SBS_RCVATMARK
*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
if (sb_state & SBS_RCVATMARK) {
so->so_rcv.sb_state &= ~SBS_RCVATMARK;
so->so_rcv.sb_state |= SBS_RCVATMARK;
KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
(so->so_rcv.sb_state & SBS_RCVATMARK))
so->so_rcv.sb_state |= SBS_RCVATMARK;
(so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
(so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||