Make routes maintain all three components of a metric.

route.c

@@ -259,7 +259,8 @@ change_route_metric(struct route *route, unsigned cost, unsigned add)
         }
     }
 
-    route->metric = newmetric;
+    route->cost = cost;
+    route->add_metric = add;
     local_notify_route(route, LOCAL_CHANGE);
 }
 
@@ -478,8 +479,9 @@ update_route(const unsigned char *a, const unsigned char *p, unsigned char plen,
         route = &routes[numroutes];
         route->src = src;
         route->refmetric = refmetric;
+        route->cost = neighbour_cost(neigh);
+        route->add_metric = add_metric;
         route->seqno = seqno;
-        route->metric = metric;
         route->neigh = neigh;
         memcpy(route->nexthop, nexthop, 16);
         route->time = now.tv_sec;

route.h

@@ -22,8 +22,9 @@ THE SOFTWARE.
 
 struct route {
     struct source *src;
-    unsigned short metric;
     unsigned short refmetric;
+    unsigned short cost;
+    unsigned short add_metric;
     unsigned short seqno;
     struct neighbour *neigh;
     unsigned char nexthop[16];
@@ -35,7 +36,8 @@ struct route {
 static inline int
 route_metric(const struct route *route)
 {
-    return route->metric;
+    int m = route->refmetric + route->cost + route->add_metric;
+    return MIN(m, INFINITY);
 }
 
 extern struct route *routes;