Scatter/Gather Data Transfer Interfaces

t_sndvudata(3N): Send a data unit from one or more non-contiguous buffers
t_rcvvudata(3N): Receive a data unit into one or more non-contiguous buffers
t_sndv(3N): Send data or expedited data from one or more non-contiguous buffers on a connection
t_rcvv(3N): Receive data or expedited data sent over a connection and put the data into one or more non-contiguous buffers