Connection disconnect reason (#32)

- Adds disconnect packets that can be used to send the client a disconnect reason - Adds connection states. Depending on the connection state, a different kick packet is used - Adds `connection.disconnect` optional reason (sent as a kick packet) - When server is shutting down, the configured kick message is sent to all connections in a valid state. By default, `Server closed`
arciera · Aug 11, 2023 · 280f4af · 280f4af
2 parents 99a0b17 + ec58cf4
commit 280f4af
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Showing 16 changed files with 192 additions and 38 deletions.
diff --git a/config.json b/config.json
@@ -1,3 +1,4 @@
 {
-    "port": "25565"
+    "port": "25565",
+    "shutdownKickReason": "Server closed"
 }
diff --git a/index.ts b/index.ts
@@ -42,5 +42,5 @@ process.on("SIGINT", () => {
 });
 
 server.on("packet.LoginPacket", (packet, conn) => {
-    new LoginSuccessPacket(packet.data.uuid, packet.data.username).send(conn);
+    new LoginSuccessPacket(packet.data.uuid, packet.data.username).send(conn).then();
 });
diff --git a/src/Config.ts b/src/Config.ts
@@ -4,6 +4,11 @@ import Logger from "./Logger.js";
 export default class Config {
     public port: number = 25565;
 
+    /**
+     * Kick reason for when the server is shutting down
+     */
+    public shutdownKickReason: string = "Server closed";
+
     /**
      * Get a Config instance from a json file
      * @param file The file to read from

diff --git a/src/Connection.ts b/src/Connection.ts
@@ -6,7 +6,7 @@ import Packet from "./Packet.js";
 /**
  * A TCP socket connection to the server.
  */
-export default class Connection {
+class Connection {
     /**
      * A unique identifier for this connection.
      */
@@ -19,6 +19,22 @@ export default class Connection {
      * The server to which this connection belongs.
      */
     public readonly server: Server;
+    /**
+     * The state of the connection.
+     */
+    #state: Connection.State = Connection.State.NONE;
+
+    /**
+     * The state of the connection.
+     */
+    public get state(): Connection.State {
+        return this.#state;
+    }
+
+    /** @internal */
+    public _setState(state: Connection.State): void {
+        this.#state = state;
+    }
 
     /**
      * Packet fragment this connection is currently sending to the server.
@@ -37,9 +53,9 @@ export default class Connection {
         if (this.currentPacketFragment.push(data)) {
             const p = this.currentPacketFragment.getTypedClient();
             if (p) {
+                p.execute(this, this.server);
                 this.server.emit("packet", p, this);
                 this.server.emit(`packet.${p.constructor.name}` as any, p, this);
-                p.execute(this, this.server);
             }
             else this.server.emit("unknownPacket", this.currentPacketFragment, this);
             this.currentPacketFragment = new Packet();
@@ -48,9 +64,10 @@ export default class Connection {
 
     /**
      * Disconnect this connection.
+     * @param [reason] The reason for the disconnect.
      */
-    public disconnect(): Promise<boolean> {
-        return this.server.connections.disconnect(this.id);
+    public disconnect(reason?: string): Promise<boolean> {
+        return this.server.connections.disconnect(this.id, reason);
     }
 
     /**
@@ -60,3 +77,38 @@ export default class Connection {
         return !this.socket.destroyed && this.server.connections.get(this.id) !== null;
     }
 }
+
+namespace Connection {
+    /**
+     * Connection state
+     */
+    export enum State {
+        /**
+         * None / unknown
+         */
+        NONE,
+
+        /**
+         * Status state
+         *
+         * Sender is checking server status
+         */
+        STATUS,
+
+        /**
+         * Login state
+         *
+         * Player is connecting to the server
+         */
+        LOGIN,
+
+        /**
+         * Play state
+         *
+         * Player is online and communicating game data
+         */
+        PLAY
+    }
+}
+
+export default Connection;
diff --git a/src/ConnectionPool.ts b/src/ConnectionPool.ts
@@ -1,4 +1,6 @@
-import Connection from "./Connection";
+import Connection from "./Connection.js";
+import DisconnectLoginPacket from "./packet/server/DisconnectLoginPacket.js";
+import DisconnectPlayPacket from "./packet/server/DisconnectPlayPacket.js";
 
 export default class ConnectionPool {
     private readonly connections: Connection[] = [];
@@ -22,28 +24,42 @@ export default class ConnectionPool {
 
     /**
      * Disconnect all connections
+     * @param [reason] The reason for the disconnect
      * @returns Whether all connections disconnected successfully
      */
-    public async disconnect(): Promise<boolean>;
+    public async disconnectAll (reason?: string): Promise<boolean> {
+        const promises: Promise<boolean>[] = [];
+        for (const connection of this.connections)
+            promises.push(this.disconnect(connection.id, reason));
+        return (await Promise.all(promises)).every(result => result);
+    }
+
     /**
      * Disconnect a connection
      * @param id The ID of the connection to disconnect
+     * @param [reason] The reason for the disconnect
      * @returns Whether the connection was found and disconnected
      */
-    public async disconnect(id: string): Promise<boolean>;
-    public async disconnect(id?: string): Promise<boolean> {
-        const promises: Promise<boolean>[] = [];
-        if (id) {
-            const connection = this.get(id);
-            if (!connection) return false;
-            const index = this.connections.indexOf(connection);
-            if (index === -1) return false;
-            this.connections.splice(index, 1);
-            connection.server.emit("disconnect", connection);
-            promises.push(new Promise(resolve => connection.socket.end(() => resolve(true))));
+    public async disconnect(id: string, reason?: string): Promise<boolean> {
+        const connection = this.get(id);
+        if (!connection) return false;
+        const index = this.connections.indexOf(connection);
+        if (index === -1) return false;
+        if (reason) switch (connection.state) {
+            case Connection.State.LOGIN: {
+                await new DisconnectLoginPacket({text: reason}).send(connection);
+                break;
+            }
+            case Connection.State.PLAY: {
+                await new DisconnectPlayPacket({text: reason}).send(connection);
+                break;
+            }
+            default: {
+                connection.server.logger.warn("Cannot set disconnect reason for state " + Connection.State[connection.state] + " on connection " + connection.id);
+            }
         }
-        else for (const connection of this.connections)
-                promises.push(this.disconnect(connection.id));
-        return (await Promise.all(promises)).every(result => result);
+        this.connections.splice(index, 1);
+        connection.server.emit("disconnect", connection);
+        return new Promise(resolve => connection.socket.end(() => resolve(true)));
     }
 }
diff --git a/src/Packet.ts b/src/Packet.ts
@@ -1,5 +1,5 @@
 import ParsedPacket from "./ParsedPacket.js";
-import {TypedClientPacket, TypedClientPacketStatic} from "./TypedPacket";
+import {TypedClientPacket, TypedClientPacketStatic} from "./types/TypedPacket";
 import HandshakePacket from "./packet/client/HandshakePacket.js";
 import LoginPacket from "./packet/client/LoginPacket.js";
 
@@ -178,6 +178,22 @@ export default class Packet {
         return buffer;
     }
 
+    /**
+     * Parse chat
+     * @param buffer
+     */
+    public static parseChat(buffer: Buffer): ChatComponent {
+        return JSON.parse(Packet.parseString(buffer)) as ChatComponent;
+    }
+
+    /**
+     * Write chat
+     * @param value
+     */
+    public static writeChat(value: ChatComponent): Buffer {
+        return Packet.writeString(JSON.stringify(value));
+    }
+
     /**
      * Get typed client packet
      */

diff --git a/src/Server.ts b/src/Server.ts
@@ -4,8 +4,8 @@ import path from "node:path";
 import Packet from "./Packet.js";
 import Config from "./Config.js";
 import Logger from "./Logger.js";
-import {TypedClientPacket} from "./TypedPacket";
-import TypedEventEmitter from "./TypedEventEmitter";
+import {TypedClientPacket} from "./types/TypedPacket";
+import TypedEventEmitter from "./types/TypedEventEmitter";
 import ConnectionPool from "./ConnectionPool.js";
 import Connection from "./Connection.js";
 import HandshakePacket from "./packet/client/HandshakePacket";
@@ -91,8 +91,8 @@ export default class Server extends (EventEmitter as new () => TypedEventEmitter
                     else resolve(void 0);
                 });
             }),
-            this.connections.disconnect(),
-        ]).then(() => void 0);
+            this.connections.disconnectAll(this.config.shutdownKickReason),
+        ]);
         this.emit("closed");
     }
 

diff --git a/src/ServerPacket.ts b/src/ServerPacket.ts
@@ -11,7 +11,12 @@ export default abstract class ServerPacket extends Packet {
      * Send packet to a connection
      * @param connection
      */
-    public send(connection: Connection): void {
-        connection.socket.write(this.dataBuffer);
+    public send(connection: Connection): Promise<void> {
+        return new Promise((resolve, reject) => {
+            connection.socket.write(this.dataBuffer, (err) => {
+                if (err) reject(err);
+                else resolve();
+            });
+        });
     }
 }
diff --git a/src/packet/client/HandshakePacket.ts b/src/packet/client/HandshakePacket.ts
@@ -1,8 +1,8 @@
-import {TypedClientPacket, TypedClientPacketStatic} from "../../TypedPacket";
+import {TypedClientPacket, TypedClientPacketStatic} from "../../types/TypedPacket";
 import StaticImplements from "../../decorator/StaticImplements.js";
 import Server from "../../Server";
 import ParsedPacket from "../../ParsedPacket";
-import Connection from "../../Connection";
+import Connection from "../../Connection.js";
 
 @StaticImplements<TypedClientPacketStatic>()
 export default class HandshakePacket {
@@ -25,7 +25,9 @@ export default class HandshakePacket {
         } as const;
     }
 
-    execute(_conn: Connection, _server: Server): void {}
+    execute(conn: Connection, _server: Server): void {
+        conn._setState(Connection.State.LOGIN);
+    }
 
     public static readonly id = 0x00;
 

diff --git a/src/packet/client/LoginPacket.ts b/src/packet/client/LoginPacket.ts
@@ -1,8 +1,8 @@
-import {TypedClientPacket, TypedClientPacketStatic} from "../../TypedPacket";
+import {TypedClientPacket, TypedClientPacketStatic} from "../../types/TypedPacket";
 import StaticImplements from "../../decorator/StaticImplements.js";
 import ParsedPacket from "../../ParsedPacket.js";
 import Server from "../../Server";
-import Connection from "../../Connection";
+import Connection from "../../Connection.js";
 
 @StaticImplements<TypedClientPacketStatic>()
 export default class LoginPacket {
@@ -24,7 +24,9 @@ export default class LoginPacket {
         }
     }
 
-    execute(_conn: Connection, _server: Server): void {}
+    execute(conn: Connection, _server: Server): void {
+        conn._setState(Connection.State.LOGIN);
+    }
 
     public static readonly id = 0x00;
 

diff --git a/src/packet/server/DisconnectLoginPacket.ts b/src/packet/server/DisconnectLoginPacket.ts
@@ -0,0 +1,12 @@
+import ServerPacket from "../../ServerPacket.js";
+
+export default class DisconnectLoginPacket extends ServerPacket {
+    public static readonly id = 0x00;
+
+    public constructor(reason: ChatComponent) {
+        super(Buffer.concat([
+            ServerPacket.writeVarInt(DisconnectLoginPacket.id),
+            ServerPacket.writeChat(reason)
+        ]));
+    }
+}
diff --git a/src/packet/server/DisconnectPlayPacket.ts b/src/packet/server/DisconnectPlayPacket.ts
@@ -0,0 +1,12 @@
+import ServerPacket from "../../ServerPacket.js";
+
+export default class DisconnectPlayPacket extends ServerPacket {
+    public static readonly id = 0x1a;
+
+    public constructor(reason: ChatComponent) {
+        super(Buffer.concat([
+            ServerPacket.writeVarInt(DisconnectPlayPacket.id),
+            ServerPacket.writeChat(reason)
+        ]));
+    }
+}
diff --git a/src/packet/server/LoginSuccessPacket.ts b/src/packet/server/LoginSuccessPacket.ts
@@ -1,4 +1,5 @@
 import ServerPacket from "../../ServerPacket.js";
+import Connection from "../../Connection.js";
 
 /**
  * A Minecraft protocol client-bound LoginSuccess packet.
@@ -14,4 +15,9 @@ export default class LoginSuccessPacket extends ServerPacket {
             ServerPacket.writeVarInt(0)
         ]));
     }
+
+    public override send(connection: Connection) {
+        connection._setState(Connection.State.PLAY);
+        return super.send(connection);
+    }
 }
diff --git a/src/types/ChatComponent.ts b/src/types/ChatComponent.ts
@@ -0,0 +1,25 @@
+type ChatComponent = {
+    bold?: boolean;
+    italic?: boolean;
+    underlined?: boolean;
+    strikethrough?: boolean;
+    obfuscated?: boolean;
+    font?: string;
+    color?: string;
+    insertion?: string;
+    clickEvent?: {
+        action: "open_url" | "open_file" | "run_command" | "suggest_command" | "change_page" | "copy_to_clipboard";
+        value: string;
+    }
+    hoverEvent?: {
+        action: "show_text" | "show_item" | "show_entity";
+    }
+    text?: string;
+    extra?: [ChatComponent, ...ChatComponent[]];
+} | {translate: string; with?: ChatComponent[]} | {keybind: string} | {
+    score: {
+        name: string;
+        objective: string;
+        value?: string;
+    }
+};
diff --git a/src/TypedEventEmitter.ts → src/types/TypedEventEmitter.ts b/src/TypedEventEmitter.ts → src/types/TypedEventEmitter.ts
diff --git a/src/TypedPacket.ts → src/types/TypedPacket.ts b/src/TypedPacket.ts → src/types/TypedPacket.ts
@@ -1,6 +1,6 @@
-import Server from "./Server";
-import ParsedPacket from "./ParsedPacket";
-import Connection from "./Connection";
+import Server from "../Server";
+import ParsedPacket from "../ParsedPacket";
+import Connection from "../Connection";
 
 export interface TypedClientPacket {
     readonly packet: ParsedPacket;