Man page 9 : xdr_encode_opaque_fixed

xdr_encode_opaque_fixed - Encode fixed length opaque data

__be32 * xdr_encode_opaque_fixed(__be32 *  p , const void *  ptr , unsigned int  nbytes );

p
    pointer to current position in XDR buffer.

ptr
    pointer to data to encode (or NULL)

nbytes
    size of data.

Copy the array of data of length nbytes at ptr to the XDR buffer at position p, then align to the next 32-bit boundary by padding with zero bytes (see RFC1832).

if ptr is NULL, only the padding is performed.

Returns the updated current XDR buffer position