--- a/net/minecraft/server/network/ServerHandshakePacketListenerImpl.java
+++ b/net/minecraft/server/network/ServerHandshakePacketListenerImpl.java
@@ -14,9 +_,20 @@
 
 public class ServerHandshakePacketListenerImpl implements ServerHandshakePacketListener {
     private static final Component IGNORE_STATUS_REASON = Component.translatable("disconnect.ignoring_status_request");
+    // Spigot start
+    private static final com.google.gson.Gson gson = new com.google.gson.Gson();
+    static final java.util.regex.Pattern HOST_PATTERN = java.util.regex.Pattern.compile("[0-9a-f\\.:]{0,45}");
+    static final java.util.regex.Pattern PROP_PATTERN = java.util.regex.Pattern.compile("\\w{0,16}");
+    // Spigot end
+    // Paper start - Connection throttle
+    private static final java.util.Map<java.net.InetAddress, Long> throttleTracker = new java.util.HashMap<>();
+    private static int throttleCounter = 0;
+    // Paper end - Connection throttle
+    private static final boolean BYPASS_HOSTCHECK = Boolean.getBoolean("Paper.bypassHostCheck"); // Paper
     private final MinecraftServer server;
     private final Connection connection;
 
+
     public ServerHandshakePacketListenerImpl(MinecraftServer server, Connection connection) {
         this.server = server;
         this.connection = connection;
@@ -24,6 +_,7 @@
 
     @Override
     public void handleIntention(ClientIntentionPacket packet) {
+        this.connection.hostname = packet.hostName() + ":" + packet.port(); // CraftBukkit  - set hostname
         switch (packet.intention()) {
             case LOGIN:
                 this.beginLogin(packet, false);
@@ -50,22 +_,118 @@
             default:
                 throw new UnsupportedOperationException("Invalid intention " + packet.intention());
         }
+
+        // Paper start - NetworkClient implementation
+        this.connection.protocolVersion = packet.protocolVersion();
+        this.connection.virtualHost = com.destroystokyo.paper.network.PaperNetworkClient.prepareVirtualHost(packet.hostName(), packet.port());
+        // Paper end
     }
 
     private void beginLogin(ClientIntentionPacket packet, boolean transferred) {
         this.connection.setupOutboundProtocol(LoginProtocols.CLIENTBOUND);
+        // Paper start - Connection throttle
+        try {
+            final long connectionThrottle = this.server.server.getConnectionThrottle();
+            final boolean isUnixDomainSocket = this.connection.channel.localAddress() instanceof io.netty.channel.unix.DomainSocketAddress; // Paper - Unix domain socket support; the connection throttle is useless when you have a Unix domain socket
+            if (connectionThrottle > 0 && !isUnixDomainSocket && this.connection.getRemoteAddress() instanceof java.net.InetSocketAddress socketAddress && !socketAddress.isUnresolved() && !socketAddress.getAddress().isLoopbackAddress()) {
+                long currentTime = System.currentTimeMillis();
+                java.net.InetAddress address = socketAddress.getAddress();
+
+                synchronized (ServerHandshakePacketListenerImpl.throttleTracker) {
+                    if (ServerHandshakePacketListenerImpl.throttleTracker.containsKey(address) && currentTime - ServerHandshakePacketListenerImpl.throttleTracker.get(address) < connectionThrottle) {
+                        ServerHandshakePacketListenerImpl.throttleTracker.put(address, currentTime);
+                        Component chatmessage = io.papermc.paper.adventure.PaperAdventure.asVanilla(io.papermc.paper.configuration.GlobalConfiguration.get().messages.kick.connectionThrottle);
+                        this.connection.send(new ClientboundLoginDisconnectPacket(chatmessage));
+                        this.connection.disconnect(chatmessage);
+                        return;
+                    }
+
+                    ServerHandshakePacketListenerImpl.throttleTracker.put(address, currentTime);
+                    ServerHandshakePacketListenerImpl.throttleCounter++;
+                    if (ServerHandshakePacketListenerImpl.throttleCounter > 200) {
+                        ServerHandshakePacketListenerImpl.throttleCounter = 0;
+
+                        // Cleanup stale entries
+                        ServerHandshakePacketListenerImpl.throttleTracker.values().removeIf(time -> time > connectionThrottle);
+                    }
+                }
+            }
+        } catch (Throwable t) {
+            org.apache.logging.log4j.LogManager.getLogger().debug("Failed to check connection throttle", t);
+        }
+        // Paper end - Connection throttle
         if (packet.protocolVersion() != SharedConstants.getCurrentVersion().getProtocolVersion()) {
-            Component component;
-            if (packet.protocolVersion() < 754) {
-                component = Component.translatable("multiplayer.disconnect.outdated_client", SharedConstants.getCurrentVersion().getName());
+            net.kyori.adventure.text.Component adventureComponent; // Paper - Fix hex colors not working in some kick messages
+            if (packet.protocolVersion() < SharedConstants.getCurrentVersion().getProtocolVersion()) { // Spigot - SPIGOT-7546: Handle version check correctly for outdated client message
+                adventureComponent = net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer.legacySection().deserialize(java.text.MessageFormat.format(org.spigotmc.SpigotConfig.outdatedClientMessage.replaceAll("'", "''"), SharedConstants.getCurrentVersion().getName())); // Spigot // Paper - Fix hex colors not working in some kick messages
             } else {
-                component = Component.translatable("multiplayer.disconnect.incompatible", SharedConstants.getCurrentVersion().getName());
+                adventureComponent = net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer.legacySection().deserialize(java.text.MessageFormat.format(org.spigotmc.SpigotConfig.outdatedServerMessage.replaceAll("'", "''"), SharedConstants.getCurrentVersion().getName())); // Spigot // Paper - Fix hex colors not working in some kick messages
             }
+            Component component = io.papermc.paper.adventure.PaperAdventure.asVanilla(adventureComponent); // Paper - Fix hex colors not working in some kick messages
 
             this.connection.send(new ClientboundLoginDisconnectPacket(component));
             this.connection.disconnect(component);
         } else {
             this.connection.setupInboundProtocol(LoginProtocols.SERVERBOUND, new ServerLoginPacketListenerImpl(this.server, this.connection, transferred));
+            // Paper start - PlayerHandshakeEvent
+            boolean proxyLogicEnabled = org.spigotmc.SpigotConfig.bungee;
+            boolean handledByEvent = false;
+            // Try and handle the handshake through the event
+            if (com.destroystokyo.paper.event.player.PlayerHandshakeEvent.getHandlerList().getRegisteredListeners().length != 0) { // Hello? Can you hear me?
+                java.net.SocketAddress socketAddress = this.connection.address;
+                String hostnameOfRemote = socketAddress instanceof java.net.InetSocketAddress ? ((java.net.InetSocketAddress) socketAddress).getHostString() : java.net.InetAddress.getLoopbackAddress().getHostAddress();
+                com.destroystokyo.paper.event.player.PlayerHandshakeEvent event = new com.destroystokyo.paper.event.player.PlayerHandshakeEvent(packet.hostName(), hostnameOfRemote, !proxyLogicEnabled);
+                if (event.callEvent()) {
+                    // If we've failed somehow, let the client know so and go no further.
+                    if (event.isFailed()) {
+                        Component message = io.papermc.paper.adventure.PaperAdventure.asVanilla(event.failMessage());
+                        this.connection.send(new ClientboundLoginDisconnectPacket(message));
+                        this.connection.disconnect(message);
+                        return;
+                    }
+
+                    if (event.getServerHostname() != null) {
+                        // change hostname
+                        packet = new ClientIntentionPacket(
+                            packet.protocolVersion(),
+                            event.getServerHostname(),
+                            packet.port(),
+                            packet.intention()
+                        );
+                    }
+                    if (event.getSocketAddressHostname() != null) this.connection.address = new java.net.InetSocketAddress(event.getSocketAddressHostname(), socketAddress instanceof java.net.InetSocketAddress ? ((java.net.InetSocketAddress) socketAddress).getPort() : 0);
+                    this.connection.spoofedUUID = event.getUniqueId();
+                    this.connection.spoofedProfile = gson.fromJson(event.getPropertiesJson(), com.mojang.authlib.properties.Property[].class);
+                    handledByEvent = true; // Hooray, we did it!
+                }
+            }
+            // Paper end
+            // Spigot start
+            String[] split = packet.hostName().split("\00");
+            if (!handledByEvent && proxyLogicEnabled) { // Paper
+                // if (org.spigotmc.SpigotConfig.bungee) { // Paper - comment out, we check above!
+                if ((split.length == 3 || split.length == 4) && (ServerHandshakePacketListenerImpl.BYPASS_HOSTCHECK || ServerHandshakePacketListenerImpl.HOST_PATTERN.matcher(split[1]).matches())) { // Paper - Add bypass host check
+                    // Paper start - Unix domain socket support
+                    java.net.SocketAddress socketAddress = this.connection.getRemoteAddress();
+                    this.connection.hostname = split[0];
+                    this.connection.address = new java.net.InetSocketAddress(split[1], socketAddress instanceof java.net.InetSocketAddress ? ((java.net.InetSocketAddress) socketAddress).getPort() : 0);
+                    // Paper end - Unix domain socket support
+                    this.connection.spoofedUUID = com.mojang.util.UndashedUuid.fromStringLenient( split[2] );
+                } else {
+                    Component message = Component.literal("If you wish to use IP forwarding, please enable it in your BungeeCord config as well!");
+                    this.connection.send(new ClientboundLoginDisconnectPacket(message));
+                    this.connection.disconnect(message);
+                    return;
+                }
+                if (split.length == 4) {
+                    this.connection.spoofedProfile = ServerHandshakePacketListenerImpl.gson.fromJson(split[3], com.mojang.authlib.properties.Property[].class);
+                }
+            } else if ((split.length == 3 || split.length == 4) && (ServerHandshakePacketListenerImpl.HOST_PATTERN.matcher(split[1]).matches())) {
+                Component message = Component.literal("Unknown data in login hostname, did you forget to enable BungeeCord in spigot.yml?");
+                this.connection.send(new ClientboundLoginDisconnectPacket(message));
+                this.connection.disconnect(message);
+            }
+            // Spigot end
         }
     }
 
