// writeARP writes an ARP request for each address on our local network to the
// pcap handle.
func writeARP(handle *pcap.Handle, iface *net.Interface, addr *net.IPNet) error {
// Set up all the layers' fields we can.
eth := layers.Ethernet{
SrcMAC: iface.HardwareAddr,
DstMAC: net.HardwareAddr{0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
EthernetType: layers.EthernetTypeARP,
}
arp := layers.ARP{
AddrType: layers.LinkTypeEthernet,
Protocol: layers.EthernetTypeIPv4,
HwAddressSize: 6,
ProtAddressSize: 4,
Operation: layers.ARPRequest,
SourceHwAddress: []byte(iface.HardwareAddr),
SourceProtAddress: []byte(addr.IP),
DstHwAddress: []byte{0, 0, 0, 0, 0, 0},
}
// Set up buffer and options for serialization.
buf := gopacket.NewSerializeBuffer()
opts := gopacket.SerializeOptions{
FixLengths: true,
ComputeChecksums: true,
}
// Send one packet for every address.
for _, ip := range ips(addr) {
arp.DstProtAddress = []byte(ip)
gopacket.SerializeLayers(buf, opts, ð, &arp)
if err := handle.WritePacketData(buf.Bytes()); err != nil {
return err
}
}
return nil
}
func TestInformationElement(t *testing.T) {
bin := []byte{
0, 0,
0, 2, 1, 3,
221, 5, 1, 2, 3, 4, 5,
}
pkt := gopacket.NewPacket(bin, LayerTypeDot11InformationElement, gopacket.NoCopy)
buf := gopacket.NewSerializeBuffer()
var sLayers []gopacket.SerializableLayer
for _, l := range pkt.Layers() {
sLayers = append(sLayers, l.(*Dot11InformationElement))
}
if err := gopacket.SerializeLayers(buf, gopacket.SerializeOptions{}, sLayers...); err != nil {
t.Error(err.Error())
}
if !bytes.Equal(bin, buf.Bytes()) {
t.Error("build failed")
}
}