NUD_DELAY
#define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
#define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
if (!(READ_ONCE(neigh->nud_state) & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE)))
{ NUD_DELAY, "delay" }, \
WRITE_ONCE(neigh->nud_state, NUD_DELAY);
} else if (state & NUD_DELAY) {
if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
WRITE_ONCE(neigh->nud_state, NUD_DELAY);