PaperMC/Spigot-Server-Patches/0251-Call-PaperServerListPingEvent-for-legacy-pings.patch

From 23918472ceeac090b7d1dc1cacc894ca722fc0a7 Mon Sep 17 00:00:00 2001
From: Minecrell <minecrell@minecrell.net>
Date: Wed, 11 Oct 2017 19:30:51 +0200
Subject: [PATCH] Call PaperServerListPingEvent for legacy pings


diff --git a/src/main/java/com/destroystokyo/paper/network/PaperLegacyStatusClient.java b/src/main/java/com/destroystokyo/paper/network/PaperLegacyStatusClient.java
new file mode 100644
index 0000000000..74c012fd40
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/network/PaperLegacyStatusClient.java
@@ -0,0 +1,73 @@
+package com.destroystokyo.paper.network;
+
+import com.destroystokyo.paper.event.server.PaperServerListPingEvent;
+import net.minecraft.server.MinecraftServer;
+import org.apache.commons.lang3.StringUtils;
+import org.bukkit.ChatColor;
+
+import java.net.InetSocketAddress;
+
+import javax.annotation.Nullable;
+
+public final class PaperLegacyStatusClient implements StatusClient {
+
+    private final InetSocketAddress address;
+    private final int protocolVersion;
+    @Nullable private final InetSocketAddress virtualHost;
+
+    private PaperLegacyStatusClient(InetSocketAddress address, int protocolVersion, @Nullable InetSocketAddress virtualHost) {
+        this.address = address;
+        this.protocolVersion = protocolVersion;
+        this.virtualHost = virtualHost;
+    }
+
+    @Override
+    public InetSocketAddress getAddress() {
+        return this.address;
+    }
+
+    @Override
+    public int getProtocolVersion() {
+        return this.protocolVersion;
+    }
+
+    @Nullable
+    @Override
+    public InetSocketAddress getVirtualHost() {
+        return this.virtualHost;
+    }
+
+    @Override
+    public boolean isLegacy() {
+        return true;
+    }
+
+    public static PaperServerListPingEvent processRequest(MinecraftServer server,
+            InetSocketAddress address, int protocolVersion, @Nullable InetSocketAddress virtualHost) {
+
+        PaperServerListPingEvent event =  new PaperServerListPingEventImpl(server,
+                new PaperLegacyStatusClient(address, protocolVersion, virtualHost), Byte.MAX_VALUE, null);
+        server.server.getPluginManager().callEvent(event);
+
+        if (event.isCancelled()) {
+            return null;
+        }
+
+        return event;
+    }
+
+    public static String getMotd(PaperServerListPingEvent event) {
+        return getFirstLine(event.getMotd());
+    }
+
+    public static String getUnformattedMotd(PaperServerListPingEvent event) {
+        // Strip color codes and all other occurrences of the color char (because it's used as delimiter)
+        return getFirstLine(StringUtils.remove(ChatColor.stripColor(event.getMotd()), ChatColor.COLOR_CHAR));
+    }
+
+    private static String getFirstLine(String s) {
+        int pos = s.indexOf('\n');
+        return pos >= 0 ? s.substring(0, pos) : s;
+    }
+
+}
diff --git a/src/main/java/net/minecraft/server/LegacyPingHandler.java b/src/main/java/net/minecraft/server/LegacyPingHandler.java
index 07c53f5057..91acfceec8 100644
--- a/src/main/java/net/minecraft/server/LegacyPingHandler.java
+++ b/src/main/java/net/minecraft/server/LegacyPingHandler.java
@@ -9,6 +9,7 @@ import java.net.InetSocketAddress;
 import java.nio.charset.StandardCharsets;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import com.destroystokyo.paper.network.PaperLegacyStatusClient; // Paper
 
 public class LegacyPingHandler extends ChannelInboundHandlerAdapter {
 
@@ -44,11 +45,20 @@ public class LegacyPingHandler extends ChannelInboundHandlerAdapter {
             MinecraftServer minecraftserver = this.b.d();
             int i = bytebuf.readableBytes();
             String s;
+            com.destroystokyo.paper.event.server.PaperServerListPingEvent event; // Paper
 
             switch (i) {
             case 0:
                 LegacyPingHandler.a.debug("Ping: (<1.3.x) from {}:{}", inetsocketaddress.getAddress(), Integer.valueOf(inetsocketaddress.getPort()));
-                s = String.format("%s\u00a7%d\u00a7%d", new Object[] { minecraftserver.getMotd(), Integer.valueOf(minecraftserver.A()), Integer.valueOf(minecraftserver.B())});
+                // Paper start - Call PaperServerListPingEvent and use results
+                event = PaperLegacyStatusClient.processRequest(minecraftserver, inetsocketaddress, 39, null);
+                if (event == null) {
+                    channelhandlercontext.close();
+                    break;
+                }
+                s = String.format("%s\u00a7%d\u00a7%d", PaperLegacyStatusClient.getUnformattedMotd(event), event.getNumPlayers(), event.getMaxPlayers());
+
+                // Paper end
                 this.a(channelhandlercontext, this.a(s));
                 break;
 
@@ -57,8 +67,15 @@ public class LegacyPingHandler extends ChannelInboundHandlerAdapter {
                     return;
                 }
 
-                LegacyPingHandler.a.debug("Ping: (1.4-1.5.x) from {}:{}", inetsocketaddress.getAddress(), Integer.valueOf(inetsocketaddress.getPort()));
-                s = String.format("\u00a71\u0000%d\u0000%s\u0000%s\u0000%d\u0000%d", new Object[] { Integer.valueOf(127), minecraftserver.getVersion(), minecraftserver.getMotd(), Integer.valueOf(minecraftserver.A()), Integer.valueOf(minecraftserver.B())});
+                // Paper start - Call PaperServerListPingEvent and use results
+                event = PaperLegacyStatusClient.processRequest(minecraftserver, inetsocketaddress, 61, null);
+                if (event == null) {
+                    channelhandlercontext.close();
+                    break;
+                }
+                s = String.format("\u00a71\u0000%d\u0000%s\u0000%s\u0000%d\u0000%d", event.getProtocolVersion(), event.getVersion(),
+                        PaperLegacyStatusClient.getMotd(event), event.getNumPlayers(), event.getMaxPlayers());
+                // Paper end
                 this.a(channelhandlercontext, this.a(s));
                 break;
 
@@ -170,8 +187,16 @@ public class LegacyPingHandler extends ChannelInboundHandlerAdapter {
 
         a.debug("Ping: (1.6) from {}", ctx.channel().remoteAddress());
 
-        String response = String.format("\u00a71\u0000%d\u0000%s\u0000%s\u0000%d\u0000%d",
-                Byte.MAX_VALUE, server.getVersion(), server.getMotd(), server.getPlayerCount(), server.getMaxPlayers());
+        InetSocketAddress virtualHost = com.destroystokyo.paper.network.PaperNetworkClient.prepareVirtualHost(host, port);
+        com.destroystokyo.paper.event.server.PaperServerListPingEvent event = PaperLegacyStatusClient.processRequest(
+                server, (InetSocketAddress) ctx.channel().remoteAddress(), protocolVersion, virtualHost);
+        if (event == null) {
+            ctx.close();
+            return;
+        }
+
+        String response = String.format("\u00a71\u0000%d\u0000%s\u0000%s\u0000%d\u0000%d", event.getProtocolVersion(), event.getVersion(),
+                PaperLegacyStatusClient.getMotd(event), event.getNumPlayers(), event.getMaxPlayers());
         this.a(ctx, this.a(response));
     }
 
-- 
2.18.0