RPC_CALLHDRSIZE
(RPC_CALLHDRSIZE + 2 * (2 + UNX_CALLSLACK))
(RPC_CALLHDRSIZE + 2*(2+RPC_MAX_AUTH_SIZE/4))
req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);