener disconnectListener;
      @Nullable
-@@ -114,6 +118,7 @@
+@@ -114,6 +119,7 @@
      private volatile DisconnectionDetails delayedDisconnect;
      @Nullable
      BandwidthDebugMonitor bandwidthDebugMonitor;
@@ -19,7 +20,17 @@
  
      public Connection(PacketFlow side) {
          this.receiving = side;
-@@ -176,6 +181,7 @@
+@@ -123,6 +129,9 @@
+         super.channelActive(channelhandlercontext);
+         this.channel = channelhandlercontext.channel();
+         this.address = this.channel.remoteAddress();
++        // Spigot Start
++        this.preparing = false;
++        // Spigot End
+         if (this.delayedDisconnect != null) {
+             this.disconnect(this.delayedDisconnect);
+         }
+@@ -176,6 +185,7 @@
  
              }
          }
@@ -27,7 +38,7 @@
      }
  
      protected void channelRead0(ChannelHandlerContext channelhandlercontext, Packet<?> packet) {
-@@ -205,7 +211,7 @@
+@@ -205,7 +215,7 @@
      }
  
      private static <T extends PacketListener> void genericsFtw(Packet<T> packet, PacketListener listener) {
@@ -36,7 +47,15 @@
      }
  
      private void validateListener(ProtocolInfo<?> state, PacketListener listener) {
-@@ -469,7 +475,7 @@
+@@ -464,12 +474,15 @@
+     }
+ 
+     public void disconnect(DisconnectionDetails disconnectionInfo) {
++        // Spigot Start
++        this.preparing = false;
++        // Spigot End
+         if (this.channel == null) {
+             this.delayedDisconnect = disconnectionInfo;
          }
  
          if (this.isConnected()) {
@@ -45,7 +64,7 @@
              this.disconnectionDetails = disconnectionInfo;
          }
  
-@@ -537,7 +543,7 @@
+@@ -537,7 +550,7 @@
      }
  
      public void configurePacketHandler(ChannelPipeline pipeline) {
diff --git a/paper-server/patches/sources/net/minecraft/server/network/ServerConnectionListener.java.patch b/paper-server/patches/sources/net/minecraft/server/network/ServerConnectionListener.java.patch
index 39649142ff..c04e76d0bd 100644
--- a/paper-server/patches/sources/net/minecraft/server/network/ServerConnectionListener.java.patch
+++ b/paper-server/patches/sources/net/minecraft/server/network/ServerConnectionListener.java.patch
@@ -43,3 +43,14 @@
              Iterator<Connection> iterator = this.connections.iterator();
  
              while (iterator.hasNext()) {
+@@ -176,6 +193,10 @@
+                             networkmanager.setReadOnly();
+                         }
+                     } else {
++                        // Spigot Start
++                        // Fix a race condition where a NetworkManager could be unregistered just before connection.
++                        if (networkmanager.preparing) continue;
++                        // Spigot End
+                         iterator.remove();
+                         networkmanager.handleDisconnection();
+                     }