Example #1
0
func main() {
	var device *string = flag.String("i", "", "interface")
	var snaplen *int = flag.Int("s", 65535, "snaplen")
	var hexdump *bool = flag.Bool("X", false, "hexdump")
	expr := ""

	out = bufio.NewWriter(os.Stdout)
	errout = bufio.NewWriter(os.Stderr)

	flag.Usage = func() {
		fmt.Fprintf(errout, "usage: %s [ -i interface ] [ -s snaplen ] [ -X ] [ expression ]\n", os.Args[0])
		os.Exit(1)
	}

	flag.Parse()

	if len(flag.Args()) > 0 {
		expr = flag.Arg(0)
	}

	if *device == "" {
		devs, err := pcap.Findalldevs()
		if err != "" {
			fmt.Fprintf(errout, "tcpdump: couldn't find any devices: %s\n", err)
		}
		if 0 == len(devs) {
			flag.Usage()
		}
		*device = devs[0].Name
	}

	h, err := pcap.Openlive(*device, int32(*snaplen), true, 0)
	if h == nil {
		fmt.Fprintf(errout, "tcpdump: %s\n", err)
		errout.Flush()
		return
	}

	if expr != "" {
		ferr := h.Setfilter(expr)
		if ferr != "" {
			fmt.Fprintf(out, "tcpdump: %s\n", ferr)
			out.Flush()
		}
	}

	for pkt := h.Next(); pkt != nil; pkt = h.Next() {
		Printpacket(pkt)
		if *hexdump {
			Hexdump(pkt)
		}
		out.Flush()
	}

}
Example #2
0
func show_devices() {
	ifs, err := pcap.Findalldevs()
	if len(ifs) == 0 {
		fmt.Print("Warning: no devices found.\n")
		if err != nil {
			fmt.Printf("Error: %s\n", err)
		} else {
			fmt.Print("Maybe you have not the good rights\n")
		}
	} else {
		for i, _ := range ifs {
			fmt.Printf("dev %d: %s (%s)\n", i+1, ifs[i].Name, ifs[i].Description)
		}
	}
}
Example #3
0
func main() {
	var device *string = flag.String("d", "", "device")
	var file *string = flag.String("r", "", "file")
	var expr *string = flag.String("e", "", "filter expression")

	flag.Parse()

	var h *pcap.Pcap
	var err string

	ifs, err := pcap.Findalldevs()
	if len(ifs) == 0 {
		fmt.Printf("Warning: no devices found : %s\n", err)
	} else {
		for i := 0; i < len(ifs); i++ {
			fmt.Printf("dev %d: %s (%s)\n", i+1, ifs[i].Name, ifs[i].Description)
		}
	}

	if *device != "" {
		h, err = pcap.Openlive(*device, 65535, true, 0)
		if h == nil {
			fmt.Printf("Openlive(%s) failed: %s\n", *device, err)
			return
		}
	} else if *file != "" {
		h, err = pcap.Openoffline(*file)
		if h == nil {
			fmt.Printf("Openoffline(%s) failed: %s\n", *file, err)
			return
		}
	} else {
		fmt.Printf("usage: pcaptest [-d <device> | -r <file>]\n")
		return
	}

	fmt.Printf("pcap version: %s\n", pcap.Version())

	if *expr != "" {
		fmt.Printf("Setting filter: %s\n", *expr)
		err := h.Setfilter(*expr)
		if err != "" {
			fmt.Printf("Warning: setting filter failed: %s\n", err)
		}
	}

	for pkt := h.Next(); pkt != nil; pkt = h.Next() {
		fmt.Printf("time: %d.%06d (%s) caplen: %d len: %d\nData:",
			int64(pkt.Time.Sec), int64(pkt.Time.Usec),
			time.SecondsToLocalTime(int64(pkt.Time.Sec)).String(), int64(pkt.Caplen), int64(pkt.Len))
		for i := uint32(0); i < pkt.Caplen; i++ {
			if i%32 == 0 {
				fmt.Printf("\n")
			}
			if 32 <= pkt.Data[i] && pkt.Data[i] <= 126 {
				fmt.Printf("%c", pkt.Data[i])
			} else {
				fmt.Printf(".")
			}
		}
		fmt.Printf("\n\n")
	}

}