Call back into babel when a route changes.

babel.c

@@ -79,6 +79,7 @@ struct network *add_network(char *ifname, int ifindex, int bufsize,
                             int wired, unsigned int cost, int hello_interval);
 void expire_routes(void);
 
+static int kernel_routes_changed(void *closure);
 static void init_signals(void);
 static void dump_tables(FILE *out);
 
@@ -407,7 +408,7 @@ main(int argc, char **argv)
             break;
 
         if(kernel_socket >= 0 && FD_ISSET(kernel_socket, &readfds)) {
-            kernel_callback();
+            kernel_callback(kernel_routes_changed, NULL);
         }
 
         if(FD_ISSET(protocol_socket, &readfds)) {
@@ -620,6 +621,12 @@ dump_tables(FILE *out)
     fflush(out);
 }
 
+static int
+kernel_routes_changed(void *closure)
+{
+    return 0;
+}
+
 struct network *
 add_network(char *ifname, int ifindex, int mtu,
             int wired, unsigned int cost, int hello_interval)

kernel.c

@@ -790,10 +790,16 @@ kernel_routes(int maxplen, struct kernel_route *routes, int maxroutes)
 }
 
 int
-kernel_callback()
+kernel_callback(int (*fn)(void*), void *closure)
 {
+    int rc;
+
     if(nl_listen.sock < 0)
         return -1;
 
-    return netlink_listen(monitor_kernel_route, NULL);
+    rc = netlink_listen(monitor_kernel_route, NULL);
+    if(rc)
+        return fn(closure);
+
+    return 0;
 }

kernel.h

@@ -42,4 +42,4 @@ int kernel_route(int operation, const unsigned char *dest, unsigned short plen,
                  const unsigned char *gate, int ifindex,
                  unsigned int metric, unsigned int newmetric);
 int kernel_routes(int maxplen, struct kernel_route *routes, int maxroutes);
-int kernel_callback(void);
+int kernel_callback(int (*fn)(void*), void *closure);