4 files changed, 158 insertions, 0 deletions
diff --git a/vnfs/vLB/DNSClient/src/main/.DS_Store b/vnfs/vLB/DNSClient/src/main/.DS_Store
new file mode 100644
index 00000000..9206bc71
--- /dev/null
+++ b/vnfs/vLB/DNSClient/src/main/.DS_Store
diff --git a/vnfs/vLB/DNSClient/src/main/java/.DS_Store b/vnfs/vLB/DNSClient/src/main/java/.DS_Store
new file mode 100644
index 00000000..05c35472
--- /dev/null
+++ b/vnfs/vLB/DNSClient/src/main/java/.DS_Store
diff --git a/vnfs/vLB/DNSClient/src/main/java/DNSServer.java b/vnfs/vLB/DNSClient/src/main/java/DNSServer.java
new file mode 100644
index 00000000..483819f3
--- /dev/null
+++ b/vnfs/vLB/DNSClient/src/main/java/DNSServer.java
@@ -0,0 +1,85 @@
+
+/*************************************************************************//**
+ *
+ * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ ****************************************************************************/
+
+package main.java;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+
+/*
+ * Client-side Failure Detector (FD) implementation.
+ * @param server_addr: IP address of the remote server
+ * @param port: the port that the FD service listens for incoming UDP packets
+ * @param timeout: how often the FD checks the status of client processes
+ * @param debug: debug mode on/off
+ */
+
+public class DNSServer {
+
+	public static void main(String[] args) throws IOException {
+		if(args.length != 5) {
+			System.out.println("Missing input parameters");
+			System.out.println("Usage:");
+			System.out.print("\t- java FDClient [process ID] [server IP address] [server port] [timeout (sec)] [debug]\n");
+			System.exit(0);
+		}
+		// IP address and port of the remote server
+		String PID = args[0];
+		String SERVER_ADDR = args[1];
+		int PORT = Integer.parseInt(args[2]);
+		long TIMEOUT = Long.parseLong(args[3]) * 1000; // convert the FD timeout to milliseconds
+		int debug = Integer.parseInt(args[4]);
+		boolean DEBUG;
+		if(debug <= 0)
+			DEBUG = false;
+		else
+			DEBUG = true;
+		
+		// Run FD client
+		new FDClient(PID, SERVER_ADDR, PORT, TIMEOUT, DEBUG);
+		
+		// Listen for reply messages
+		@SuppressWarnings("resource")
+		DatagramSocket sock = new DatagramSocket(PORT);
+		byte[] buffer = new byte[256];
+		boolean gre_tunnel_enabled = false;
+		
+		while(true) {
+			DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
+            sock.receive(packet);
+            String[] content = new String(packet.getData()).trim().split(":"); // Remove leading and trailing spaces
+            String msg_type = content[0];
+            String ip = content[1];
+            // Process only PING UDP packets
+            if(msg_type.equals("PONG")) {
+				if(DEBUG) System.out.println("Reply message received from process " + ip);
+				if(!gre_tunnel_enabled) {
+					// Set GRE tunnel towards load balancer
+					String script = new String("bash /opt/FDclient/set_gre_tunnel.sh " + ip);
+		            Runtime.getRuntime().exec(script);
+					if(DEBUG) System.out.println("GRE tunnel towards load balancer " + ip + " done");
+					gre_tunnel_enabled = true;
+				}
+            }
+            else {
+            	if(DEBUG) System.out.println("The received message is not a PONG. Received content: " + content);
+            }
+		}
+	}
+}
diff --git a/vnfs/vLB/DNSClient/src/main/java/FDClient.java b/vnfs/vLB/DNSClient/src/main/java/FDClient.java
new file mode 100644
index 00000000..8665937a
--- /dev/null
+++ b/vnfs/vLB/DNSClient/src/main/java/FDClient.java
@@ -0,0 +1,73 @@
+
+/*************************************************************************//**
+ *
+ * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ ****************************************************************************/
+
+package main.java;
+
+import java.io.*;
+import java.net.*;
+
+/*
+ * Client-side Failure Detector (FD) implementation.
+ * @param server_addr: IP address of the remote server
+ * @param port: the port that the FD service listens for incoming UDP packets
+ * @param timeout: how often the FD checks the status of client processes
+ * @param debug: debug mode on/off
+ */
+
+public class FDClient implements Runnable {
+	private String PID;
+	private String SERVER_ADDR;
+	private int PORT;
+	private long TIMEOUT;
+	private boolean DEBUG;
+	
+	public FDClient(String pid, String server_addr, int port, long timeout, boolean debug) throws IOException {
+		PID = pid;
+		SERVER_ADDR = server_addr;
+		PORT = port;
+		TIMEOUT = timeout;
+		DEBUG = debug;
+		(new Thread(this)).start();
+	}
+
+	@SuppressWarnings("resource")
+	@Override
+	public void run() {
+		// Define a DatagramSocket object to send packets to the server
+		try {
+			DatagramSocket sock = new DatagramSocket();
+			InetAddress IPAddress = InetAddress.getByName(SERVER_ADDR);
+
+			// Allocate buffer for the PING message
+			String content = "PING:" + PID;
+			byte[] buffer = content.getBytes();
+		
+			// Sent a PING message every TIMEOUT milliseconds
+			while(true) {
+				DatagramPacket packet = new DatagramPacket(buffer, buffer.length, IPAddress, PORT);
+				sock.send(packet);
+
+				if(DEBUG) System.out.println("Sent PING message to server " + SERVER_ADDR + ":" + PORT);
+				try {
+					Thread.sleep(TIMEOUT);
+				}
+				catch(InterruptedException e) {}
+			} 
+		} catch(IOException e) {}
+	}
+}