func main() {
expr := ""
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "usage: %s [ -i interface ] [ -s snaplen ] [ -X ] [ -w file ] [ -h show usage] [ expression ] \n", os.Args[0])
os.Exit(1)
}
flag.Parse()
if len(flag.Args()) > 0 {
expr = flag.Arg(0)
}
if *help {
flag.Usage()
}
if *device == "" {
devs, err := pcap.FindAllDevs()
if err != "" {
fmt.Fprintln(os.Stderr, "tcpdump: couldn't find any devices:", err)
}
if 0 == len(devs) {
flag.Usage()
}
*device = devs[0].Name
}
h, err := pcap.OpenLive(*device, int32(*snaplen), true, 500)
if h == nil {
fmt.Fprintf(os.Stderr, "tcpdump:", err)
return
}
defer h.Close()
if expr != "" {
fmt.Println("tcpdump: setting filter to", expr)
ferr := h.SetFilter(expr)
if ferr != nil {
fmt.Println("tcpdump:", ferr)
}
}
if *ofile != "" {
dumper, oerr := h.DumpOpen(ofile)
addHandler(h, dumper)
if oerr != nil {
fmt.Fprintln(os.Stderr, "tcpdump: couldn't write to file:", oerr)
}
_, lerr := h.PcapLoop(0, dumper)
if lerr != nil {
fmt.Fprintln(os.Stderr, "tcpdump: loop error:", lerr, h.Geterror())
}
defer h.PcapDumpClose(dumper)
return
}
for pkt, r := h.NextEx(); r >= 0; pkt, r = h.NextEx() {
if r == 0 {
// timeout, continue
continue
}
pkt.Decode()
fmt.Println(pkt)
if *hexdump {
Hexdump(pkt)
}
}
fmt.Fprintln(os.Stderr, "tcpdump:", h.Geterror())
}
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.Unix(int64(pkt.Time.Sec), 0).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")
}
}