Added support for multiple client connections to BNLS

Added support for multiple client connections to BNLS
Added support for ConnectionClosed packet to politely close connection

core/src/com/riiablo/net/bnls/BNLS.fbs

@@ -1,8 +1,10 @@
+include "ConnectionClosed.fbs";
 include "QueryRealms.fbs";
 
 namespace com.riiablo.net.packet.bnls;
 
 union BNLSData {
+  ConnectionClosed,
   QueryRealms,
 }
 

core/src/com/riiablo/net/bnls/ConnectionClosed.fbs

@@ -0,0 +1,5 @@
+namespace com.riiablo.net.packet.bnls;
+
+table ConnectionClosed {
+  reason:string;
+}

server/src/com/riiablo/server/BNLS.java

@@ -7,10 +7,12 @@ import com.badlogic.gdx.Gdx;
 import com.badlogic.gdx.Net;
 import com.badlogic.gdx.backends.headless.HeadlessApplication;
 import com.badlogic.gdx.backends.headless.HeadlessApplicationConfiguration;
+import com.badlogic.gdx.math.MathUtils;
 import com.badlogic.gdx.net.ServerSocket;
 import com.badlogic.gdx.net.Socket;
 import com.badlogic.gdx.utils.BufferUtils;
 import com.riiablo.net.packet.bnls.BNLSData;
+import com.riiablo.net.packet.bnls.ConnectionClosed;
 import com.riiablo.net.packet.bnls.QueryRealms;
 import com.riiablo.net.packet.bnls.Realm;
 
@@ -26,12 +28,14 @@ import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
 import java.text.DateFormat;
 import java.util.Calendar;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 public class BNLS extends ApplicationAdapter {
   private static final String TAG = "BNLS";
 
   private static final int PORT = 6110;
+  private static final int MAX_CLIENTS = 32;
 
   public static void main(String[] args) {
     HeadlessApplicationConfiguration config = new HeadlessApplicationConfiguration();
@@ -40,9 +44,11 @@ public class BNLS extends ApplicationAdapter {
 
   ServerSocket server;
   ByteBuffer buffer;
-  Thread thread;
+  Thread main;
   AtomicBoolean kill;
   Thread cli;
+  ThreadGroup clientThreads;
+  CopyOnWriteArrayList<Client> CLIENTS = new CopyOnWriteArrayList<>();
 
   private static final String[][] REALMS = new String[][] {
       {"localhost", "U.S. West"},
@@ -65,42 +71,43 @@ public class BNLS extends ApplicationAdapter {
       Gdx.app.error(TAG, e.getMessage(), e);
     }
 
+    clientThreads = new ThreadGroup("BNLSClients");
+
     Gdx.app.log(TAG, "Starting server...");
     server = Gdx.net.newServerSocket(Net.Protocol.TCP, PORT, null);
     buffer = BufferUtils.newByteBuffer(4096);
     kill = new AtomicBoolean(false);
-    thread = new Thread(new Runnable() {
+    main = new Thread(new Runnable() {
       @Override
       public void run() {
         while (!kill.get()) {
-          Socket socket = null;
+          Gdx.app.log(TAG, "waiting...");
-          try {
+          Socket socket = server.accept(null);
-            Gdx.app.log(TAG, "waiting...");
+          Gdx.app.log(TAG, "connection from " + socket.getRemoteAddress());
-            socket = server.accept(null);
+          if (CLIENTS.size() >= MAX_CLIENTS) {
-            Gdx.app.log(TAG, "connection from " + socket.getRemoteAddress());
+            try {
+              ConnectionDenied(socket, "Server is Full");
+            } catch (Throwable ignored) {
+            } finally {
+              socket.dispose();
+            }
+          } else {
+            new Client(socket).start();
+          }
+        }
 
-            buffer.mark();
+        Gdx.app.log(TAG, "killing child threads...");
-            ReadableByteChannel in = Channels.newChannel(socket.getInputStream());
+        for (Client client : CLIENTS) {
-            in.read(buffer);
+          if (client != null) {
-            buffer.limit(buffer.position());
+            client.kill.set(true);
-            buffer.reset();
-
-            com.riiablo.net.packet.bnls.BNLS packet = com.riiablo.net.packet.bnls.BNLS.getRootAsBNLS(buffer);
-            Gdx.app.log(TAG, "packet type " + BNLSData.name(packet.dataType()));
-            process(socket, packet);
-          } catch (Throwable t) {
-            Gdx.app.log(TAG, t.getMessage());
-          } finally {
-            Gdx.app.log(TAG, "closing socket...");
-            if (socket != null) socket.dispose();
           }
         }
 
         Gdx.app.log(TAG, "killing thread...");
       }
     });
-    thread.setName("BNLS");
+    main.setName("BNLS");
-    thread.start();
+    main.start();
 
     cli = new Thread(new Runnable() {
       @Override
@@ -134,7 +141,7 @@ public class BNLS extends ApplicationAdapter {
     kill.set(true);
     server.dispose();
     try {
-      thread.join();
+      main.join();
     } catch (Throwable ignored) {}
   }
 
@@ -148,7 +155,21 @@ public class BNLS extends ApplicationAdapter {
     }
   }
 
-  private void QueryRealms(Socket socket) throws IOException {
+  private boolean ConnectionDenied(Socket socket, String reason) throws IOException {
+    FlatBufferBuilder builder = new FlatBufferBuilder();
+    int reasonOffset = builder.createString(reason);
+    int connectionDeniedId = ConnectionClosed.createConnectionClosed(builder, reasonOffset);
+    int id = com.riiablo.net.packet.bnls.BNLS.createBNLS(builder, BNLSData.ConnectionClosed, connectionDeniedId);
+    builder.finish(id);
+
+    ByteBuffer data = builder.dataBuffer();
+    OutputStream out = socket.getOutputStream();
+    WritableByteChannel channel = Channels.newChannel(out);
+    channel.write(data);
+    return true;
+  }
+
+  private boolean QueryRealms(Socket socket) throws IOException {
     FlatBufferBuilder builder = new FlatBufferBuilder();
 
     int[] realms = new int[REALMS.length];
@@ -171,5 +192,42 @@ public class BNLS extends ApplicationAdapter {
     WritableByteChannel channel = Channels.newChannel(out);
     channel.write(data);
     Gdx.app.log(TAG, "returning realms list...");
+    return false;
+  }
+
+  static String generateClientName() {
+    return String.format("Client-%08X", MathUtils.random(1, Integer.MAX_VALUE - 1));
+  }
+
+  private class Client extends Thread {
+    Socket socket;
+    AtomicBoolean kill = new AtomicBoolean(false);
+
+    Client(Socket socket) {
+      super(clientThreads, generateClientName());
+      this.socket = socket;
+    }
+
+    @Override
+    public void run() {
+      while (!kill.get()) {
+        try {
+          buffer.mark();
+          ReadableByteChannel in = Channels.newChannel(socket.getInputStream());
+          in.read(buffer);
+          buffer.limit(buffer.position());
+          buffer.reset();
+
+          com.riiablo.net.packet.bnls.BNLS packet = com.riiablo.net.packet.bnls.BNLS.getRootAsBNLS(buffer);
+          Gdx.app.log(TAG, "packet type " + BNLSData.name(packet.dataType()));
+          process(socket, packet);
+        } catch (Throwable t) {
+          Gdx.app.log(TAG, t.getMessage());
+        } finally {
+          Gdx.app.log(TAG, "closing socket...");
+          if (socket != null) socket.dispose();
+        }
+      }
+    }
   }
 }

server/test/com/riiablo/server/BNLSTest.java

@@ -60,7 +60,12 @@ public class BNLSTest {
       buffer.rewind();
 
       com.riiablo.net.packet.bnls.BNLS packet = com.riiablo.net.packet.bnls.BNLS.getRootAsBNLS(buffer);
-      Gdx.app.log(TAG, "packet " + packet.dataType());
+      Gdx.app.log(TAG, "packet " + BNLSData.name(packet.dataType()));
+
+      if (packet.dataType() == BNLSData.ConnectionClosed) {
+        Gdx.app.log(TAG, "connection closed.");
+        return;
+      }
 
       QueryRealms qr = (QueryRealms) packet.data(new QueryRealms());
       Gdx.app.log(TAG, "realms:");