//Opens a pcap handle
func OpenActiveDevice(dev string, snaplen uint32, promisc bool, timeout_ms uint32, filter string) (*Pcap, error) {
var cbuf *C.char
cbuf = (*C.char)(C.calloc(ERRBUF_SIZE, 1))
handle := new(Pcap)
var cpromisc int32 = 0
if promisc {
cpromisc = 1
}
cdev := C.CString(dev)
defer C.free(unsafe.Pointer(cdev))
handle.cptr = C.pcap_open_live(cdev, C.int(snaplen), C.int(cpromisc), C.int(timeout_ms), cbuf)
if handle.cptr == nil {
return nil, errors.New(C.GoString(cbuf))
}
x := C.pcap_datalink(handle.cptr)
handle.linkLayer = uint16(x)
C.free(unsafe.Pointer(cbuf))
if filter != "" {
ret := int32(C.pcap_set_filter(handle.cptr, cdev, C.CString(filter), cbuf, ERRBUF_SIZE-1))
if ret != 0 {
C.free(unsafe.Pointer(handle.cptr))
return nil, errors.New(C.GoString(cbuf))
}
}
return handle, nil
}
func (p *Pcap) Datalink() int {
return int(C.pcap_datalink(p.cptr))
}
// LinkType returns pcap_datalink, as a layers.LinkType.
func (p *Handle) LinkType() layers.LinkType {
return layers.LinkType(C.pcap_datalink(p.cptr))
}
// Return the link type of the capture handle (that is, the type of packets that
// come out of the packet source).
func (h *Handle) LinkType() packet.Type {
return packet.LinkType(uint32(C.pcap_datalink(h.pcap)))
}