java: add new test that perform external TCP communication

requires starting qemu with tap networking, first install libvirt
then launch the run script as root with the -n option.

Example:

$ sudo ./scripts/run.py -d -n

in osv you'll have to configure networking as follows:

$ ifconfig virtio-net0 192.168.122.100 netmask 255.255.255.0 up
$ route add default gw 192.168.122.1

java/cli/com/cloudius/cli/tests/TCPExternalCommunication.java

+package com.cloudius.cli.tests;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.net.InetAddress;
+import java.net.Socket;
+
+public class TCPExternalCommunication implements Test {
+
+    @Override
+    public boolean run() {
+        try {
+            System.out.println("[~] connecting to 173.194.70.113...");
+            Socket s = new Socket(InetAddress.getByName("173.194.70.113"), 80);
+            s.setSoTimeout(2000);
+            
+            BufferedReader in = new BufferedReader( 
+                    new InputStreamReader(s.getInputStream()));
+            BufferedWriter out = new BufferedWriter(
+                    new OutputStreamWriter(s.getOutputStream()));
+            
+            System.out.println("[~] Client: writing message...");
+            out.write("GET / HTTP/1.0\r\n\r\n");
+            out.flush();
+            
+            System.out.println("[~] Client: reading response...");
+            char[] buf = new char[512];
+            in.read(buf);
+
+            System.out.println("[~] Client: message received:");
+            System.out.println(buf);
+            
+            System.out.println("[~] Client: closing connection");
+            out.close(); 
+            in.close();
+            s.close();
+            
+            return (true);
+        } catch (Exception ex) {
+            System.out.println("[-] Exception in TCPEchoClient!");
+            System.out.println(ex.getMessage());
+            ex.printStackTrace();
+            return (false);
+        }
+    }
+    
+    
+}
\ No newline at end of file

java/cli/com/cloudius/cli/tests/TestRunner.java

@@ -65,6 +65,7 @@ public class TestRunner extends ScriptableObject {
     @JSFunction
     public void registerAllTests() {
         this.register("TCPEchoServerTest", new TCPEchoServerTest());
+        this.register("TCPExternalCommunication", new TCPExternalCommunication());
         this.registerELFTests();
     }