RTM_F_PREFIX
filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
if (filter.flags & RTM_F_PREFIX)
if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
if (rtm->rtm_flags & RTM_F_PREFIX)
arg.filter.flags = RTM_F_PREFIX;
if ((filter->flags & RTM_F_PREFIX) &&