TF2_PLPMTU_BLACKHOLE
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;