Retract xroutes by setting their cost to infinity.

This makes sure we advertise xroutes after they are retracted.  They
will be flushed by the normal GC mechanism.

route.c

@@ -321,10 +321,8 @@ update_route(const unsigned char *d, int seqno, int refmetric,
         route->refmetric = refmetric;
         change_route_metric(route, metric);
         if(seqno_compare(oldseqno, seqno) <= 0) {
-            if(seqno_compare(oldseqno, seqno) < 0) {
-                /* Flush retracted xroutes */
-                flush_xroutes(dest, pxroutes, numpxroutes);
-            }
+            if(seqno_compare(oldseqno, seqno) < 0)
+                retract_xroutes(dest, pxroutes, numpxroutes);
             for(i = 0; i < numpxroutes; i++)
                 update_xroute(pxroutes[i].prefix,
                               pxroutes[i].plen,

xroute.c

@@ -209,24 +209,21 @@ flush_xroute(struct xroute *xroute)
 }
 
 void
-flush_xroutes(struct destination *gateway,
-              const struct xroute *except, int numexcept)
+retract_xroutes(struct destination *gateway,
+                const struct xroute *except, int numexcept)
 {
     int i, j;
 
-    i = 0;
-    while(i < numxroutes) {
-        if(xroutes[i].gateway == gateway) {
+    for(i = 0; i < numxroutes; i++) {
+        if(xroutes[i].cost < INFINITY && xroutes[i].gateway == gateway) {
             for(j = 0; j < numexcept; j++) {
                 if(memcmp(xroutes[i].prefix, except[j].prefix, 16) == 0 &&
                    xroutes[i].plen == except[j].plen)
                     goto skip;
             }
-            flush_xroute(&xroutes[i]);
-            continue;
+            update_xroute_metric(&xroutes[i], INFINITY);
         }
-    skip:
-        i++;
+    skip: ;
     }
 }
 

xroute.h

@@ -44,8 +44,8 @@ void install_xroute(struct xroute *xroute);
 void uninstall_xroute(struct xroute *xroute);
 void consider_xroute(struct xroute *xroute);
 void flush_xroute(struct xroute *xroute);
-void flush_xroutes(struct destination *gateway,
-                   const struct xroute *except, int numexcept);
+void retract_xroutes(struct destination *gateway,
+                     const struct xroute *except, int numexcept);
 struct xroute * update_xroute(const unsigned char *prefix, unsigned short plen,
                               struct destination *gateway, int cost);
 void update_xroute_metric(struct xroute *xroute, int cost);