rt_metrics
rtm.rtm_rmx = rt_metrics;
#define caseof(x, y, z) case x: valp = &rt_metrics.z; flag = y; break
rt_metrics.rmx_locks |= flag;
static struct rt_metrics rt_metrics;
struct rt_metrics rt_rmx; /* metrics used by rx'ing protocols */
struct rt_metrics rtm_rmx; /* metrics themselves */
static void rt_setmetrics (u_long, struct rt_metrics *,
struct rt_metrics *);
rt_setmetrics(u_long which, struct rt_metrics *in, struct rt_metrics *out)