Paper/nms-patches/LoginListener.patch

--- a/net/minecraft/server/LoginListener.java
+++ b/net/minecraft/server/LoginListener.java
@@ -18,6 +18,12 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+// CraftBukkit start
+import org.bukkit.craftbukkit.util.Waitable;
+import org.bukkit.event.player.AsyncPlayerPreLoginEvent;
+import org.bukkit.event.player.PlayerPreLoginEvent;
+// CraftBukkit end
+
 public class LoginListener implements PacketLoginInListener, ITickable {
 
     private static final AtomicInteger b = new AtomicInteger(0);
@@ -32,6 +38,7 @@
     private final String j;
     private SecretKey loginKey;
     private EntityPlayer l;
+    public String hostname = ""; // CraftBukkit - add field
 
     public LoginListener(MinecraftServer minecraftserver, NetworkManager networkmanager) {
         this.g = LoginListener.EnumProtocolState.HELLO;
@@ -60,6 +67,20 @@
 
     }
 
+    // CraftBukkit start
+    @Deprecated
+    public void disconnect(String s) {
+        try {
+            IChatBaseComponent ichatbasecomponent = new ChatComponentText(s);
+            LoginListener.c.info("Disconnecting {}: {}", this.c(), s);
+            this.networkManager.sendPacket(new PacketLoginOutDisconnect(ichatbasecomponent));
+            this.networkManager.close(ichatbasecomponent);
+        } catch (Exception exception) {
+            LoginListener.c.error("Error whilst disconnecting player", exception);
+        }
+    }
+    // CraftBukkit end
+
     public void disconnect(IChatBaseComponent ichatbasecomponent) {
         try {
             LoginListener.c.info("Disconnecting {}: {}", this.c(), ichatbasecomponent.getString());
@@ -76,10 +97,12 @@
             this.i = this.a(this.i);
         }
 
-        IChatBaseComponent ichatbasecomponent = this.server.getPlayerList().attemptLogin(this.networkManager.getSocketAddress(), this.i);
+        // CraftBukkit start - fire PlayerLoginEvent
+        EntityPlayer s = this.server.getPlayerList().attemptLogin(this, this.i, hostname);
 
-        if (ichatbasecomponent != null) {
-            this.disconnect(ichatbasecomponent);
+        if (s == null) {
+            // this.disconnect(ichatbasecomponent);
+            // CraftBukkit end
         } else {
             this.g = LoginListener.EnumProtocolState.ACCEPTED;
             if (this.server.aw() >= 0 && !this.networkManager.isLocal()) {
@@ -93,9 +116,9 @@
 
             if (entityplayer != null) {
                 this.g = LoginListener.EnumProtocolState.DELAY_ACCEPT;
-                this.l = this.server.getPlayerList().processLogin(this.i);
+                this.l = this.server.getPlayerList().processLogin(this.i, s); // CraftBukkit - add player reference
             } else {
-                this.server.getPlayerList().a(this.networkManager, this.server.getPlayerList().processLogin(this.i));
+                this.server.getPlayerList().a(this.networkManager, this.server.getPlayerList().processLogin(this.i, s)); // CraftBukkit - add player reference
             }
         }
 
@@ -140,6 +163,43 @@
 
                         LoginListener.this.i = LoginListener.this.server.ap().hasJoinedServer(new GameProfile((UUID) null, gameprofile.getName()), s, this.a());
                         if (LoginListener.this.i != null) {
+                            // CraftBukkit start - fire PlayerPreLoginEvent
+                            if (!networkManager.isConnected()) {
+                                return;
+                            }
+
+                            String playerName = i.getName();
+                            java.net.InetAddress address = ((java.net.InetSocketAddress) networkManager.getSocketAddress()).getAddress();
+                            java.util.UUID uniqueId = i.getId();
+                            final org.bukkit.craftbukkit.CraftServer server = LoginListener.this.server.server;
+
+                            AsyncPlayerPreLoginEvent asyncEvent = new AsyncPlayerPreLoginEvent(playerName, address, uniqueId);
+                            server.getPluginManager().callEvent(asyncEvent);
+
+                            if (PlayerPreLoginEvent.getHandlerList().getRegisteredListeners().length != 0) {
+                                final PlayerPreLoginEvent event = new PlayerPreLoginEvent(playerName, address, uniqueId);
+                                if (asyncEvent.getResult() != PlayerPreLoginEvent.Result.ALLOWED) {
+                                    event.disallow(asyncEvent.getResult(), asyncEvent.getKickMessage());
+                                }
+                                Waitable<PlayerPreLoginEvent.Result> waitable = new Waitable<PlayerPreLoginEvent.Result>() {
+                                    @Override
+                                    protected PlayerPreLoginEvent.Result evaluate() {
+                                        server.getPluginManager().callEvent(event);
+                                        return event.getResult();
+                                    }};
+
+                                LoginListener.this.server.processQueue.add(waitable);
+                                if (waitable.get() != PlayerPreLoginEvent.Result.ALLOWED) {
+                                    disconnect(event.getKickMessage());
+                                    return;
+                                }
+                            } else {
+                                if (asyncEvent.getLoginResult() != AsyncPlayerPreLoginEvent.Result.ALLOWED) {
+                                    disconnect(asyncEvent.getKickMessage());
+                                    return;
+                                }
+                            }
+                            // CraftBukkit end
                             LoginListener.c.info("UUID of player {} is {}", LoginListener.this.i.getName(), LoginListener.this.i.getId());
                             LoginListener.this.g = LoginListener.EnumProtocolState.READY_TO_ACCEPT;
                         } else if (LoginListener.this.server.H()) {
@@ -159,6 +219,11 @@
                             LoginListener.this.disconnect(new ChatMessage("multiplayer.disconnect.authservers_down", new Object[0]));
                             LoginListener.c.error("Couldn't verify username because servers are unavailable");
                         }
+                        // CraftBukkit start - catch all exceptions
+                    } catch (Exception exception) {
+                        disconnect("Failed to verify username!");
+                        server.server.getLogger().log(java.util.logging.Level.WARNING, "Exception verifying " + gameprofile.getName(), exception);
+                        // CraftBukkit end
                     }
 
                 }