Rewrite token bucket.

message.c

@@ -329,17 +329,18 @@ handle_request(struct neighbour *neigh, const unsigned char *prefix,
 static int
 check_bucket(struct network *net)
 {
-    if(net->bucket > 0 && now.tv_sec > net->bucket_time) {
-        net->bucket =
-            MIN(MAX((int)net->bucket - 40 * (now.tv_sec - net->bucket_time),
-                    0),
-                400);
+    if(net->bucket <= 0) {
+        int seconds = now.tv_sec - net->bucket_time;
+        if(seconds > 0) {
+            net->bucket = MIN(BUCKET_TOKENS_MAX,
+                              seconds * BUCKET_TOKENS_PER_SEC);
         }
-
+        /* Reset bucket time unconditionally, in case clock is stepped. */
         net->bucket_time = now.tv_sec;
+    }
 
-    if(net->bucket < 400) {
-        net->bucket++;
+    if(net->bucket > 0) {
+        net->bucket--;
         return 1;
     } else {
         return 0;

message.h

@@ -22,6 +22,9 @@ THE SOFTWARE.
 
 #define MAX_BUFFERED_UPDATES 200
 
+#define BUCKET_TOKENS_MAX 200
+#define BUCKET_TOKENS_PER_SEC 40
+
 extern unsigned short myseqno;
 extern struct timeval seqno_time;
 extern int seqno_interval;

network.c

@@ -59,7 +59,7 @@ add_network(char *ifname)
     nets[numnets].sendbuf = NULL;
     nets[numnets].buffered = 0;
     nets[numnets].bucket_time = now.tv_sec;
-    nets[numnets].bucket = 0;
+    nets[numnets].bucket = BUCKET_TOKENS_MAX;
     nets[numnets].hello_seqno = (random() & 0xFFFF);
     numnets++;
     return &nets[numnets - 1];