qualifiers are DLT_SLIP and DLT_PPP (i.e. old-style serial encap PPP).
If an attempt to use these qualifiers is used for any other link type,
cause a BPF program compilation error.
serious race condition in sosend(). Upon closer inspection, the appropriate
flags are checked within splsoftnet() for soreceive(), so no change needed
there. Also a little KNFing in sosend().
headaches.
Now console keyboard and display are connected at autoconfiguration time,
when the last of them is found. Other keyboards / displays remain
unconnected until a new ioctl (WSDISPLAYIO_SETKEYBOARD) is called.