Example #1
0
// readARP watches a handle for incoming ARP responses we might care about, and prints them.
//
// readARP loops until 'stop' is closed.
func readARP(handle *pcap.Handle, iface *net.Interface, stop chan struct{}) {
	src := gopacket.NewPacketSource(handle, layers.LayerTypeEthernet)
	in := src.Packets()
	for {
		var packet gopacket.Packet
		select {
		case <-stop:
			return
		case packet = <-in:
			arpLayer := packet.Layer(layers.LayerTypeARP)
			if arpLayer == nil {
				continue
			}
			arp := arpLayer.(*layers.ARP)
			if arp.Operation != layers.ARPReply || bytes.Equal([]byte(iface.HardwareAddr), arp.SourceHwAddress) {
				// This is a packet I sent.
				continue
			}
			// Note:  we might get some packets here that aren't responses to ones we've sent,
			// if for example someone else sends US an ARP request.  Doesn't much matter, though...
			// all information is good information :)
			log.Printf("IP %v is at %v", net.IP(arp.SourceProtAddress), net.HardwareAddr(arp.SourceHwAddress))
		}
	}
}
Example #2
0
func handlePacket(p gopacket.Packet) {
	ap := AP{}
	// extract beacon
	// extract Ssid
	for _, l := range p.Layers() {
		switch l.LayerType() {
		case layers.LayerTypeDot11MgmtBeacon:
			beacon, ok := p.Layer(layers.LayerTypeDot11MgmtBeacon).(*layers.Dot11MgmtBeacon)
			if !ok {
				log.Println("Could not marshal layer thing")
				continue
			}
			pack := gopacket.NewPacket(beacon.LayerContents(), layers.LayerTypeDot11MgmtBeacon, gopacket.Default)
			for _, subpack := range pack.Layers() {
				info, ok := subpack.(*layers.Dot11InformationElement)
				if !ok {
					continue
				}
				if info.ID == layers.Dot11InformationElementIDSSID {
					ap.Ssid = fmt.Sprintf("%s", info.Info)
					break
				}
			}
		case layers.LayerTypeDot11:
			base, ok := p.Layer(layers.LayerTypeDot11).(*layers.Dot11)
			if !ok {
				continue
			}
			ap.Bssid = base.Address2
			continue
		case layers.LayerTypeRadioTap:
			radio, ok := p.Layer(layers.LayerTypeRadioTap).(*layers.RadioTap)
			if !ok {
				continue
			}
			ap.Channel = radio.ChannelFrequency
			continue

		}
	}
	APList[ap.Ssid] = ap
}
//Returns both the source & destination IP.
func getSrcDstIP(packet gopacket.Packet) (net.IP, net.IP) {
	ipLayer := packet.Layer(layers.LayerTypeIPv4)
	// Get IP data from this layer
	ip, _ := ipLayer.(*layers.IPv4)
	return ip.SrcIP, ip.DstIP
}