In the tap-win32 driver a check in AdapterTransmit(..) prevents
multicast packets from ever reaching user space.
More specifically it is the following check:
// Only accept directed packets,
// not broadcasts.
if (memcmp (e, &l_Adapter->m_TapToUser, ETHERNET_HEADER_SIZE))
goto no_queue;
Judging from the comment the check is put in to discard broadcast
traffic, but it will also trigger on multicast traffic.
Would it be reasonable to change this to do a more direct check for
broadcast traffic or add an exception when multicast traffic is
detected?
