Maintain ihu_interval for each neighbour.

message.c

@@ -135,6 +135,7 @@ parse_packet(const unsigned char *from, struct network *net,
                 if(plen == 0xFF || memcmp(myid, address, 16) == 0) {
                     neigh->txcost = metric;
                     neigh->ihu_time = now.tv_sec;
+                    neigh->ihu_interval = seqno;
                     update_neighbour_metric(neigh);
                 }
             } else if(type == 2) {

neighbour.c

@@ -108,6 +108,7 @@ add_neighbour(const unsigned char *id, const unsigned char *address,
     neigh->ihu_time = now.tv_sec;
     neigh->hello_time = zero;
     neigh->hello_interval = 0;
+    neigh->ihu_interval = 0;
     neigh->hello_seqno = -1;
     neigh->network = net;
     send_hello(net);

neighbour.h

@@ -30,6 +30,7 @@ struct neighbour {
     int ihu_time;
     struct timeval hello_time;
     unsigned short hello_interval; /* in centiseconds */
+    unsigned short ihu_interval;   /* in centiseconds */
     struct network *network;
 };