Example #1
0
// OpenLive opens a device and returns a *Handle.
// It takes as arguments the name of the device ("eth0"), the maximum size to
// read for each packet (snaplen), whether to put the interface in promiscuous
// mode, and a timeout.
func OpenLive(device string, snaplen int32, promisc bool, timeout time.Duration) (handle *Handle, _ error) {
	var buf *C.char
	buf = (*C.char)(C.calloc(errorBufferSize, 1))
	defer C.free(unsafe.Pointer(buf))
	var pro C.int
	if promisc {
		pro = 1
	}

	dev := C.CString(device)
	defer C.free(unsafe.Pointer(dev))

	// This copies a bunch of the pcap_open_live implementation from pcap.c:
	cptr := C.pcap_create(dev, buf)
	if cptr == nil {
		return nil, errors.New(C.GoString(buf))
	}
	var status C.int
	if status = C.pcap_set_snaplen(cptr, C.int(snaplen)); status < 0 {
		goto fail
	} else if status = C.pcap_set_promisc(cptr, pro); status < 0 {
		goto fail
	} else if status = C.pcap_set_timeout(cptr, C.int(timeout/time.Millisecond)); status < 0 {
		goto fail
	}
	return newHandle(cptr), nil
fail:
	C.pcap_close(cptr)
	return nil, statusError(status)
}
Example #2
0
func (h *Handle) SetMTU(mtu int) error {
	err := C.pcap_set_snaplen(h.pcap, C.int(mtu))
	if err < 0 {
		return fmt.Errorf("Handle already active")
	}

	return nil
}
Example #3
0
// SetSnaplen should only be called on a Pcap that was obtained through Create.
func (p *Pcap) SetSnaplen(snaplen int32) error {
	res := int32(C.pcap_set_snaplen(p.cptr, C.int(snaplen)))
	if res < 0 {
		return fmt.Errorf("%s(errnum=%d)", Statustostr(res), res)
	}
	p.Snaplen = snaplen
	return nil
}
Example #4
0
func main() {
	var errbuf = (*C.char)(C.malloc(C.PCAP_ERRBUF_SIZE))
	defer C.free(unsafe.Pointer(errbuf))
	var source = C.CString("any")
	defer C.free(unsafe.Pointer(source))

	pcap_handle := C.pcap_create(source, errbuf)
	if pcap_handle == nil {
		panic("pcap_handle")
	}
	C.pcap_set_buffer_size(pcap_handle, 2*1024*1024)
	C.pcap_set_promisc(pcap_handle, 1)
	C.pcap_set_snaplen(pcap_handle, 512) // more than enough to recognize a WOL packet
	C.pcap_setdirection(pcap_handle, C.PCAP_D_IN)
	if C.pcap_activate(pcap_handle) != 0 {
		panic(C.GoString(C.pcap_geterr(pcap_handle)))
	}

	var bpf_program C.struct_bpf_program
	if C.pcap_compile(pcap_handle, &bpf_program, pcap_filter, 0, 0) != 0 {
		panic(C.GoString(C.pcap_geterr(pcap_handle)))
	}
	if C.pcap_setfilter(pcap_handle, &bpf_program) != 0 {
		panic(C.GoString(C.pcap_geterr(pcap_handle)))
	}

	for {
		var pkt_header *C.struct_pcap_pkthdr
		var pkt_data *C.u_char
		if C.pcap_next_ex(pcap_handle, &pkt_header, &pkt_data) < 0 {
			panic(C.GoString(C.pcap_geterr(pcap_handle)))
		}
		if pkt_data == nil {
			continue
		}
		data := make([]byte, pkt_header.caplen)
		copy(data, (*(*[10000000]byte)(unsafe.Pointer(pkt_data)))[0:])
		from_mac, to_mac := checkwol(data)
		if from_mac != "" {
			fmt.Printf("%v: %v sends WOL to %v\n", time.Now(), from_mac, to_mac)
		}
	}

}
Example #5
0
// SetSnapLen sets the snap length (max bytes per packet to capture).
func (p *InactiveHandle) SetSnapLen(snaplen int) error {
	if status := C.pcap_set_snaplen(p.cptr, C.int(snaplen)); status < 0 {
		return statusError(status)
	}
	return nil
}
Example #6
0
func (p *Pcap) SetSnapLen(s int32) error {
	if C.pcap_set_snaplen(p.cptr, C.int(s)) != 0 {
		return p.Geterror()
	}
	return nil
}