SMB_HDRLEN
KASSERT(mb->m_len >= SMB_HDRLEN, ("forgot to m_pullup"));
m = m_pullup(m, SMB_HDRLEN);
blksz = SSTOVC(ssp)->vc_txmax - SMB_HDRLEN - 16;
blksz = SSTOVC(ssp)->vc_txmax - SMB_HDRLEN - 16;
maxent = min(ctx->f_left, (vcp->vc_txmax - SMB_HDRLEN - 3) / SMB_DENTRYLEN);