func (d *afpacket) Read(to *ethernet.Frame) (err error) {
to.Resize(d.ifce.MTU)
for {
*to = (*to)[:cap(*to)]
var n int
n, _, err = unix.Recvfrom(d.fd, []byte(*to), 0)
if err != nil {
return
}
*to = (*to)[:n]
if !equalMAC(to.Source(), d.ifce.HardwareAddr) && (d.filter == nil || d.filter(*to)) {
return
}
}
}
func (d *bpfDev) Read(to *ethernet.Frame) (err error) {
to.Resize(d.ifce.MTU)
for {
for d.p < d.n {
hdr := (*bpfHdr)(unsafe.Pointer(&d.readBuf[d.p]))
frameStart := d.p + int(hdr.hdrlen)
n := int(hdr.caplen)
*to = (*to)[:n]
copy(*to, d.readBuf[frameStart:frameStart+n])
d.p += bpfWordalign(int(hdr.hdrlen) + int(hdr.caplen))
if !equalMAC(to.Source(), d.ifce.HardwareAddr) && (d.filter == nil || d.filter(*to)) {
return
}
}
d.n, err = d.fd.Read(d.readBuf)
if err != nil {
return
}
d.p = 0
}
}