1 files changed, 85 insertions, 0 deletions
diff --git a/vnfs/vLB/DNSClient/src/main/java/DNSServer.java b/vnfs/vLB/DNSClient/src/main/java/DNSServer.java
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+++ 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);
+            }
+		}
+	}
+}