First tack at multihop requests.

babel.c

@@ -64,6 +64,8 @@ int wired_hello_interval = -1;
 int idle_hello_interval = -1;
 int update_interval = -1;
 
+int max_hopcount = 25;
+
 struct network nets[MAXNETS];
 int numnets = 0;
 
@@ -367,14 +369,14 @@ main(int argc, char **argv)
     /* Make some noise so others notice us */
     for(i = 0; i < numnets; i++) {
         send_hello(&nets[i]);
-        send_request(&nets[i], NULL);
+        send_request(&nets[i], NULL, 0);
     }
     for(i = 0; i < numnets; i++) {
         usleep(50000 + random() % 100000);
         flushbuf(&nets[i]);
         send_hello(&nets[i]);
         send_self_update(&nets[i], 0);
-        send_request(&nets[i], NULL);
+        send_request(&nets[i], NULL, 0);
     }
 
     debugf("Entering main loop.\n");
@@ -740,7 +742,7 @@ expire_routes(void)
 
         if(route->installed && route->refmetric < INFINITY) {
             if(route->time < now.tv_sec - MAX(5, route_timeout_delay - 25))
-                send_unicast_request(route->nexthop, route->dest);
+                send_unicast_request(route->nexthop, route->dest, 0);
         }
         i++;
     }

babel.h

@@ -96,5 +96,6 @@ extern int protocol_port;
 extern unsigned char protocol_group[16];
 extern int protocol_socket;
 extern int kernel_socket;
+extern int max_hopcount;
 
 void update_hello_interval(struct network *net);

message.c

@@ -294,13 +294,13 @@ send_hello(struct network *net)
 }
 
 void
-send_request(struct network *net, struct destination *dest)
+send_request(struct network *net, struct destination *dest, int hopcount)
 {
     int i;
 
     if(net == NULL) {
         for(i = 0; i < numnets; i++)
-            send_request(&nets[i], dest);
+            send_request(&nets[i], dest, hopcount);
         return;
     }
 
@@ -308,8 +308,14 @@ send_request(struct network *net, struct destination *dest)
            net->ifname, dest ? format_address(dest->address) : "::/0");
     start_message(net, 20);
     accumulate_byte(net, 1);
+    if(hopcount > 0 && dest) {
+        accumulate_byte(net, dest->seqno);
+        accumulate_byte(net, hopcount);
+    } else {
+        accumulate_byte(net, 0);
+        accumulate_byte(net, 0);
+    }
     accumulate_byte(net, 0);
-    accumulate_short(net, 0);
     accumulate_data(net, dest ? dest->address : zeroes, 16);
     schedule_flush(net);
 }
@@ -340,7 +346,8 @@ send_unicast_packet(struct neighbour *neigh, unsigned char *buf, int buflen)
 
 
 void
-send_unicast_request(struct neighbour *neigh, struct destination *dest)
+send_unicast_request(struct neighbour *neigh, struct destination *dest,
+                     int hopcount)
 {
     unsigned char buf[20];
 
@@ -350,8 +357,13 @@ send_unicast_request(struct neighbour *neigh, struct destination *dest)
            dest ? format_address(dest->address) : "::/0");
 
     buf[0] = 1;
-    buf[1] = 0;
-    buf[2] = 0;
+    if(hopcount > 0 && dest) {
+        buf[1] = dest->seqno;
+        buf[2] = hopcount;
+    } else {
+        buf[1] = 0;
+        buf[2] = 0;
+    }
     buf[3] = 0;
     if(dest == NULL)
         memset(buf + 4, 0, 16);

message.h

@@ -39,8 +39,10 @@ void parse_packet(const unsigned char *from, struct network *net,
                   const unsigned char *packet, int len);
 void flushbuf(struct network *net);
 void send_hello(struct network *net);
-void send_request(struct network *net, struct destination *dest);
-void send_unicast_request(struct neighbour *neigh, struct destination *dest);
+void send_request(struct network *net, struct destination *dest,
+                  int hopcount);
+void send_unicast_request(struct neighbour *neigh, struct destination *dest,
+                          int hopcount);
 void send_update(struct destination *dest, struct network *net);
 void send_self_update(struct network *net, int force_seqno);
 void send_self_retract(struct network *net);

neighbour.c

@@ -174,7 +174,7 @@ update_neighbour(struct neighbour *neigh, int hello, int hello_interval)
         if(dest)
             route = find_best_route(dest);
         if(!route || route->nexthop == neigh)
-            send_unicast_request(neigh, NULL);
+            send_unicast_request(neigh, NULL, 0);
     }
 }
 

route.c

@@ -100,7 +100,7 @@ flush_route(struct route *route)
                 dest->seqno = (dest->seqno + 1) & 0xFF;
             }
             send_update(route->dest, NULL);
-            send_request(NULL, route->dest);
+            send_request(NULL, route->dest, max_hopcount);
         }
     }
 }
@@ -431,6 +431,6 @@ send_triggered_update(struct route *route, int oldmetric)
     if(route->metric - oldmetric >= 384) {
         /* This route's metric has increased a lot -- let's hope we find
            something better */
-        send_request(NULL, route->dest);
+        send_request(NULL, route->dest, 0);
     }
 }