Finished (hopefully)
parent
9c9647b992
commit
e7c4f781a2
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@ -5,37 +5,94 @@ import java.net.DatagramPacket;
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import java.net.DatagramSocket;
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import java.net.InetAddress;
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import java.net.SocketAddress;
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import java.util.ArrayList;
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import javax.print.attribute.standard.Severity;
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import vs.AsciiChars.L032;
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import vs.AsciiChars.L048;
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import vs.AsciiChars.L128;
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import vs.AsciiChars.L255;
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import vs.SyslogMessage.Facility;
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import vs.SyslogMessage.TextMessage;
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public class Client {
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private static final int BUFSIZE = 512;
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private static final String BROADCAST_ADDRESS = "255.255.255.255";
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private static final int DISCOVERY_PORT = 8888;
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private static final int SYSLOG_PORT = 514;
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static DatagramPacket packetOutDisover = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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static DatagramPacket packetInOffer = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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static DatagramPacket packetOutRequest = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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static DatagramPacket packetInAcknowledge = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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static DatagramPacket packetOutSyslog = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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public static void main(String[] args) {
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try (DatagramSocket socket = new DatagramSocket()) {
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socket.setBroadcast(true);
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//? Get Server IP
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String message = "DISCOVER_SERVERS";
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byte[] buffer = message.getBytes();
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//? SEND DISOVERY
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String messageString = "DISCOVER";
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byte[] message = messageString.getBytes();
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InetAddress broadcastAddress = InetAddress.getByName("255.255.255.255");
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int discoveryPort = 8888;
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packetOutDisover.setAddress(InetAddress.getByName(BROADCAST_ADDRESS));
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packetOutDisover.setPort(DISCOVERY_PORT);
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packetOutDisover.setData(message);
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packetOutDisover.setLength(message.length);
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DatagramPacket packetOutDisover = new DatagramPacket(buffer, buffer.length, broadcastAddress, discoveryPort);
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socket.send(packetOutDisover);
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//? Got server IP
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DatagramPacket packetIn = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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socket.receive(packetIn);
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//? GET OFFER + SEND REQUEST
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socket.receive(packetInOffer);
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String receivedOffer = new String(packetInOffer.getData(), 0, packetInOffer.getLength());
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System.out.println("Received Offer: " + receivedOffer);
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messageString = "REQUEST";
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message = messageString.getBytes();
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System.out.println("Recieved Server IP " + packetIn.getSocketAddress());
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packetOutRequest.setAddress(packetInOffer.getAddress());
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packetOutRequest.setPort(DISCOVERY_PORT);
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packetOutRequest.setData(message);
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packetOutRequest.setLength(message.length);
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socket.send(packetOutRequest);
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//? GET ACKNOWLEDGE
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socket.receive(packetInAcknowledge);
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String receivedAckowledge = new String(packetInAcknowledge.getData(), 0, packetInAcknowledge.getLength());
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System.out.println("Received Acknowledge: " + receivedAckowledge);
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InetAddress syslogServerAddress = packetInAcknowledge.getAddress();
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//? SEND SYSLOG
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System.out.println("Recieved Server IP " + syslogServerAddress);
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DatagramPacket packetOutSyslog = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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packetOutSyslog.setAddress(packetIn.getAddress());
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int syslogPort = 514;
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packetOutSyslog.setPort(syslogPort);
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packetOutSyslog.setAddress(syslogServerAddress);
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packetOutSyslog.setPort(SYSLOG_PORT);
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TextMessage textMessage = new TextMessage("message");
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SyslogMessage syslogMessage = new SyslogMessage(
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SyslogMessage.Facility.USER,
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SyslogMessage.Severity.INFORMATIONAL,
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new L255("192.168.2.100"),
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new L048("java"),
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new L128("1"),
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new L032("1"),
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new StructuredData(new ArrayList<>()),
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textMessage
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);
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String syslogMessage = formatSyslogMessage(message);
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byte[] syslogMessageBytes = syslogMessage.getBytes();
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String syslogMessageString = syslogMessage.toString();
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byte[] syslogMessageBytes = syslogMessageString.getBytes();
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packetOutSyslog.setData(syslogMessageBytes);
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packetOutSyslog.setLength(syslogMessageBytes.length);
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@ -48,23 +105,4 @@ public class Client {
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e.printStackTrace();
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}
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}
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private static String formatSyslogMessage(String message) {
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// Basic RFC 5424 format without structured data
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// <PRI>TIMESTAMP HOSTNAME APPNAME PID MESSAGEID [STRUCTURED-DATA] MSG
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// Since you ignore structured data, we skip that part
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int facility = 16; // local0
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int severity = 6; // informational
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int pri = (facility * 8) + severity;
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String timestamp = java.time.Instant.now().toString();
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String hostname = "test-client";
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String appName = "SyslogTest";
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String procId = "12345";
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String msgId = "TEST001";
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return String.format("<%d>1 %s %s %s %s %s - %s",
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pri, timestamp, hostname, appName, procId, msgId, message);
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}
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}
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@ -4,11 +4,12 @@ import java.net.DatagramPacket;
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import java.net.DatagramSocket;
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import java.net.InetAddress;
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// Discovery-Responder (ähnlich DHCP-Verhalten, aber minimal):
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// - Hört auf UDP/8888 und akzeptiert Broadcasts
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// - Antwortet mit leerem UDP-Paket direkt an den Absender
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// - Client kann aus der Quell-IP der Antwort die Server-IP ermitteln
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public class DiscoveryServer implements Runnable {
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private static final int BUFSIZE = 512;
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DatagramPacket packetInDiscover = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
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private final int port;
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public DiscoveryServer(int port) {
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@ -18,8 +19,9 @@ public class DiscoveryServer implements Runnable {
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@Override
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public void run() {
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System.out.println("Discovery running on " + port);
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try (DatagramSocket discoverySocket = new DatagramSocket(port)) {
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discoverySocket.setReuseAddress(true);
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// discoverySocket.setReuseAddress(true);
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discoverySocket.setBroadcast(true);
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while (true) {
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@ -1,17 +1,11 @@
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package vs;
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// Einstiegspunkt der Anwendung:
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// - Startet zwei Threads: Syslog-UDP-Server (Port 514) und Discovery-Server (Port 8888)
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// - Erfüllt die Vorgaben: UDP-only, keine TLS, zwei Sockets, Konsolen-Ausgabe
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public class Main {
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private static final int SYSLOG_PORT = 514; // Standard-Syslog-Port (UDP)
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private static final int DISCOVERY_PORT = 8888; // Port für Auto-Discovery
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private static final int SYSLOG_PORT = 514;
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private static final int DISCOVERY_PORT = 8888;
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public static void main(String[] args) {
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// System.out.println("Syslog server is running on UDP/514 and discovery on UDP/8888...");
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// Thread 1: Empfängt Syslog-Nachrichten und druckt Sender-IP + Nachricht
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new Thread(new SyslogUdpServer(SYSLOG_PORT), "syslog").start();
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// Thread 2: Beantwortet Broadcast-Anfragen und verrät so die Server-IP
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new Thread(new DiscoveryServer(DISCOVERY_PORT), "discovery").start();
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new Thread(new SyslogUdpServer(SYSLOG_PORT), "syslog").start();
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}
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}
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@ -8,7 +8,7 @@ import java.util.concurrent.Executors;
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public class Server {
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private static final int BUFFSIZE = 512; //? Maybe andere Größe
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private static final int BUFFSIZE = 512;
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private static final ExecutorService executor = Executors.newFixedThreadPool(2);
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public interface PacketHandler {
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@ -47,7 +47,14 @@ public class Server {
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static class SyslogHandler implements PacketHandler {
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@Override
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public void handlePacket(DatagramSocket socket, DatagramPacket packetIn, String serviceName) {
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final int MAX_LENGTH = 2048;
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if (packetIn.getLength() > MAX_LENGTH){
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return;
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}
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String receivedSyslog = new String(packetIn.getData(), 0, packetIn.getLength());
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System.out.println(receivedSyslog);
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}
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}
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@ -57,10 +64,24 @@ public class Server {
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DatagramPacket packetOut = new DatagramPacket(new byte[BUFFSIZE], BUFFSIZE);
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packetOut.setSocketAddress(packetIn.getSocketAddress());
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packetOut.setData(new byte[0]);
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packetOut.setLength(0);
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System.out.println("Found client, responding");
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String receivedDataString = new String(packetIn.getData(), 0, packetIn.getLength());
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// System.out.println("Discorvery Packet: " + receivedDataString);
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byte[] repsonseMessage;
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if (receivedDataString.equals("DISCOVER")) {
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repsonseMessage = "OFFER".getBytes();
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}
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else if (receivedDataString.equals("REQUEST")) {
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repsonseMessage = "ACKNOWLEDGE".getBytes();
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// System.out.println("Acknowledged client: " + packetIn.getSocketAddress());
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}
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else {
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repsonseMessage = "ERROR".getBytes();
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}
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packetOut.setData(repsonseMessage);
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packetOut.setLength(repsonseMessage.length);
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socket.send(packetOut);
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}
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@ -4,13 +4,9 @@ import java.net.DatagramPacket;
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import java.net.DatagramSocket;
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import java.net.InetAddress;
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// UDP-Syslog-Empfänger:
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// - Hört auf Port 514 (UDP), kein TLS
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// - Prüft maximale Nachrichtenlänge (hier 1024 Bytes, RFC 5426 Empfehlung)
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// - Gibt pro Nachricht die Absender-IP:Port und den Text auf der Konsole aus
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public class SyslogUdpServer implements Runnable {
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private final int port;
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// Maximale Länge (vereinfachte Vorgabe; UDP-Empfänger sollten ~1024 Bytes unterstützen)
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private static final int MAX_MESSAGE_LENGTH = 1024;
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public SyslogUdpServer(int port) {
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@ -19,20 +15,18 @@ public class SyslogUdpServer implements Runnable {
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@Override
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public void run() {
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System.out.println("Syslog running on " + port);
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// Socket öffnen und auf allen Interfaces an Port 514 lauschen
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System.out.println("Syslog running on " + port + "\n");
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try (DatagramSocket syslogSocket = new DatagramSocket(port)) {
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syslogSocket.setReuseAddress(true); // erlaubt schnelles Neu-Starten
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byte[] buffer = new byte[MAX_MESSAGE_LENGTH + 1]; // +1 als einfache Oversize-Erkennung
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syslogSocket.setReuseAddress(true);
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byte[] buffer = new byte[MAX_MESSAGE_LENGTH + 1];
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while (true) {
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DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
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syslogSocket.receive(packet); // UDP-Paket empfangen
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System.out.println("SYSLOG from " + packet.getSocketAddress());
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syslogSocket.receive(packet);
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int len = packet.getLength();
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InetAddress clientAddress = packet.getAddress();
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// Zu lange Nachrichten verwerfen (Aufgabenforderung: Länge prüfen)
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if (len > MAX_MESSAGE_LENGTH) {
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System.err.println("Dropped oversized UDP syslog (" + len + " > " + MAX_MESSAGE_LENGTH
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+ ") from " + clientAddress.getHostAddress() + ":" + packet.getPort());
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