The svc_register
function shall associate
the program identified by prognum at version
versnum
with the service dispatch procedure, dispatch.
If protocol is zero, the service is not registered with the
portmap service. If protocol is
non-zero, then a mapping of the triple [prognum,
versnum, protocol] to
xprt->xp_port is established with the local
portmap service. The
procedure dispatch has the following form: