taglinefilesource code
rt_metric37include/linux/route.hshort    rt_metric;  /* +1 for binary compatibility!  */
rt_metric1572net/ipv4/route.cmetric = r->rt_metric > 0 ? r->rt_metric - 1 : 0;
rt_metric1678net/ipv4/route.c(__u32)gtw->sin_addr.s_addr, r->rt_flags, r->rt_metric - 1);