Reduce session server lookups (#509)

* fix: add default skin to gameprofiles

* fix: add signatures by default to prevent issues

* cleanup

* no longer apply empty textures

* revert formatting change

* fix(spigot): linked player textures

* fix(velocity): linked player textures

* fix(bungeecord): apply linked textures

* Made the MojangUtils class instance based, removed some unneeded code

* Don't block Velocity event threads, made the Bungee variant work

* Add some comments

---------

Co-authored-by: bridge <haha@haha.com>
Co-authored-by: Tim203 <mctim203@gmail.com>

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

@@ -39,6 +39,7 @@ import net.md_5.bungee.api.event.PlayerDisconnectEvent;
 import net.md_5.bungee.api.event.PostLoginEvent;
 import net.md_5.bungee.api.event.PreLoginEvent;
 import net.md_5.bungee.api.plugin.Listener;
+import net.md_5.bungee.api.plugin.Plugin;
 import net.md_5.bungee.connection.InitialHandler;
 import net.md_5.bungee.event.EventHandler;
 import net.md_5.bungee.event.EventPriority;
@@ -46,10 +47,10 @@ import net.md_5.bungee.netty.ChannelWrapper;
 import org.geysermc.floodgate.api.ProxyFloodgateApi;
 import org.geysermc.floodgate.api.logger.FloodgateLogger;
 import org.geysermc.floodgate.api.player.FloodgatePlayer;
-import org.geysermc.floodgate.config.ProxyFloodgateConfig;
 import org.geysermc.floodgate.skin.SkinApplier;
 import org.geysermc.floodgate.skin.SkinDataImpl;
 import org.geysermc.floodgate.util.LanguageManager;
+import org.geysermc.floodgate.util.MojangUtils;
 import org.geysermc.floodgate.util.ReflectionUtils;
 
 @SuppressWarnings("ConstantConditions")
@@ -66,7 +67,7 @@ public final class BungeeListener implements Listener {
         checkNotNull(PLAYER_NAME, "Initial name field cannot be null");
     }
 
-    @Inject private ProxyFloodgateConfig config;
+    @Inject private Plugin plugin;
     @Inject private ProxyFloodgateApi api;
     @Inject private LanguageManager languageManager;
     @Inject private FloodgateLogger logger;
@@ -80,6 +81,8 @@ public final class BungeeListener implements Listener {
     @Named("kickMessageAttribute")
     private AttributeKey<String> kickMessageAttribute;
 
+    @Inject private MojangUtils mojangUtils;
+
     @EventHandler(priority = EventPriority.LOWEST)
     public void onPreLogin(PreLoginEvent event) {
         // well, no reason to check if the player will be kicked anyway
@@ -127,13 +130,28 @@ public final class BungeeListener implements Listener {
 
     @EventHandler(priority = EventPriority.LOWEST)
     public void onPostLogin(PostLoginEvent event) {
-        // To fix the February 2 2022 Mojang authentication changes
+        FloodgatePlayer player = api.getPlayer(event.getPlayer().getUniqueId());
-        if (!config.isSendFloodgateData()) {
+
-            FloodgatePlayer player = api.getPlayer(event.getPlayer().getUniqueId());
+        // Skin look up (on Spigot and friends) would result in it failing, so apply a default skin
-            if (player != null && !player.isLinked()) {
+        if (!player.isLinked()) {
-                skinApplier.applySkin(player, new SkinDataImpl("", ""));
+            skinApplier.applySkin(player, SkinDataImpl.DEFAULT_SKIN);
-            }
+            return;
         }
+
+        // Floodgate players are seen as offline mode players, meaning we have to look up
+        // the linked player's textures ourselves
+
+        event.registerIntent(plugin);
+
+        mojangUtils.skinFor(player.getJavaUniqueId())
+                .exceptionally(exception -> {
+                    logger.debug("Unexpected skin fetch error for " + player.getJavaUniqueId(), exception);
+                    return SkinDataImpl.DEFAULT_SKIN;
+                })
+                .thenAccept(skin -> {
+                    skinApplier.applySkin(player, skin);
+                    event.completeIntent(plugin);
+                });
     }
 
     @EventHandler(priority = EventPriority.HIGHEST)

bungee/src/main/java/org/geysermc/floodgate/pluginmessage/BungeeSkinApplier.java

@@ -92,8 +92,6 @@ public final class BungeeSkinApplier implements SkinApplier {
         SkinData currentSkin = currentSkin(properties);
 
         SkinApplyEvent event = new SkinApplyEventImpl(floodgatePlayer, currentSkin, skinData);
-        event.setCancelled(floodgatePlayer.isLinked());
-
         eventBus.fire(event);
 
         if (event.isCancelled()) {

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

@@ -29,8 +29,14 @@ import com.google.gson.JsonObject;
 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 {
+    public static final SkinData DEFAULT_SKIN = new SkinDataImpl(
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_SIGNATURE
+    );
+
     private final String value;
     private final String signature;
 

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

@@ -0,0 +1,110 @@
+/*
+ * 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 com.google.inject.Inject;
+import com.google.inject.Singleton;
+import com.google.inject.name.Named;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+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;
+
+@Singleton
+public class MojangUtils {
+    private final Cache<UUID, SkinData> SKIN_CACHE = CacheBuilder.newBuilder()
+            .expireAfterWrite(5, TimeUnit.MINUTES)
+            .maximumSize(500)
+            .build();
+
+    @Inject private HttpClient httpClient;
+    @Inject
+    @Named("commonPool")
+    private ExecutorService commonPool;
+
+    public CompletableFuture<@NonNull SkinData> skinFor(UUID playerId) {
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                return SKIN_CACHE.get(playerId, () -> fetchSkinFor(playerId));
+            } catch (ExecutionException exception) {
+                throw new RuntimeException(exception.getCause());
+            }
+        }, commonPool);
+    }
+
+    private @NonNull SkinData fetchSkinFor(UUID playerId) {
+        HttpResponse<JsonObject> httpResponse = httpClient.get(
+                String.format(Constants.PROFILE_WITH_PROPERTIES_URL, 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

@@ -56,6 +56,9 @@ public final class Constants {
     public static final String LATEST_VERSION_URL =
             "https://download.geysermc.org/v2/projects/%s/versions/latest/builds/latest";
 
+    public static final String PROFILE_WITH_PROPERTIES_URL =
+            "https://sessionserver.mojang.com/session/minecraft/profile/%s?unsigned=false";
+
 
     public static final String NTP_SERVER = "time.cloudflare.com";
     public static final String INTERNAL_ERROR_MESSAGE =
@@ -70,4 +73,7 @@ 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 = "ewogICJ0aW1lc3RhbXAiIDogMTcxNTcxNzM1NTI2MywKICAicHJvZmlsZUlkIiA6ICIyMWUzNjdkNzI1Y2Y0ZTNiYjI2OTJjNGEzMDBhNGRlYiIsCiAgInByb2ZpbGVOYW1lIiA6ICJHZXlzZXJNQyIsCiAgInNpZ25hdHVyZVJlcXVpcmVkIiA6IHRydWUsCiAgInRleHR1cmVzIiA6IHsKICAgICJTS0lOIiA6IHsKICAgICAgInVybCIgOiAiaHR0cDovL3RleHR1cmVzLm1pbmVjcmFmdC5uZXQvdGV4dHVyZS8zMWY0NzdlYjFhN2JlZWU2MzFjMmNhNjRkMDZmOGY2OGZhOTNhMzM4NmQwNDQ1MmFiMjdmNDNhY2RmMWI2MGNiIgogICAgfQogIH0KfQ";
+    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.getCastedValue;
 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 +39,16 @@ import org.geysermc.floodgate.config.FloodgateConfig;
 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 +179,13 @@ public final class SpigotDataHandler extends CommonDataHandler {
                     player.getCorrectUniqueId(), player.getCorrectUsername()
             );
 
+            if (!player.isLinked()) {
+                // Otherwise game server will try to fetch the skin from Mojang.
+                // No need to worry that this overrides proxy data, because those won't reach this
+                // method / are already removed (in the case of username validation)
+                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

@@ -26,20 +26,24 @@
 package org.geysermc.floodgate.listener;
 
 import com.destroystokyo.paper.event.profile.PreFillProfileEvent;
-import com.destroystokyo.paper.profile.PlayerProfile;
 import com.destroystokyo.paper.profile.ProfileProperty;
 import com.google.inject.Inject;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
-import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
-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 {
+    private static final ProfileProperty DEFAULT_TEXTURE_PROPERTY = new ProfileProperty(
+            "textures",
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_TEXTURE,
+            Constants.DEFAULT_MINECRAFT_JAVA_SKIN_SIGNATURE
+    );
+
     @Inject private SimpleFloodgateApi api;
 
     @EventHandler
@@ -62,26 +66,8 @@ public final class PaperProfileListener implements Listener {
         }
 
         Set<ProfileProperty> properties = new HashSet<>(event.getPlayerProfile().getProperties());
-        properties.add(new ProfileProperty("textures", "", ""));
+        properties.add(DEFAULT_TEXTURE_PROPERTY);
+
         event.setProperties(properties);
     }
-
-    @EventHandler
-    public void onPlayerJoin(PlayerJoinEvent event) {
-        Player bukkitPlayer = event.getPlayer();
-        FloodgatePlayer player = api.getPlayer(bukkitPlayer.getUniqueId());
-        if (player == null || player.isLinked()) {
-            return;
-        }
-
-        PlayerProfile profile = bukkitPlayer.getPlayerProfile();
-        if (profile.getProperties().stream().noneMatch(
-                prop -> "textures".equals(prop.getName()) && prop.getValue().isEmpty()
-                        && prop.getSignature() != null && prop.getSignature().isEmpty())) {
-            return;
-        }
-
-        profile.removeProperty("textures");
-        bukkitPlayer.setPlayerProfile(profile);
-    }
 }

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

@@ -36,6 +36,7 @@ import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
 import com.google.inject.Inject;
 import com.google.inject.name.Named;
+import com.velocitypowered.api.event.Continuation;
 import com.velocitypowered.api.event.PostOrder;
 import com.velocitypowered.api.event.Subscribe;
 import com.velocitypowered.api.event.connection.DisconnectEvent;
@@ -48,7 +49,7 @@ import com.velocitypowered.api.util.GameProfile.Property;
 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.TimeUnit;
 import net.kyori.adventure.text.Component;
@@ -56,12 +57,16 @@ import org.geysermc.floodgate.api.ProxyFloodgateApi;
 import org.geysermc.floodgate.api.logger.FloodgateLogger;
 import org.geysermc.floodgate.api.player.FloodgatePlayer;
 import org.geysermc.floodgate.config.ProxyFloodgateConfig;
+import org.geysermc.floodgate.skin.SkinDataImpl;
+import org.geysermc.floodgate.util.Constants;
 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 +87,12 @@ 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 +114,9 @@ public final class VelocityListener {
     @Named("kickMessageAttribute")
     private AttributeKey<String> kickMessageAttribute;
 
+    @Inject
+    private MojangUtils mojangUtils;
+
     @Subscribe(order = PostOrder.EARLY)
     public void onPreLogin(PreLoginEvent event) {
         FloodgatePlayer player = null;
@@ -139,22 +153,38 @@ public final class VelocityListener {
     }
 
     @Subscribe(order = PostOrder.EARLY)
-    public void onGameProfileRequest(GameProfileRequestEvent event) {
+    public void onGameProfileRequest(GameProfileRequestEvent event, Continuation continuation) {
         FloodgatePlayer player = playerCache.getIfPresent(event.getConnection());
-        if (player != null) {
+        if (player == null) {
-            playerCache.invalidate(event.getConnection());
+            return;
+        }
+        playerCache.invalidate(event.getConnection());
 
-            GameProfile profile = new GameProfile(
+        // Skin look up (on Spigot and friends) would result in it failing, so apply a default skin
+        if (!player.isLinked()) {
+            event.setGameProfile(new GameProfile(
                     player.getCorrectUniqueId(),
                     player.getCorrectUsername(),
-                    Collections.emptyList()
+                    List.of(DEFAULT_TEXTURE_PROPERTY)
-            );
+            ));
-            // The texture properties addition is to fix the February 2 2022 Mojang authentication changes
+            return;
-            if (!config.isSendFloodgateData() && !player.isLinked()) {
-                profile = profile.addProperty(new Property("textures", "", ""));
-            }
-            event.setGameProfile(profile);
         }
+
+        // Floodgate players are seen as offline mode players, meaning we have to look up
+        // the linked player's textures ourselves
+
+        mojangUtils.skinFor(player.getJavaUniqueId())
+                .exceptionally(exception -> {
+                    logger.debug("Unexpected skin fetch error for " + player.getJavaUniqueId(), exception);
+                    return SkinDataImpl.DEFAULT_SKIN;
+                }).thenAccept(skin -> {
+                    event.setGameProfile(new GameProfile(
+                            player.getCorrectUniqueId(),
+                            player.getCorrectUsername(),
+                            List.of(new Property("textures", skin.value(), skin.signature()))
+                    ));
+                    continuation.resume();
+                });
     }
 
     @Subscribe(order = PostOrder.LAST)