Add GeyserBedrockPingEvent (#3715)

api/src/main/java/org/geysermc/geyser/api/event/connection/GeyserBedrockPingEvent.java

@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2019-2023 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/Geyser
+ */
+
+package org.geysermc.geyser.api.event.connection;
+
+import org.checkerframework.checker.index.qual.NonNegative;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.geysermc.event.Event;
+
+import java.net.InetSocketAddress;
+
+/**
+ * Called whenever Geyser gets pinged
+ *
+ * This event allows you to modify/obtain the MOTD, maximum player count, and current number of players online,
+ * Geyser will reply to the client with what was given.
+ */
+public interface GeyserBedrockPingEvent extends Event {
+
+    /**
+     * Sets the given string as the primary motd, the given string cannot be null.
+     *
+     * @param primary the string to set as the primary motd
+     */
+    void primaryMotd(@NonNull String primary);
+
+    /**
+     * Sets the given string as the secondary motd, the given string cannot be null.
+     * Note: the secondary motd is only used for the LAN game entry.
+     *
+     * @param secondary the string to set as the secondary motd
+     */
+    void secondaryMotd(@NonNull String secondary);
+
+    /**
+     * Sets how many players are currently online, the given number cannot be below 0.
+     *
+     * @param count the number to set
+     */
+    void playerCount(int count);
+
+    /**
+     * Sets the maximum number of players that can join this server, the given number cannot be below 1.
+     *
+     * @param max the number to set
+     */
+    void maxPlayerCount(int max);
+
+    /**
+     * Gets the primary motd.
+     *
+     * @return the primary motd string
+     */
+    @Nullable
+    String primaryMotd();
+
+    /**
+     * Gets the secondary motd.
+     *
+     * @return the secondary motd string
+     */
+    @Nullable
+    String secondaryMotd();
+
+    /**
+     * Gets the current number of players.
+     *
+     * @return number of players online
+     */
+    @NonNegative
+    int playerCount();
+
+    /**
+     * Gets the maximum number of players that can join this server
+     *
+     * @return maximum number of players that can join
+     */
+    int maxPlayerCount();
+
+    /**
+     * Gets the {@link InetSocketAddress} of the client pinging us.
+     *
+     * @return a {@link InetSocketAddress}
+     */
+    @NonNull
+    InetSocketAddress address();
+}

core/src/main/java/org/geysermc/geyser/event/type/GeyserBedrockPingEventImpl.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2019-2023 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/Geyser
+ */
+
+package org.geysermc.geyser.event.type;
+
+import org.checkerframework.checker.index.qual.NonNegative;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.cloudburstmc.protocol.bedrock.BedrockPong;
+import org.geysermc.geyser.api.event.connection.GeyserBedrockPingEvent;
+import org.jetbrains.annotations.NotNull;
+
+import javax.annotation.Nonnull;
+import java.net.InetSocketAddress;
+import java.util.Objects;
+
+public class GeyserBedrockPingEventImpl implements GeyserBedrockPingEvent {
+    private final InetSocketAddress address;
+    private final BedrockPong pong;
+
+    public GeyserBedrockPingEventImpl(BedrockPong pong, InetSocketAddress address) {
+        this.address = address;
+        this.pong = pong;
+    }
+
+    @Override
+    public void primaryMotd(@Nonnull String primary) {
+        pong.motd(Objects.requireNonNull(primary, "Primary MOTD cannot be null"));
+    }
+
+    @Override
+    public void secondaryMotd(@Nonnull String secondary) {
+        pong.subMotd(Objects.requireNonNull(secondary, "Secondary MOTD cannot be null"));
+    }
+
+    @Override
+    public void playerCount(int count) {
+        if (count < 0) throw new IllegalArgumentException("Player count cannot be below 0");
+        pong.playerCount(count);
+    }
+
+    @Override
+    public void maxPlayerCount(int max) {
+        if (max < 1) throw new IllegalArgumentException("Max player count cannot be below 1");
+        pong.maximumPlayerCount(max);
+    }
+
+    @Override
+    public @Nullable String primaryMotd() {
+        return pong.motd();
+    }
+
+    @Override
+    public @Nullable String secondaryMotd() {
+        return pong.subMotd();
+    }
+
+    @Override
+    public @NonNegative int playerCount() {
+        return pong.playerCount();
+    }
+
+    @Override
+    public int maxPlayerCount() {
+        return pong.maximumPlayerCount();
+    }
+
+    @Override
+    public @NotNull InetSocketAddress address() {
+        return address;
+    }
+}

core/src/main/java/org/geysermc/geyser/network/netty/GeyserServer.java

@@ -48,6 +48,7 @@ import org.cloudburstmc.netty.handler.codec.raknet.server.RakServerOfflineHandle
 import org.cloudburstmc.protocol.bedrock.BedrockPong;
 import org.geysermc.geyser.GeyserImpl;
 import org.geysermc.geyser.configuration.GeyserConfiguration;
+import org.geysermc.geyser.event.type.GeyserBedrockPingEventImpl;
 import org.geysermc.geyser.network.CIDRMatcher;
 import org.geysermc.geyser.network.GameProtocol;
 import org.geysermc.geyser.network.GeyserServerInitializer;
@@ -220,6 +221,17 @@ public final class GeyserServer {
             pong.subMotd(config.getBedrock().secondaryMotd());
         }
 
+        // Placed here to prevent overriding values set in the ping event.
+        if (config.isPassthroughPlayerCounts() && pingInfo != null) {
+            pong.playerCount(pingInfo.getPlayers().getOnline());
+            pong.maximumPlayerCount(pingInfo.getPlayers().getMax());
+        } else {
+            pong.playerCount(geyser.getSessionManager().getSessions().size());
+            pong.maximumPlayerCount(config.getMaxPlayers());
+        }
+
+        this.geyser.eventBus().fire(new GeyserBedrockPingEventImpl(pong, inetSocketAddress));
+
         // https://github.com/GeyserMC/Geyser/issues/3388
         pong.motd(pong.motd().replace(';', ':'));
         pong.subMotd(pong.subMotd().replace(';', ':'));
@@ -251,14 +263,6 @@ public final class GeyserServer {
             }
         }
 
-        if (config.isPassthroughPlayerCounts() && pingInfo != null) {
-            pong.playerCount(pingInfo.getPlayers().getOnline());
-            pong.maximumPlayerCount(pingInfo.getPlayers().getMax());
-        } else {
-            pong.playerCount(geyser.getSessionManager().getSessions().size());
-            pong.maximumPlayerCount(config.getMaxPlayers());
-        }
-
         //Bedrock will not even attempt a connection if the client thinks the server is full
         //so we have to fake it not being full
         if (pong.playerCount() >= pong.maximumPlayerCount()) {