System.exit(0);
}
//initialize Jpcap
NetworkInterface device=JpcapCaptor.getDeviceList()[Integer.parseInt(args[0])];
JpcapCaptor captor=JpcapCaptor.openDevice(device,2000,false,5000);
InetAddress thisIP=null;
for(NetworkInterfaceAddress addr:device.addresses)
if(addr.address instanceof Inet4Address){
thisIP=addr.address;
break;
}
//obtain MAC address of the default gateway
InetAddress pingAddr=InetAddress.getByName("www.microsoft.com");
captor.setFilter("tcp and dst host "+pingAddr.getHostAddress(),true);
byte[] gwmac=null;
while(true){
new URL("http://www.microsoft.com").openStream().close();
Packet ping=captor.getPacket();
if(ping==null){
System.out.println("cannot obtain MAC address of default gateway.");
System.exit(-1);
}else if(Arrays.equals(((EthernetPacket)ping.datalink).dst_mac,device.mac_address))
continue;
gwmac=((EthernetPacket)ping.datalink).dst_mac;
break;
}
//create ICMP packet
ICMPPacket icmp=new ICMPPacket();
icmp.type=ICMPPacket.ICMP_ECHO;
icmp.seq=100;
icmp.id=0;
icmp.setIPv4Parameter(0,false,false,false,0,false,false,false,0,0,0,IPPacket.IPPROTO_ICMP,
thisIP,InetAddress.getByName(args[1]));
icmp.data="data".getBytes();
EthernetPacket ether=new EthernetPacket();
ether.frametype=EthernetPacket.ETHERTYPE_IP;
ether.src_mac=device.mac_address;
ether.dst_mac=gwmac;
icmp.datalink=ether;
captor.setFilter("icmp and dst host "+thisIP.getHostAddress(),true);
JpcapSender sender=captor.getJpcapSenderInstance();
//JpcapSender sender=JpcapSender.openDevice(device);
sender.sendPacket(icmp);
while(true){
ICMPPacket p=(ICMPPacket) captor.getPacket();
//System.out.println("received "+p);
if(p==null){
System.out.println("Timeout");
}else if(p.type==ICMPPacket.ICMP_TIMXCEED){
p.src_ip.getHostName();