Reduce session server lookups

bungee/src/main/java/org/geysermc/floodgate/listener/BungeeListener.java

@@ -33,6 +33,8 @@
 import io.netty.util.AttributeKey;
 import java.lang.reflect.Field;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 import net.md_5.bungee.api.connection.PendingConnection;
 import net.md_5.bungee.api.event.LoginEvent;
 import net.md_5.bungee.api.event.PlayerDisconnectEvent;
@@ -49,7 +51,10 @@
 import org.geysermc.floodgate.config.ProxyFloodgateConfig;
 import org.geysermc.floodgate.skin.SkinApplier;
 import org.geysermc.floodgate.skin.SkinDataImpl;
+import org.geysermc.floodgate.util.Constants;
+import org.geysermc.floodgate.util.HttpClient;
 import org.geysermc.floodgate.util.LanguageManager;
+import org.geysermc.floodgate.util.MojangUtils;
 import org.geysermc.floodgate.util.ReflectionUtils;
 
 @SuppressWarnings("ConstantConditions")
@@ -80,6 +85,8 @@ public final class BungeeListener implements Listener {
     @Named("kickMessageAttribute")
     private AttributeKey<String> kickMessageAttribute;
 
+    @Inject private HttpClient httpClient;
+
     @EventHandler(priority = EventPriority.LOWEST)
     public void onPreLogin(PreLoginEvent event) {
         // well, no reason to check if the player will be kicked anyway
@@ -130,9 +137,35 @@ public void onPostLogin(PostLoginEvent event) {
         // To fix the February 2 2022 Mojang authentication changes
         if (!config.isSendFloodgateData()) {
             FloodgatePlayer player = api.getPlayer(event.getPlayer().getUniqueId());
-            if (player != null && !player.isLinked()) {
-                skinApplier.applySkin(player, new SkinDataImpl("", ""));
+
+            if (player == null) {
+                return;
+            }
+
+            if (!player.isLinked()) {
+                skinApplier.applySkin(player, new SkinDataImpl(
+                        Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+                        Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE
+                ));
+
+                return;
             }
+
+            CompletableFuture.supplyAsync(() -> {
+                        try {
+                            return MojangUtils.getSkinCached(httpClient, player.getJavaUniqueId());
+                        } catch (ExecutionException e) {
+                            throw new RuntimeException(e);
+                        }
+                    }).thenAccept(skin -> skinApplier.applySkin(player, skin))
+                    .exceptionally(e -> {
+                        logger.error("Failed to get skin for player " + player.getJavaUniqueId() + ", applying default.", e);
+                        skinApplier.applySkin(player, new SkinDataImpl(
+                                Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+                                Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE
+                        ));
+                        return null;
+                    });
         }
     }
 

core/src/main/java/org/geysermc/floodgate/skin/SkinDataImpl.java

@@ -29,6 +29,7 @@
 import java.util.Objects;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.geysermc.floodgate.api.event.skin.SkinApplyEvent.SkinData;
+import org.geysermc.floodgate.util.Constants;
 
 public class SkinDataImpl implements SkinData {
     private final String value;
@@ -55,4 +56,9 @@ public static SkinData from(JsonObject data) {
     public @NonNull String signature() {
         return signature;
     }
+
+    public static final SkinData DEFAULT_SKIN = new SkinDataImpl(
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_SIGNATURE
+    );
 }

core/src/main/java/org/geysermc/floodgate/util/MojangUtils.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2019-2024 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Floodgate
+ */
+
+package org.geysermc.floodgate.util;
+
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import lombok.NonNull;
+import org.geysermc.floodgate.api.event.skin.SkinApplyEvent.SkinData;
+import org.geysermc.floodgate.skin.SkinDataImpl;
+import org.geysermc.floodgate.util.HttpClient.HttpResponse;
+
+public class MojangUtils {
+
+    private static final String SESSION_SERVER =
+            "https://sessionserver.mojang.com/session/minecraft/profile/%s?unsigned=false";
+
+    private static final Cache<UUID, SkinData> SKIN_CACHE = CacheBuilder.newBuilder()
+            .expireAfterWrite(5, TimeUnit.MINUTES)
+            .maximumSize(500)
+            .build();
+
+    public static @NonNull SkinData getSkinCached(
+            HttpClient httpClient,
+            UUID playerId
+    ) throws ExecutionException {
+        return SKIN_CACHE.get(playerId, () -> getSkin(httpClient, playerId));
+    }
+
+    public static @NonNull SkinData getSkin(HttpClient httpClient, UUID playerId) {
+        final HttpResponse<JsonObject> httpResponse = httpClient.get(String.format(SESSION_SERVER, playerId.toString()));
+
+        if (httpResponse.getHttpCode() != 200) {
+            return SkinDataImpl.DEFAULT_SKIN;
+        }
+
+        JsonObject response = httpResponse.getResponse();
+
+        if (response == null) {
+            return SkinDataImpl.DEFAULT_SKIN;
+        }
+
+        JsonArray properties = response.getAsJsonArray("properties");
+
+        if (properties.size() == 0) {
+            return SkinDataImpl.DEFAULT_SKIN;
+        }
+
+        for (JsonElement property : properties) {
+            if (!property.isJsonObject()) {
+                continue;
+            }
+
+            JsonObject propertyObject = property.getAsJsonObject();
+
+            if (!propertyObject.has("name")
+                    || !propertyObject.has("value")
+                    || !propertyObject.has("signature")
+                    || !propertyObject.get("name").getAsString().equals("textures")) {
+                continue;
+            }
+
+            return new SkinDataImpl(
+                    propertyObject.get("value").getAsString(),
+                    propertyObject.get("signature").getAsString()
+            );
+        }
+
+        return SkinDataImpl.DEFAULT_SKIN;
+    }
+}

core/src/main/templates/org/geysermc/floodgate/util/Constants.java

@@ -70,4 +70,7 @@ public final class Constants {
     public static final int HANDSHAKE_PACKET_ID = 0;
     public static final int LOGIN_SUCCESS_PACKET_ID = 2;
     public static final int SET_COMPRESSION_PACKET_ID = 3;
+
+    public static final String DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE = "ewogICJ0aW1lc3RhbXAiIDogMTcxNTMwNTM4NDQwOSwKICAicHJvZmlsZUlkIiA6ICJjZDZkODYwMzRhMWI0YTgxYjhhN2E2Y2IyM2Y5MjI4MCIsCiAgInByb2ZpbGVOYW1lIiA6ICJKdWVsbGU5MTc5IiwKICAic2lnbmF0dXJlUmVxdWlyZWQiIDogdHJ1ZSwKICAidGV4dHVyZXMiIDogewogICAgIlNLSU4iIDogewogICAgICAidXJsIiA6ICJodHRwOi8vdGV4dHVyZXMubWluZWNyYWZ0Lm5ldC90ZXh0dXJlLzMxZjQ3N2ViMWE3YmVlZTYzMWMyY2E2NGQwNmY4ZjY4ZmE5M2EzMzg2ZDA0NDUyYWIyN2Y0M2FjZGYxYjYwY2IiCiAgICB9CiAgfQp9";
+    public static final String DEFAULT_MINECRAFT_JAVA_SKIN_SIGNATURE = "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";
 }

spigot/src/main/java/org/geysermc/floodgate/addon/data/SpigotDataHandler.java

@@ -29,6 +29,7 @@
 import static org.geysermc.floodgate.util.ReflectionUtils.setValue;
 
 import com.mojang.authlib.GameProfile;
+import com.mojang.authlib.properties.Property;
 import io.netty.channel.Channel;
 import io.netty.util.AttributeKey;
 import java.lang.reflect.InvocationTargetException;
@@ -38,9 +39,17 @@
 import org.geysermc.floodgate.player.FloodgateHandshakeHandler;
 import org.geysermc.floodgate.player.FloodgateHandshakeHandler.HandshakeResult;
 import org.geysermc.floodgate.util.ClassNames;
+import org.geysermc.floodgate.util.Constants;
 import org.geysermc.floodgate.util.ProxyUtils;
 
 public final class SpigotDataHandler extends CommonDataHandler {
+
+    private static final Property DEFAULT_TEXTURE_PROPERTY = new Property(
+            "textures",
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_SIGNATURE
+    );
+
     private Object networkManager;
     private FloodgatePlayer player;
     private boolean proxyData;
@@ -171,6 +180,14 @@ private boolean checkAndHandleLogin(Object packet) throws Exception {
                     player.getCorrectUniqueId(), player.getCorrectUsername()
             );
 
+            if (!player.isLinked()) {
+                // Otherwise game server will try to fetch the skin from Mojang
+                gameProfile.getProperties().put(
+                        "textures",
+                        DEFAULT_TEXTURE_PROPERTY
+                );
+            }
+
             // we have to fake the offline player (login) cycle
 
             if (ClassNames.IS_PRE_1_20_2) {

spigot/src/main/java/org/geysermc/floodgate/listener/PaperProfileListener.java

@@ -38,6 +38,7 @@
 import org.bukkit.event.player.PlayerJoinEvent;
 import org.geysermc.floodgate.api.SimpleFloodgateApi;
 import org.geysermc.floodgate.api.player.FloodgatePlayer;
+import org.geysermc.floodgate.util.Constants;
 
 public final class PaperProfileListener implements Listener {
     @Inject private SimpleFloodgateApi api;
@@ -62,7 +63,14 @@ public void onFill(PreFillProfileEvent event) {
         }
 
         Set<ProfileProperty> properties = new HashSet<>(event.getPlayerProfile().getProperties());
-        properties.add(new ProfileProperty("textures", "", ""));
+        properties.add(
+                new ProfileProperty(
+                        "textures",
+                        Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+                        Constants.DEFAULT_MINECRAFT_JAVA_SKIN_SIGNATURE
+                )
+        );
+
         event.setProperties(properties);
     }
 

velocity/src/main/java/org/geysermc/floodgate/listener/VelocityListener.java

@@ -49,19 +49,26 @@
 import io.netty.util.AttributeKey;
 import java.lang.reflect.Field;
 import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import net.kyori.adventure.text.Component;
 import org.geysermc.floodgate.api.ProxyFloodgateApi;
+import org.geysermc.floodgate.api.event.skin.SkinApplyEvent.SkinData;
 import org.geysermc.floodgate.api.logger.FloodgateLogger;
 import org.geysermc.floodgate.api.player.FloodgatePlayer;
 import org.geysermc.floodgate.config.ProxyFloodgateConfig;
+import org.geysermc.floodgate.util.Constants;
+import org.geysermc.floodgate.util.HttpClient;
 import org.geysermc.floodgate.util.LanguageManager;
+import org.geysermc.floodgate.util.MojangUtils;
 
 public final class VelocityListener {
     private static final Field INITIAL_MINECRAFT_CONNECTION;
     private static final Field INITIAL_CONNECTION_DELEGATE;
     private static final Field CHANNEL;
+    private static final Property DEFAULT_TEXTURE_PROPERTY;
 
     static {
         Class<?> initialConnection = getPrefixedClass("connection.client.InitialInboundConnection");
@@ -82,6 +89,11 @@ public final class VelocityListener {
         }
 
         CHANNEL = getFieldOfType(minecraftConnection, Channel.class);
+        DEFAULT_TEXTURE_PROPERTY = new Property(
+                "textures",
+                Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+                Constants.DEFAULT_MINECRAFT_JAVA_SKIN_SIGNATURE
+        );
     }
 
     private final Cache<InboundConnection, FloodgatePlayer> playerCache =
@@ -103,6 +115,9 @@ public final class VelocityListener {
     @Named("kickMessageAttribute")
     private AttributeKey<String> kickMessageAttribute;
 
+    @Inject
+    private HttpClient httpClient;
+
     @Subscribe(order = PostOrder.EARLY)
     public void onPreLogin(PreLoginEvent event) {
         FloodgatePlayer player = null;
@@ -147,12 +162,22 @@ public void onGameProfileRequest(GameProfileRequestEvent event) {
             GameProfile profile = new GameProfile(
                     player.getCorrectUniqueId(),
                     player.getCorrectUsername(),
-                    Collections.emptyList()
+                    player.isLinked() ? Collections.emptyList() : List.of(DEFAULT_TEXTURE_PROPERTY) // Otherwise game server will try to fetch the skin from Mojang
             );
-            // The texture properties addition is to fix the February 2 2022 Mojang authentication changes
-            if (!config.isSendFloodgateData() && !player.isLinked()) {
-                profile = profile.addProperty(new Property("textures", "", ""));
+
+            if (player.isLinked()) {
+                // Do texture lookup to session server
+                try {
+                    SkinData skin = MojangUtils.getSkinCached(httpClient,
+                            player.getJavaUniqueId());
+
+                    profile.addProperty(new Property("textures", skin.value(), skin.signature()));
+                } catch (ExecutionException e) {
+                    logger.error("Failed to get skin for player " + player.getJavaUniqueId() + ", applying default.", e);
+                    profile.addProperty(DEFAULT_TEXTURE_PROPERTY);
+                }
             }
+
             event.setGameProfile(profile);
         }
     }