From 49a993786c6435cc17780241dd205a2ca1a818a2 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Tue, 7 Jan 2020 15:34:57 +0100
Subject: Add TCP interface

Supports password protection
---
 .../taskmanager/network/NetworkHandlerTcp.java     | 193 +++++++++++++++++++++
 1 file changed, 193 insertions(+)
 create mode 100644 daemon/src/main/java/org/openslx/taskmanager/network/NetworkHandlerTcp.java

(limited to 'daemon/src/main/java/org/openslx/taskmanager/network/NetworkHandlerTcp.java')

diff --git a/daemon/src/main/java/org/openslx/taskmanager/network/NetworkHandlerTcp.java b/daemon/src/main/java/org/openslx/taskmanager/network/NetworkHandlerTcp.java
new file mode 100644
index 0000000..e37b3d7
--- /dev/null
+++ b/daemon/src/main/java/org/openslx/taskmanager/network/NetworkHandlerTcp.java
@@ -0,0 +1,193 @@
+package org.openslx.taskmanager.network;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.SynchronousQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.log4j.Logger;
+import org.openslx.taskmanager.Global;
+
+/**
+ * The network listener that will receive incoming UDP packets, try to process
+ * them, and then send a reply.
+ */
+public class NetworkHandlerTcp extends NetworkHandlerBase
+{
+
+	private static final Logger log = Logger.getLogger( NetworkHandlerTcp.class );
+
+	/**
+	 * UDP socket for sending and receiving.
+	 */
+	private final ServerSocket socket;
+
+	private final ThreadPoolExecutor threadPool = new ThreadPoolExecutor( 1, 8, 1, TimeUnit.MINUTES, new SynchronousQueue<Runnable>() );
+
+	/**
+	 * Initialize the NetworkHandler by starting threads and opening the socket.
+	 */
+	public NetworkHandlerTcp( int port, InetAddress listenAddress, RequestParser parser ) throws IOException
+	{
+		super( parser );
+		socket = new ServerSocket( port, 10, listenAddress );
+		log.info( "Listening on TCP:" + port );
+		threadPool.setRejectedExecutionHandler( new ThreadPoolExecutor.AbortPolicy() );
+	}
+
+	public void shutdown()
+	{
+		try {
+			socket.close();
+		} catch ( IOException e ) {
+		}
+	}
+
+	/**
+	 * Main loop of receiving thread - wait until a packet arrives, then try to handle/decode
+	 */
+	@Override
+	public void run()
+	{
+		try {
+			while ( !Global.doShutdown ) {
+				Socket client;
+				try {
+					client = socket.accept();
+				} catch ( IOException e1 ) {
+					log.warn( "ACCEPT fail", e1 );
+					break;
+				}
+				try {
+					threadPool.execute( new ClientTask( client ) );
+				} catch ( RejectedExecutionException e ) {
+					try {
+						client.close();
+					} catch ( IOException e1 ) {
+					}
+				}
+			}
+		} finally {
+			Thread.currentThread().interrupt();
+			Global.doShutdown = true;
+			log.info( "UDP receiver finished." );
+		}
+	}
+
+	private class ClientTask implements Runnable
+	{
+		private final Socket socket;
+		private DataOutputStream writer = null;
+		private DataInputStream reader = null;
+			
+		public ClientTask( Socket client )
+		{
+			this.socket = client;
+		}
+
+		@Override
+		public void run()
+		{
+			try {
+				try {
+					socket.setSoTimeout( (int)TimeUnit.MINUTES.toMillis( 15 ) );
+					reader = new DataInputStream( socket.getInputStream() );
+					writer = new DataOutputStream( socket.getOutputStream() );
+				} catch ( IOException e ) {
+					log.info( "IOException on TCP socket when setting up streams", e );
+					return;
+				}
+				String payload = readMsg( reader );
+				if ( payload == null )
+					return;
+				int i = payload.indexOf( ' ' );
+				if ( i != -1 ) {
+					// For future extensibility we throw away everything after the first space (including the space)
+					payload = payload.substring( 0, i );
+				}
+				if ( !payload.equals( Global.PASSWORD ) ) {
+					sendMsg( "ERROR,Wrong password" );
+					return;
+				}
+				while ( !socket.isClosed() ) {
+					payload = readMsg( reader );
+					if ( payload == null )
+						return;
+					byte[] reply;
+					try {
+						reply = parser.handle( payload );
+					} catch ( Throwable t ) {
+						log.error( "Exception in RequestParser", t );
+						log.error( "Payload was: " + payload );
+						continue;
+					}
+					if ( reply != null ) {
+						sendMsg( reply );
+					}
+				}
+			} catch ( SendException e ) {
+				log.warn( "Cannot send reply to client", e );
+			} finally {
+				try {
+					if ( writer != null ) {
+						writer.flush();
+						writer.close();
+					}
+					socket.close();
+				} catch ( IOException e ) {
+				}
+			}
+		}
+		
+		private void sendMsg( String reply ) throws SendException
+		{
+			sendMsg( reply.getBytes( StandardCharsets.UTF_8 ) );
+		}
+
+		private void sendMsg( byte[] reply ) throws SendException
+		{
+			try {
+				writer.writeInt( reply.length );
+				writer.write( reply );
+			} catch ( IOException e ) {
+				throw new SendException();
+			}
+		}
+
+		private String readMsg( DataInputStream reader )
+		{
+			int bytes;
+			try {
+				bytes = reader.readInt();
+			} catch ( IOException e ) {
+				// This should be fine... Client went away
+				return null;
+			}
+			if ( bytes < 0 || bytes > Global.MAX_REQUEST_SIZE ) {
+				log.info( "Invalid request size: " + bytes );
+				return null;
+			}
+			if ( bytes == 0 )
+				return ""; // Nothing to read
+			byte[] buffer = new byte[ bytes ];
+			try {
+				reader.readFully( buffer );
+			} catch ( IOException e ) {
+				log.warn( "Client went away when trying to read payload" );
+				return null;
+			}
+			return new String( buffer, StandardCharsets.UTF_8 );
+		} 
+
+	}
+	
+	private static class SendException extends Exception {}
+
+}
-- 
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