BPF_D_OUT
case BPF_D_OUT:
(dir == BPF_D_OUT && ifp == rcvif));
(dir == BPF_D_OUT && ifp == rcvif));
(dir == BPF_D_OUT && m_rcvif(m) != NULL));
((bd->bd_direction == BPF_D_OUT) ? 'o' : 's');
(bd->bd_direction == BPF_D_OUT) ? "output" : "bidirectional");