Exemplo n.º 1
0
func (tap *Wiretap) capture(handle *pcap.Handle, channel chan gopacket.Packet) {
	defer handle.Close()

	src := gopacket.NewPacketSource(handle, handle.LinkType())
	src.DecodeOptions = gopacket.NoCopy

	for {
		packet, err := src.NextPacket()
		if err == io.EOF {
			return
		} else if err == nil {
			channel <- packet
		}
	}
}
Exemplo n.º 2
0
func tryCapture(iface net.Interface) error {
	if iface.Name[:2] == "lo" {
		return fmt.Errorf("skipping loopback")
	}
	var h *pcap.Handle
	var err error
	switch *mode {
	case "basic":
		h, err = pcap.OpenLive(iface.Name, 65536, false, time.Second*3)
		if err != nil {
			return fmt.Errorf("openlive: %v", err)
		}
		defer h.Close()
	case "filtered":
		h, err = pcap.OpenLive(iface.Name, 65536, false, time.Second*3)
		if err != nil {
			return fmt.Errorf("openlive: %v", err)
		}
		defer h.Close()
		if err := h.SetBPFFilter("port 80 or port 443"); err != nil {
			return fmt.Errorf("setbpf: %v", err)
		}
	case "timestamp":
		u, err := pcap.NewInactiveHandle(iface.Name)
		if err != nil {
			return err
		}
		defer u.CleanUp()
		if err = u.SetSnapLen(65536); err != nil {
			return err
		} else if err = u.SetPromisc(false); err != nil {
			return err
		} else if err = u.SetTimeout(time.Second * 3); err != nil {
			return err
		}
		sources := u.SupportedTimestamps()
		if len(sources) == 0 {
			return fmt.Errorf("no supported timestamp sources")
		} else if err := u.SetTimestampSource(sources[0]); err != nil {
			return fmt.Errorf("settimestampsource(%v): %v", sources[0], err)
		} else if h, err = u.Activate(); err != nil {
			return fmt.Errorf("could not activate: %v", err)
		}
		defer h.Close()
	default:
		panic("Invalid --mode: " + *mode)
	}
	go generatePackets()
	h.ReadPacketData() // Do one dummy read to clear any timeouts.
	data, ci, err := h.ReadPacketData()
	if err != nil {
		return fmt.Errorf("readpacketdata: %v", err)
	}
	log.Printf("Read packet, %v bytes, CI: %+v", len(data), ci)
	return nil
}