From a71c3f3c1fd3f99dda004c32396a005c8a4df41d Mon Sep 17 00:00:00 2001
From: Jeremy Lakeman <Jeremy.Lakeman@gmail.com>
Date: Wed, 22 May 2013 11:57:38 +0930
Subject: [PATCH] Don't send broadcast payloads on interfaces with no
 neighbours

---
 overlay_queue.c | 19 ++++++++++++-------
 route_link.c    | 14 +++++++++++++-
 serval.h        |  1 +
 3 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/overlay_queue.c b/overlay_queue.c
index fb94bb27..a4e9ae10 100644
--- a/overlay_queue.c
+++ b/overlay_queue.c
@@ -200,7 +200,8 @@ int overlay_payload_enqueue(struct overlay_frame *p)
       // make sure there is an interface up that allows broadcasts
       for(i=0;i<OVERLAY_MAX_INTERFACES;i++){
 	if (overlay_interfaces[i].state==INTERFACE_STATE_UP
-	    && overlay_interfaces[i].send_broadcasts){
+	    && overlay_interfaces[i].send_broadcasts
+	    && link_state_interface_has_neighbour(&overlay_interfaces[i])){
 	  p->broadcast_sent_via[i]=0;
 	  drop=0;
 	}else
@@ -297,7 +298,8 @@ overlay_calc_queue_time(overlay_txqueue *queue, struct overlay_frame *frame){
     int i;
     for(i=0;i<OVERLAY_MAX_INTERFACES;i++)
     {
-      if (overlay_interfaces[i].state!=INTERFACE_STATE_UP)
+      if (overlay_interfaces[i].state!=INTERFACE_STATE_UP || 
+	  !link_state_interface_has_neighbour(&overlay_interfaces[i]))
 	continue;
       time_ms_t next_packet = limit_next_allowed(&overlay_interfaces[i].transfer_limit);
       if (next_allowed_packet==0||next_packet < next_allowed_packet)
@@ -398,7 +400,9 @@ overlay_stuff_packet(struct outgoing_packet *packet, overlay_txqueue *queue, tim
 	  int i, keep=0;
 	  for(i=0;i<OVERLAY_MAX_INTERFACES;i++)
 	  {
-	    if (overlay_interfaces[i].state!=INTERFACE_STATE_UP || frame->broadcast_sent_via[i])
+	    if (overlay_interfaces[i].state!=INTERFACE_STATE_UP || 
+	        frame->broadcast_sent_via[i] ||
+	        !link_state_interface_has_neighbour(&overlay_interfaces[i]))
 	      continue;
 	    keep=1;
 	    time_ms_t next_allowed = limit_next_allowed(&overlay_interfaces[i].transfer_limit);
@@ -490,18 +494,20 @@ overlay_stuff_packet(struct outgoing_packet *packet, overlay_txqueue *queue, tim
       // check if there is still a broadcast to be sent      
       for(i=0;i<OVERLAY_MAX_INTERFACES;i++)
       {
-	if (overlay_interfaces[i].state==INTERFACE_STATE_UP)
+	if (overlay_interfaces[i].state==INTERFACE_STATE_UP &&
+	    link_state_interface_has_neighbour(&overlay_interfaces[i])){
 	  if (!frame->broadcast_sent_via[i]){
 	    keep_payload=1;
 	    break;
 	  }
+	}
       }
     }
-    
+
     if (!keep_payload){
       frame = overlay_queue_remove(queue, frame);
       continue;
-    } 
+    }
     
   skip:
     // if we can't send the payload now, check when we should try next
@@ -547,7 +553,6 @@ overlay_fill_send_packet(struct outgoing_packet *packet, time_ms_t now) {
 static void overlay_send_packet(struct sched_ent *alarm){
   struct outgoing_packet packet;
   bzero(&packet, sizeof(struct outgoing_packet));
-  
   overlay_fill_send_packet(&packet, gettime_ms());
 }
 
diff --git a/route_link.c b/route_link.c
index c4cb3020..90c2930c 100644
--- a/route_link.c
+++ b/route_link.c
@@ -67,7 +67,7 @@ struct neighbour_link{
 
   char unicast;
   int ack_sequence;
-  uint32_t ack_mask;
+  uint64_t ack_mask;
 };
 
 struct neighbour{
@@ -655,6 +655,18 @@ struct neighbour_link * get_neighbour_link(struct neighbour *neighbour, struct o
   return link;
 }
 
+int link_state_interface_has_neighbour(struct overlay_interface *interface)
+{
+  struct neighbour *neighbour = neighbours;
+  while(neighbour){
+    if (neighbour->best_link && neighbour->best_link->interface == interface)
+      return 1;
+
+    neighbour = neighbour->_next;
+  }
+  return 0;
+}
+
 // track stats for receiving packets from this neighbour
 int link_received_packet(struct subscriber *subscriber, struct overlay_interface *interface, int sender_interface, int sender_seq, int unicast)
 {
diff --git a/serval.h b/serval.h
index 64146973..e3c343c3 100644
--- a/serval.h
+++ b/serval.h
@@ -835,6 +835,7 @@ void link_explained(struct subscriber *subscriber);
 void link_interface_down(struct overlay_interface *interface);
 int link_state_announce_links();
 int link_state_legacy_ack(struct overlay_frame *frame, time_ms_t now);
+int link_state_interface_has_neighbour(struct overlay_interface *interface);
 
 int generate_nonce(unsigned char *nonce,int bytes);