fix: use og server host for transfer

server-deploy/overrides/sfcraft/announcements/2.3_update.txt

@@ -1,8 +1,8 @@
-§d§lSFCraft 已更新到 2.2.1。
+§d§lSFCraft 已更新到 2.3。
 §a主要改动：
  - 修复了非被斩首怪物掉落头颅的问题
  - 修复了 4K 图片无法下载到服务器中的问题。现在高分辨率图片会被降采样
  - 修复了鞘翅撞进地狱门需要有空隙的问题
 
 具体信息请查阅我们的更新日志：
-§bhttps://sfclub.cc/~sfcraft/changelog/2026-08-08/
+§bhttps://sfclub.cc/~sfcraft/changelog/2026-08-24/

src/main/java/io/ib67/sfcraft/mixin/common/ConnectionMixin.java

@@ -0,0 +1,26 @@
+package io.ib67.sfcraft.mixin.common;
+
+import io.ib67.sfcraft.network.HandshakeAddress;
+import net.minecraft.network.Connection;
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+
+/**
+ * Connection 从握手一路存活到 play 阶段,拿来记玩家自报的进服地址。
+ */
+@Mixin(Connection.class)
+public class ConnectionMixin implements HandshakeAddress.Holder {
+    @Unique
+    private HandshakeAddress sfcraft$handshakeAddress;
+
+    @Override
+    public @Nullable HandshakeAddress sfcraft$handshakeAddress() {
+        return sfcraft$handshakeAddress;
+    }
+
+    @Override
+    public void sfcraft$setHandshakeAddress(@Nullable HandshakeAddress address) {
+        this.sfcraft$handshakeAddress = address;
+    }
+}

src/main/java/io/ib67/sfcraft/mixin/common/bridge/ServerCommonNetworkHandlerBridge.java

@@ -0,0 +1,12 @@
+package io.ib67.sfcraft.mixin.common.bridge;
+
+import net.minecraft.network.Connection;
+import net.minecraft.server.network.ServerCommonPacketListenerImpl;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+@Mixin(ServerCommonPacketListenerImpl.class)
+public interface ServerCommonNetworkHandlerBridge {
+    @Accessor("connection")
+    Connection sfcraft$getConnection();
+}

src/main/java/io/ib67/sfcraft/mixin/server/ServerHandshakeNetworkHandlerMixin.java

@@ -2,7 +2,9 @@ package io.ib67.sfcraft.mixin.server;
 
 import io.ib67.sfcraft.SFCraft;
 import io.ib67.sfcraft.callback.SFCallbacks;
+import io.ib67.sfcraft.network.HandshakeAddress;
 import net.minecraft.network.Connection;
+import net.minecraft.network.protocol.handshake.ClientIntentionPacket;
 import net.minecraft.network.protocol.status.ServerStatus;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.network.ServerHandshakePacketListenerImpl;
@@ -11,7 +13,9 @@ import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
 @Mixin(ServerHandshakePacketListenerImpl.class)
 public abstract class ServerHandshakeNetworkHandlerMixin {
@@ -19,6 +23,15 @@ public abstract class ServerHandshakeNetworkHandlerMixin {
     @Final
     private Connection connection;
 
+    /**
+     * 记下玩家实际用来进服的地址,房间 transfer 时把他送回同一个入口。
+     */
+    @Inject(method = "handleIntention", at = @At("HEAD"))
+    private void sf$captureAddress(ClientIntentionPacket packet, CallbackInfo ci) {
+        ((HandshakeAddress.Holder) connection)
+                .sfcraft$setHandshakeAddress(HandshakeAddress.sanitize(packet.hostName(), packet.port()));
+    }
+
     @Redirect(method = "handleIntention", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/MinecraftServer;getStatus()Lnet/minecraft/network/protocol/status/ServerStatus;"))
     public ServerStatus getMetadata(MinecraftServer instance) {
         var result = SFCallbacks.MOTD.invoker().onMotd(instance,connection);

src/main/java/io/ib67/sfcraft/module/RoomModule.java

@@ -10,6 +10,7 @@ import io.ib67.kiwi.tuple.Tuple2;
 import io.ib67.sfcraft.ServerModule;
 import io.ib67.sfcraft.config.SFConfig;
 import io.ib67.sfcraft.inject.MinecraftServerSupplier;
+import io.ib67.sfcraft.network.HandshakeAddress;
 import io.ib67.sfcraft.registry.RoomRegistry;
 import lombok.extern.log4j.Log4j2;
 import net.fabricmc.fabric.api.command.v2.CommandRegistrationCallback;
@@ -20,7 +21,6 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.network.PacketSendListener;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.common.ClientboundStoreCookiePacket;
-import net.minecraft.network.protocol.common.ClientboundTransferPacket;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.Identifier;
 import net.minecraft.server.level.TicketType;
@@ -83,8 +83,9 @@ public class RoomModule extends ServerModule {
             return 0;
         }
         var networkHandler = player.connection;
+        var transfer = HandshakeAddress.transferPacketFor(player, config);
         networkHandler.send(new ClientboundStoreCookiePacket(ROOM_COOKIE, EMPTY), PacketSendListener.thenRun(() -> {
-            networkHandler.send(new ClientboundTransferPacket(config.domain, config.port));
+            networkHandler.send(transfer);
         }));
         return 1;
     }

src/main/java/io/ib67/sfcraft/network/HandshakeAddress.java

@@ -0,0 +1,61 @@
+package io.ib67.sfcraft.network;
+
+import io.ib67.sfcraft.config.SFConfig;
+import io.ib67.sfcraft.mixin.common.bridge.ServerCommonNetworkHandlerBridge;
+import net.minecraft.network.protocol.common.ClientboundTransferPacket;
+import net.minecraft.server.level.ServerPlayer;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * 玩家在握手包里自报的服务器地址,也就是他实际用来进服的那个地址。
+ * 由 {@code ServerHandshakeNetworkHandlerMixin} 记到 {@link net.minecraft.network.Connection} 上,
+ * transfer 时原样回显,让玩家重连回原本的入口而不是配置里写死的那个。
+ */
+public record HandshakeAddress(String host, int port) {
+    /**
+     * 代理(BungeeCord/Velocity legacy forwarding、FML)会把转发数据拼在 hostName 后面,以 '\0' 分隔。
+     */
+    private static final char FORWARDING_SEPARATOR = '\0';
+
+    /**
+     * 挂在 {@link net.minecraft.network.Connection} 上的握手地址,由 ConnectionMixin 实现。
+     */
+    public interface Holder {
+        @Nullable
+        HandshakeAddress sfcraft$handshakeAddress();
+
+        void sfcraft$setHandshakeAddress(@Nullable HandshakeAddress address);
+    }
+
+    /**
+     * 清洗握手包里的 hostName / port,不可用时返回 null。
+     */
+    public static @Nullable HandshakeAddress sanitize(String hostName, int port) {
+        if (hostName == null || port <= 0 || port > 65535) return null;
+        var host = hostName;
+        var separator = host.indexOf(FORWARDING_SEPARATOR);
+        if (separator >= 0) host = host.substring(0, separator);
+        // SRV 解析出来的 FQDN 可能带尾点
+        while (host.endsWith(".")) host = host.substring(0, host.length() - 1);
+        host = host.trim();
+        return host.isEmpty() ? null : new HandshakeAddress(host, port);
+    }
+
+    /**
+     * 读玩家当前连接上记的握手地址,拿不到返回 null。
+     */
+    public static @Nullable HandshakeAddress of(ServerPlayer player) {
+        var connection = ((ServerCommonNetworkHandlerBridge) player.connection).sfcraft$getConnection();
+        return connection instanceof Holder holder ? holder.sfcraft$handshakeAddress() : null;
+    }
+
+    /**
+     * 优先把玩家送回他自己用的地址,拿不到才回退配置里的 domain / port。
+     */
+    public static ClientboundTransferPacket transferPacketFor(ServerPlayer player, SFConfig fallback) {
+        var address = of(player);
+        return address == null
+                ? new ClientboundTransferPacket(fallback.domain, fallback.port)
+                : new ClientboundTransferPacket(address.host(), address.port());
+    }
+}

src/main/java/io/ib67/sfcraft/room/RoomTeleporter.java

@@ -6,13 +6,13 @@ import io.ib67.sfcraft.config.SFConfig;
 import io.ib67.sfcraft.inject.MinecraftServerSupplier;
 import io.ib67.sfcraft.module.RoomModule;
 import io.ib67.sfcraft.module.SignatureService;
+import io.ib67.sfcraft.network.HandshakeAddress;
 import io.ib67.sfcraft.registry.RoomRegistry;
 import io.ib67.sfcraft.subserver.Room;
 import io.netty.buffer.Unpooled;
 import net.minecraft.network.PacketSendListener;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.common.ClientboundStoreCookiePacket;
-import net.minecraft.network.protocol.common.ClientboundTransferPacket;
 import net.minecraft.resources.Identifier;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.util.CommonColors;
@@ -44,6 +44,8 @@ public class RoomTeleporter {
             throw new IllegalStateException("world isn't exist");
         }
         var networkHandler = player.connection;
+        // 趁连接还在 play 阶段先取好目标地址
+        var transfer = HandshakeAddress.transferPacketFor(player, config);
         networkHandler.switchToConfig();
         var request = new RequestedRoom(room.getServerIdentifier(), name, finalUuid);
         var requestBuf = Unpooled.buffer();
@@ -58,7 +60,7 @@ public class RoomTeleporter {
                 )
         );
         networkHandler.send(new ClientboundStoreCookiePacket(ROOM_COOKIE, cookie), PacketSendListener.thenRun(() -> {
-            networkHandler.send(new ClientboundTransferPacket(config.domain, config.port));
+            networkHandler.send(transfer);
         }));
     }
 }

src/main/resources/sfcraft.mixins.json

@@ -9,11 +9,13 @@
   "client": [
   ],
   "server": [
+    "common.ConnectionMixin",
     "common.EntityMixin",
     "common.MobEntityMixin",
     "common.PlayerEntityMixin",
     "common.bridge.EntityBridge",
     "common.bridge.ServerChunkManagerBridge",
+    "common.bridge.ServerCommonNetworkHandlerBridge",
     "common.bridge.ServerPlayerBridge",
     "common.bridge.ServerWorldBridge",
     "common.fixes.EndermanEntityMixin",