fix(velocity): linked player textures

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;
+    }
+}

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

@@ -48,16 +48,21 @@
 import io.netty.channel.Channel;
 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;
@@ -110,6 +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;
@@ -154,9 +162,22 @@ public void onGameProfileRequest(GameProfileRequestEvent event) {
             GameProfile profile = new GameProfile(
                     player.getCorrectUniqueId(),
                     player.getCorrectUsername(),
-                    List.of(DEFAULT_TEXTURE_PROPERTY) // Otherwise game server will try to fetch the skin from Mojang
+                    player.isLinked() ? Collections.emptyList() : List.of(DEFAULT_TEXTURE_PROPERTY) // Otherwise game server will try to fetch the skin from Mojang
             );
 
+            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);
         }
     }