Add SessionJoinEvent and SessionLoginEvent (#3840)

api/src/main/java/org/geysermc/geyser/api/event/bedrock/SessionJoinEvent.java

@@ -0,0 +1,39 @@
+/*
+ * 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.bedrock;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.geysermc.geyser.api.connection.GeyserConnection;
+import org.geysermc.geyser.api.event.connection.ConnectionEvent;
+
+/**
+ * Called when Geyser session connected to a Java remote server and is in a play-ready state.
+ */
+public final class SessionJoinEvent extends ConnectionEvent {
+    public SessionJoinEvent(@NonNull GeyserConnection connection) {
+        super(connection);
+    }
+}

api/src/main/java/org/geysermc/geyser/api/event/bedrock/SessionLoginEvent.java

@@ -0,0 +1,109 @@
+/*
+ * 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.bedrock;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.geysermc.event.Cancellable;
+import org.geysermc.geyser.api.connection.GeyserConnection;
+import org.geysermc.geyser.api.event.connection.ConnectionEvent;
+import org.geysermc.geyser.api.network.RemoteServer;
+
+/**
+ * Called when a session has logged in, and is about to connect to a remote java server.
+ * This event is cancellable, and can be used to prevent the player from connecting to the remote server.
+ */
+public final class SessionLoginEvent extends ConnectionEvent implements Cancellable {
+    private RemoteServer remoteServer;
+    private boolean cancelled;
+    private String disconnectReason;
+
+    public SessionLoginEvent(@NonNull GeyserConnection connection, @NonNull RemoteServer remoteServer) {
+        super(connection);
+        this.remoteServer = remoteServer;
+    }
+
+    /**
+     * Returns whether the event is cancelled.
+     *
+     * @return The cancel status of the event.
+     */
+    @Override
+    public boolean isCancelled() {
+        return this.cancelled;
+    }
+
+    /**
+     * Cancels the login event, and disconnects the player.
+     * If cancelled, the player disconnects without connecting to the remote server.
+     * This method will use a default disconnect reason. To specify one, use {@link #setCancelled(boolean, String)}.
+     *
+     * @param cancelled If the login event should be cancelled.
+     */
+    @Override
+    public void setCancelled(boolean cancelled) {
+        this.cancelled = cancelled;
+    }
+
+    /**
+     * Cancels the login event, and disconnects the player with the specified reason.
+     * If cancelled, the player disconnects without connecting to the remote server.
+     *
+     * @param cancelled If the login event should be cancelled.
+     * @param disconnectReason The reason for the cancellation.
+     */
+    public void setCancelled(boolean cancelled, @NonNull String disconnectReason) {
+        this.cancelled = cancelled;
+        this.disconnectReason = disconnectReason;
+    }
+
+    /**
+     * Returns the reason for the cancellation, or null if there is no reason given.
+     *
+     * @return The reason for the cancellation.
+     */
+    public @Nullable String disconnectReason() {
+        return this.disconnectReason;
+    }
+
+    /**
+     * Gets the {@link RemoteServer} the section will attempt to connect to.
+     *
+     * @return the {@link RemoteServer} the section will attempt to connect to.
+     */
+    public @NonNull RemoteServer remoteServer() {
+        return this.remoteServer;
+    }
+
+    /**
+     * Sets the {@link RemoteServer} to connect the session to.
+     *
+     * @param remoteServer Sets the {@link RemoteServer} to connect to.
+     */
+    public void remoteServer(@NonNull RemoteServer remoteServer) {
+        this.remoteServer = remoteServer;
+    }
+}

core/src/main/java/org/geysermc/geyser/session/GeyserSession.java

@@ -56,7 +56,11 @@ import com.github.steveice10.mc.protocol.packet.ingame.serverbound.player.Server
 import com.github.steveice10.mc.protocol.packet.login.serverbound.ServerboundCustomQueryPacket;
 import com.github.steveice10.packetlib.BuiltinFlags;
 import com.github.steveice10.packetlib.Session;
-import com.github.steveice10.packetlib.event.session.*;
+import com.github.steveice10.packetlib.event.session.ConnectedEvent;
+import com.github.steveice10.packetlib.event.session.DisconnectedEvent;
+import com.github.steveice10.packetlib.event.session.PacketErrorEvent;
+import com.github.steveice10.packetlib.event.session.PacketSendingEvent;
+import com.github.steveice10.packetlib.event.session.SessionAdapter;
 import com.github.steveice10.packetlib.packet.Packet;
 import com.github.steveice10.packetlib.tcp.TcpClientSession;
 import com.github.steveice10.packetlib.tcp.TcpSession;
@@ -82,6 +86,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 import org.checkerframework.common.value.qual.IntRange;
 import org.cloudburstmc.math.vector.*;
 import org.cloudburstmc.nbt.NbtMap;
+import org.cloudburstmc.protocol.bedrock.BedrockDisconnectReasons;
 import org.cloudburstmc.protocol.bedrock.BedrockServerSession;
 import org.cloudburstmc.protocol.bedrock.data.*;
 import org.cloudburstmc.protocol.bedrock.data.command.CommandEnumData;
@@ -104,6 +109,7 @@ import org.geysermc.geyser.GeyserImpl;
 import org.geysermc.geyser.api.connection.GeyserConnection;
 import org.geysermc.geyser.api.entity.type.GeyserEntity;
 import org.geysermc.geyser.api.entity.type.player.GeyserPlayerEntity;
+import org.geysermc.geyser.api.event.bedrock.SessionLoginEvent;
 import org.geysermc.geyser.api.network.AuthType;
 import org.geysermc.geyser.api.network.RemoteServer;
 import org.geysermc.geyser.command.GeyserCommandSource;
@@ -879,6 +885,16 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
      * After getting whatever credentials needed, we attempt to join the Java server.
      */
     private void connectDownstream() {
+        SessionLoginEvent loginEvent = new SessionLoginEvent(this, remoteServer);
+        GeyserImpl.getInstance().eventBus().fire(loginEvent);
+        if (loginEvent.isCancelled()) {
+            String disconnectReason = loginEvent.disconnectReason() == null ?
+                    BedrockDisconnectReasons.DISCONNECTED : loginEvent.disconnectReason();
+            disconnect(disconnectReason);
+            return;
+        }
+
+        this.remoteServer = loginEvent.remoteServer();
         boolean floodgate = this.remoteServer.authType() == AuthType.FLOODGATE;
 
         // Start ticking

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/BedrockSetLocalPlayerAsInitializedTranslator.java

@@ -26,6 +26,8 @@
 package org.geysermc.geyser.translator.protocol.bedrock;
 
 import org.cloudburstmc.protocol.bedrock.packet.SetLocalPlayerAsInitializedPacket;
+import org.geysermc.geyser.GeyserImpl;
+import org.geysermc.geyser.api.event.bedrock.SessionJoinEvent;
 import org.geysermc.geyser.api.network.AuthType;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
@@ -68,6 +70,8 @@ public class BedrockSetLocalPlayerAsInitializedTranslator extends PacketTranslat
 
                     // What am I to expect - as of Bedrock 1.18
                     session.getFormCache().resendAllForms();
+
+                    GeyserImpl.getInstance().eventBus().fire(new SessionJoinEvent(session));
                 }
             }
         }