add want_ack support for broadcast packets

src/mesh/FloodingRouter.cpp

@@ -11,7 +11,7 @@ FloodingRouter::FloodingRouter() {}
  */
 ErrorCode FloodingRouter::send(MeshPacket *p)
 {
-    // Add any messages _we_ send to the seen message list
+    // Add any messages _we_ send to the seen message list (so we will ignore all retransmissions we see)
     wasSeenRecently(p); // FIXME, move this to a sniffSent method
 
     return Router::send(p);

src/mesh/ReliableRouter.cpp

@@ -33,7 +33,17 @@ ErrorCode ReliableRouter::send(MeshPacket *p)
  */
 void ReliableRouter::handleReceived(MeshPacket *p)
 {
-    if (p->to == getNodeNum()) { // ignore ack/nak/want_ack packets that are not address to us (for now)
+    NodeNum ourNode = getNodeNum();
+
+    if (p->from == ourNode && p->to == NODENUM_BROADCAST) {
+        // We are seeing someone rebroadcast one of our broadcast attempts.
+        // If this is the first time we saw this, cancel any retransmissions we have queued up and generate an internal ack for
+        // the original sending process.
+        if (stopRetransmission(p->from, p->id)) {
+            DEBUG_MSG("Someone is retransmitting for us, generate implicit ack");
+            sendAckNak(true, p->from, p->id);
+        }
+    } else if (p->to == ourNode) { // ignore ack/nak/want_ack packets that are not address to us (for now)
         if (p->want_ack) {
             sendAckNak(true, p->from, p->id);
         }
@@ -95,20 +105,22 @@ PendingPacket::PendingPacket(MeshPacket *p)
 /**
  * Stop any retransmissions we are doing of the specified node/packet ID pair
  */
-void ReliableRouter::stopRetransmission(NodeNum from, PacketId id)
+bool ReliableRouter::stopRetransmission(NodeNum from, PacketId id)
 {
     auto key = GlobalPacketId(from, id);
     stopRetransmission(key);
 }
 
-void ReliableRouter::stopRetransmission(GlobalPacketId key)
+bool ReliableRouter::stopRetransmission(GlobalPacketId key)
 {
     auto old = pending.find(key); // If we have an old record, someone messed up because id got reused
     if (old != pending.end()) {
         auto numErased = pending.erase(key);
         assert(numErased == 1);
         packetPool.release(old->second.packet);
-    }
+        return true;
+    } else
+        return false;
 }
 /**
  * Add p to the list of packets to retransmit occasionally.  We will free it once we stop retransmitting.

src/mesh/ReliableRouter.h

@@ -39,6 +39,12 @@ struct PendingPacket {
     /** Starts at NUM_RETRANSMISSIONS -1(normally 3) and counts down.  Once zero it will be removed from the list */
     uint8_t numRetransmissions;
 
+    /** True if we have started trying to find a route - for DSR usage
+     * While trying to find a route we don't actually send the data packet.  We just leave it here pending until
+     * we have a route or we've failed to find one.
+     */
+    bool wantRoute = false;
+
     PendingPacket() {}
     PendingPacket(MeshPacket *p);
 
@@ -98,9 +104,11 @@ class ReliableRouter : public FloodingRouter
 
     /**
      * Stop any retransmissions we are doing of the specified node/packet ID pair
+     *
+     * @return true if we found and removed a transmission with this ID
      */
-    void stopRetransmission(NodeNum from, PacketId id);
-    void stopRetransmission(GlobalPacketId p);
+    bool stopRetransmission(NodeNum from, PacketId id);
+    bool stopRetransmission(GlobalPacketId p);
 
     /**
      * Add p to the list of packets to retransmit occasionally.  We will free it once we stop retransmitting.