Add the unversioned patches.

patches/net/minecraft/client/multiplayer/CommonListenerCookie.java.patch

@@ -0,0 +1,10 @@
+--- a/net/minecraft/client/multiplayer/CommonListenerCookie.java
++++ b/net/minecraft/client/multiplayer/CommonListenerCookie.java
+@@ -15,6 +15,7 @@
+    WorldSessionTelemetryManager telemetryManager,
+    RegistryAccess.Frozen receivedRegistries,
+    FeatureFlagSet enabledFeatures,
++   boolean isModdedConnection,
+    @Nullable String serverBrand,
+    @Nullable ServerData serverData,
+    @Nullable Screen postDisconnectScreen

patches/net/minecraft/network/ConnectionProtocol.java.patch

@@ -0,0 +1,135 @@
+--- a/net/minecraft/network/ConnectionProtocol.java
++++ b/net/minecraft/network/ConnectionProtocol.java
+@@ -3,6 +3,7 @@
+ import com.google.common.collect.Lists;
+ import com.google.common.collect.Maps;
+ import com.mojang.logging.LogUtils;
++import io.netty.channel.ChannelHandlerContext;
+ import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+ import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+ import it.unimi.dsi.fastutil.objects.Object2IntMap;
+@@ -12,6 +13,7 @@
+ import java.util.List;
+ import java.util.Map;
+ import java.util.Set;
++import java.util.function.BiFunction;
+ import java.util.function.Function;
+ import javax.annotation.Nullable;
+ import net.minecraft.Util;
+@@ -238,7 +240,7 @@
+                .addPacket(ClientboundContainerSetSlotPacket.class, ClientboundContainerSetSlotPacket::new)
+                .addPacket(ClientboundCooldownPacket.class, ClientboundCooldownPacket::new)
+                .addPacket(ClientboundCustomChatCompletionsPacket.class, ClientboundCustomChatCompletionsPacket::new)
+-               .addPacket(ClientboundCustomPayloadPacket.class, ClientboundCustomPayloadPacket::new)
++               .addContextualPacket(ClientboundCustomPayloadPacket.class, (buf, context) -> new ClientboundCustomPayloadPacket(buf, context, ConnectionProtocol.play()))
+                .addPacket(ClientboundDamageEventPacket.class, ClientboundDamageEventPacket::new)
+                .addPacket(ClientboundDeleteChatPacket.class, ClientboundDeleteChatPacket::new)
+                .addPacket(ClientboundDisconnectPacket.class, ClientboundDisconnectPacket::new)
+@@ -346,7 +348,7 @@
+                .addPacket(ServerboundContainerButtonClickPacket.class, ServerboundContainerButtonClickPacket::new)
+                .addPacket(ServerboundContainerClickPacket.class, ServerboundContainerClickPacket::new)
+                .addPacket(ServerboundContainerClosePacket.class, ServerboundContainerClosePacket::new)
+-               .addPacket(ServerboundCustomPayloadPacket.class, ServerboundCustomPayloadPacket::new)
++               .addContextualPacket(ServerboundCustomPayloadPacket.class, (buf, context) -> new ServerboundCustomPayloadPacket(buf, context, ConnectionProtocol.play()))
+                .addPacket(ServerboundEditBookPacket.class, ServerboundEditBookPacket::new)
+                .addPacket(ServerboundEntityTagQuery.class, ServerboundEntityTagQuery::new)
+                .addPacket(ServerboundInteractPacket.class, ServerboundInteractPacket::new)
+@@ -430,7 +432,7 @@
+          .addFlow(
+             PacketFlow.CLIENTBOUND,
+             new ConnectionProtocol.PacketSet<net.minecraft.network.protocol.configuration.ClientConfigurationPacketListener>()
+-               .addPacket(ClientboundCustomPayloadPacket.class, ClientboundCustomPayloadPacket::new)
++               .addContextualPacket(ClientboundCustomPayloadPacket.class, (buf, context) -> new ClientboundCustomPayloadPacket(buf, context, ConnectionProtocol.configuration()))
+                .addPacket(ClientboundDisconnectPacket.class, ClientboundDisconnectPacket::new)
+                .addPacket(ClientboundFinishConfigurationPacket.class, ClientboundFinishConfigurationPacket::new)
+                .addPacket(ClientboundKeepAlivePacket.class, ClientboundKeepAlivePacket::new)
+@@ -444,7 +446,7 @@
+             PacketFlow.SERVERBOUND,
+             new ConnectionProtocol.PacketSet<net.minecraft.network.protocol.configuration.ServerConfigurationPacketListener>()
+                .addPacket(ServerboundClientInformationPacket.class, ServerboundClientInformationPacket::new)
+-               .addPacket(ServerboundCustomPayloadPacket.class, ServerboundCustomPayloadPacket::new)
++               .addContextualPacket(ServerboundCustomPayloadPacket.class, (buf, context) -> new ServerboundCustomPayloadPacket(buf, context, ConnectionProtocol.play()))
+                .addPacket(ServerboundFinishConfigurationPacket.class, ServerboundFinishConfigurationPacket::new)
+                .addPacket(ServerboundKeepAlivePacket.class, ServerboundKeepAlivePacket::new)
+                .addPacket(ServerboundPongPacket.class, ServerboundPongPacket::new)
+@@ -456,6 +458,22 @@
+    private final String id;
+    private final Map<PacketFlow, ConnectionProtocol.CodecData<?>> flows;
+
++   private static ConnectionProtocol play() {
++        return PLAY;
++   }
++   
++   private static ConnectionProtocol configuration() {
++      return CONFIGURATION;
++   }
++   
++   public boolean isPlay() {
++      return this == PLAY;
++   }
++   
++   public boolean isConfiguration() {
++      return this == CONFIGURATION;
++   }
++   
+    private static ConnectionProtocol.ProtocolBuilder protocol() {
+       return new ConnectionProtocol.ProtocolBuilder();
+    }
+@@ -514,8 +532,8 @@
+       }
+
+       @Nullable
+-      public Packet<?> createPacket(int p_294972_, FriendlyByteBuf p_296217_) {
+-         return this.packetSet.createPacket(p_294972_, p_296217_);
++      public Packet<?> createPacket(int p_294972_, FriendlyByteBuf p_296217_, ChannelHandlerContext p_130535_) {
++         return this.packetSet.createPacket(p_294972_, p_296217_, p_130535_);
+       }
+
+       public boolean isValidPacketType(Packet<?> p_294142_) {
+@@ -528,19 +546,28 @@
+       final Object2IntMap<Class<? extends Packet<? super T>>> classToId = Util.make(
+          new Object2IntOpenHashMap<>(), p_129613_ -> p_129613_.defaultReturnValue(-1)
+       );
++      /**
++       * @deprecated Use {@link #contextualIdToDeserializer} instead it allows for context to be passed to the deserializer
++       */
++      @Deprecated
+       private final List<Function<FriendlyByteBuf, ? extends Packet<? super T>>> idToDeserializer = Lists.newArrayList();
++      private final List<BiFunction<FriendlyByteBuf, ChannelHandlerContext, ? extends Packet<? super T>>> contextualIdToDeserializer = Lists.newArrayList();
+       private BundlerInfo bundlerInfo = BundlerInfo.EMPTY;
+       private final Set<Class<? extends Packet<T>>> extraClasses = new HashSet<>();
+-
++      
+       public <P extends Packet<? super T>> ConnectionProtocol.PacketSet<T> addPacket(Class<P> p_178331_, Function<FriendlyByteBuf, P> p_178332_) {
+-         int i = this.idToDeserializer.size();
+-         int j = this.classToId.put(p_178331_, i);
++         return addContextualPacket(p_178331_, (buf, channelHandlerContext) -> p_178332_.apply(buf));
++      }
++      
++      public <P extends Packet<? super T>> ConnectionProtocol.PacketSet<T> addContextualPacket(Class<P> packetClass, BiFunction<FriendlyByteBuf, ChannelHandlerContext, P> readerBuilder) {
++         int i = this.contextualIdToDeserializer.size();
++         int j = this.classToId.put(packetClass, i);
+          if (j != -1) {
+-            String s = "Packet " + p_178331_ + " is already registered to ID " + j;
++            String s = "Packet " + packetClass + " is already registered to ID " + j;
+             LOGGER.error(LogUtils.FATAL_MARKER, s);
+             throw new IllegalArgumentException(s);
+          } else {
+-            this.idToDeserializer.add(p_178332_);
++            this.contextualIdToDeserializer.add(readerBuilder);
+             return this;
+          }
+       }
+@@ -566,9 +593,9 @@
+       }
+
+       @Nullable
+-      public Packet<?> createPacket(int p_178328_, FriendlyByteBuf p_178329_) {
+-         Function<FriendlyByteBuf, ? extends Packet<? super T>> function = this.idToDeserializer.get(p_178328_);
+-         return function != null ? function.apply(p_178329_) : null;
++      public Packet<?> createPacket(int p_178328_, FriendlyByteBuf p_178329_, ChannelHandlerContext p_130535_) {
++         BiFunction<FriendlyByteBuf, ChannelHandlerContext, ? extends Packet<? super T>> function = this.contextualIdToDeserializer.get(p_178328_);
++         return function != null ? function.apply(p_178329_, p_130535_) : null;
+       }
+
+       public BundlerInfo bundlerInfo() {

patches/net/minecraft/network/PacketDecoder.java.patch

@@ -0,0 +1,11 @@
+--- a/net/minecraft/network/PacketDecoder.java
++++ b/net/minecraft/network/PacketDecoder.java
+@@ -28,7 +28,7 @@
+          ConnectionProtocol.CodecData<?> codecdata = attribute.get();
+          FriendlyByteBuf friendlybytebuf = new FriendlyByteBuf(p_130536_);
+          int j = friendlybytebuf.readVarInt();
+-         Packet<?> packet = codecdata.createPacket(j, friendlybytebuf);
++         Packet<?> packet = codecdata.createPacket(j, friendlybytebuf, p_130535_);
+          if (packet == null) {
+             throw new IOException("Bad packet id " + j);
+          } else {

patches/net/minecraft/network/protocol/common/ClientCommonPacketListener.java.patch

@@ -0,0 +1,11 @@
+--- a/net/minecraft/network/protocol/common/ClientCommonPacketListener.java
++++ b/net/minecraft/network/protocol/common/ClientCommonPacketListener.java
+@@ -2,7 +2,7 @@
+
+ import net.minecraft.network.ClientboundPacketListener;
+
+-public interface ClientCommonPacketListener extends ClientboundPacketListener {
++public interface ClientCommonPacketListener extends ClientboundPacketListener, net.neoforged.neoforge.common.extensions.IClientCommonPacketListenerExtension {
+    void handleKeepAlive(ClientboundKeepAlivePacket p_295236_);
+
+    void handlePing(ClientboundPingPacket p_296451_);

patches/net/minecraft/network/protocol/common/ServerCommonPacketListener.java.patch

@@ -0,0 +1,11 @@
+--- a/net/minecraft/network/protocol/common/ServerCommonPacketListener.java
++++ b/net/minecraft/network/protocol/common/ServerCommonPacketListener.java
+@@ -2,7 +2,7 @@
+
+ import net.minecraft.network.protocol.game.ServerPacketListener;
+
+-public interface ServerCommonPacketListener extends ServerPacketListener {
++public interface ServerCommonPacketListener extends ServerPacketListener, net.neoforged.neoforge.common.extensions.IClientboundPacketSenderExtension {
+    void handleKeepAlive(ServerboundKeepAlivePacket p_296457_);
+
+    void handlePong(ServerboundPongPacket p_294309_);

patches/net/minecraft/network/protocol/configuration/ServerConfigurationPacketListener.java.patch

@@ -0,0 +1,11 @@
+--- a/net/minecraft/network/protocol/configuration/ServerConfigurationPacketListener.java
++++ b/net/minecraft/network/protocol/configuration/ServerConfigurationPacketListener.java
+@@ -3,7 +3,7 @@
+ import net.minecraft.network.ConnectionProtocol;
+ import net.minecraft.network.protocol.common.ServerCommonPacketListener;
+
+-public interface ServerConfigurationPacketListener extends ServerCommonPacketListener {
++public interface ServerConfigurationPacketListener extends ServerCommonPacketListener, net.neoforged.neoforge.common.extensions.IServerConfigurationPacketListenerExtension {
+    @Override
+    default ConnectionProtocol protocol() {
+       return ConnectionProtocol.CONFIGURATION;

patches/net/minecraft/server/network/CommonListenerCookie.java.patch

@@ -0,0 +1,13 @@
+--- a/net/minecraft/server/network/CommonListenerCookie.java
++++ b/net/minecraft/server/network/CommonListenerCookie.java
+@@ -3,8 +3,8 @@
+ import com.mojang.authlib.GameProfile;
+ import net.minecraft.server.level.ClientInformation;
+
+-public record CommonListenerCookie(GameProfile gameProfile, int latency, ClientInformation clientInformation) {
++public record CommonListenerCookie(GameProfile gameProfile, int latency, ClientInformation clientInformation, boolean isModdedConnection) {
+    public static CommonListenerCookie createInitial(GameProfile p_302024_) {
+-      return new CommonListenerCookie(p_302024_, 0, ClientInformation.createDefault());
++      return new CommonListenerCookie(p_302024_, 0, ClientInformation.createDefault(), false);
+    }
+ }

patches/net/minecraft/server/network/ConfigurationTask.java.patch

@@ -0,0 +1,21 @@
+--- a/net/minecraft/server/network/ConfigurationTask.java
++++ b/net/minecraft/server/network/ConfigurationTask.java
+@@ -2,6 +2,7 @@
+
+ import java.util.function.Consumer;
+ import net.minecraft.network.protocol.Packet;
++import net.minecraft.resources.ResourceLocation;
+
+ public interface ConfigurationTask {
+    void start(Consumer<Packet<?>> p_294184_);
+@@ -9,6 +10,10 @@
+    ConfigurationTask.Type type();
+
+    public static record Type(String id) {
++      public Type(ResourceLocation location) {
++            this(location.toString());
++      }
++      
+       @Override
+       public String toString() {
+          return this.id;

patches/net/minecraft/server/network/ServerConfigurationPacketListenerImpl.java.patch

@@ -0,0 +1,133 @@
+--- a/net/minecraft/server/network/ServerConfigurationPacketListenerImpl.java
++++ b/net/minecraft/server/network/ServerConfigurationPacketListenerImpl.java
+@@ -12,11 +12,7 @@
+ import net.minecraft.network.TickablePacketListener;
+ import net.minecraft.network.chat.Component;
+ import net.minecraft.network.protocol.PacketUtils;
+-import net.minecraft.network.protocol.common.ClientboundCustomPayloadPacket;
+-import net.minecraft.network.protocol.common.ClientboundDisconnectPacket;
+-import net.minecraft.network.protocol.common.ClientboundUpdateTagsPacket;
+-import net.minecraft.network.protocol.common.ServerboundClientInformationPacket;
+-import net.minecraft.network.protocol.common.ServerboundResourcePackPacket;
++import net.minecraft.network.protocol.common.*;
+ import net.minecraft.network.protocol.common.custom.BrandPayload;
+ import net.minecraft.network.protocol.configuration.ClientboundRegistryDataPacket;
+ import net.minecraft.network.protocol.configuration.ClientboundUpdateEnabledFeaturesPacket;
+@@ -31,6 +27,8 @@
+ import net.minecraft.server.players.PlayerList;
+ import net.minecraft.tags.TagNetworkSerialization;
+ import net.minecraft.world.flag.FeatureFlags;
++import net.neoforged.neoforge.network.payload.ModdedNetworkQueryPayload;
++import net.neoforged.neoforge.network.registration.NetworkRegistry;
+ import org.slf4j.Logger;
+
+ public class ServerConfigurationPacketListenerImpl extends ServerCommonPacketListenerImpl implements TickablePacketListener, ServerConfigurationPacketListener {
+@@ -41,6 +39,8 @@
+    @Nullable
+    private ConfigurationTask currentTask;
+    private ClientInformation clientInformation;
++   private boolean isModdedConnection = false;
++   private boolean isHandlingModdedConfigurationPhase = false;
+
+    public ServerConfigurationPacketListenerImpl(MinecraftServer p_294645_, Connection p_295787_, CommonListenerCookie p_302003_) {
+       super(p_294645_, p_295787_, p_302003_);
+@@ -65,6 +65,11 @@
+    }
+
+    public void startConfiguration() {
++      this.send(new ModdedNetworkQueryPayload());
++      this.send(new ClientboundPingPacket(0));
++   }
++   
++   private void runConfiguration() {
+       this.send(new ClientboundCustomPayloadPacket(new BrandPayload(this.server.getServerModName())));
+       LayeredRegistryAccess<RegistryLayer> layeredregistryaccess = this.server.registries();
+       this.send(new ClientboundUpdateEnabledFeaturesPacket(FeatureFlags.REGISTRY.toNames(this.server.getWorldData().enabledFeatures())));
+@@ -86,6 +91,10 @@
+
+    private void addOptionalTasks() {
+       this.server.getServerResourcePack().ifPresent(p_296496_ -> this.configurationTasks.add(new ServerResourcePackConfigurationTask(p_296496_)));
++      
++      this.configurationTasks.add(new net.neoforged.neoforge.network.configuration.ModdedConfigurationPhaseStarted(this));
++      this.configurationTasks.addAll(net.neoforged.neoforge.common.NeoForge.EVENT_BUS.post(new net.neoforged.neoforge.network.event.OnGameConfiguration()).getConfigurationTasks());
++      this.configurationTasks.add(new net.neoforged.neoforge.network.configuration.ModdedConfigurationPhaseCompleted(this));
+    }
+
+    @Override
+@@ -100,7 +109,40 @@
+          this.finishCurrentTask(ServerResourcePackConfigurationTask.TYPE);
+       }
+    }
+-
++   
++   @Override
++   public void handleCustomPayload(ServerboundCustomPayloadPacket p_294276_) {
++      if (p_294276_.payload() instanceof ModdedNetworkQueryPayload moddedEnvironmentPayload) {
++         this.isModdedConnection = true;
++         NetworkRegistry.getInstance()
++            .onModdedConnectionDetectedAtServer(
++                    this,
++                    moddedEnvironmentPayload.configuration(),
++                    moddedEnvironmentPayload.play()
++            );
++         return;
++      }
++      
++      if (!isHandlingModdedConfigurationPhase) {
++          super.handleCustomPayload(p_294276_);
++          return;
++      }
++      
++      NetworkRegistry.getInstance().onModdedPacketAtServer(this, p_294276_);
++   }
++   
++   @Override
++   public void handlePong(ServerboundPongPacket p_295142_) {
++      super.handlePong(p_295142_);
++      if (p_295142_.getId() == 0) {
++         if (!this.isModdedConnection && !net.neoforged.neoforge.network.registration.NetworkRegistry.getInstance().onVanillaConnectionDetectedAtServer(this)) {
++            return;
++         }
++         
++         this.runConfiguration();
++      }
++   }
++   
+    @Override
+    public void handleConfigurationFinished(ServerboundFinishConfigurationPacket p_294283_) {
+       this.connection.suspendInboundAfterProtocolChange();
+@@ -121,7 +163,7 @@
+          }
+
+          ServerPlayer serverplayer = playerlist.getPlayerForLogin(this.gameProfile, this.clientInformation);
+-         playerlist.placeNewPlayer(this.connection, serverplayer, this.createCookie(this.clientInformation));
++         playerlist.placeNewPlayer(this.connection, serverplayer, this.createCookie(this.clientInformation, this.isModdedConnection));
+          this.connection.resumeInboundAfterProtocolChange();
+       } catch (Exception exception) {
+          LOGGER.error("Couldn't place player in world", (Throwable)exception);
+@@ -147,7 +189,8 @@
+       }
+    }
+
+-   private void finishCurrentTask(ConfigurationTask.Type p_294853_) {
++   @Override
++   public void finishCurrentTask(ConfigurationTask.Type p_294853_) {
+       ConfigurationTask.Type configurationtask$type = this.currentTask != null ? this.currentTask.type() : null;
+       if (!p_294853_.equals(configurationtask$type)) {
+          throw new IllegalStateException("Unexpected request for task finish, current task: " + configurationtask$type + ", requested: " + p_294853_);
+@@ -155,5 +198,15 @@
+          this.currentTask = null;
+          this.startNextTask();
+       }
++   }
++   
++   public void onModdedConfigurationPhaseStarted() {
++      isHandlingModdedConfigurationPhase = true;
++      finishCurrentTask(net.neoforged.neoforge.network.configuration.ModdedConfigurationPhaseStarted.TYPE);
++   }
++   
++   public void onModdedConfigurationPhaseEnded() {
++      isHandlingModdedConfigurationPhase = false;
++      finishCurrentTask(net.neoforged.neoforge.network.configuration.ModdedConfigurationPhaseCompleted.TYPE);
+    }
+ }