From 7b4f5fa418cae3beceeb3c2b7220439901ed0f4d Mon Sep 17 00:00:00 2001
From: medentem <info@medentem.com>
Date: Tue, 7 Jan 2025 14:52:12 -0600
Subject: [PATCH] if we have no knowledge of a direct neighbor yet, we fallback
 to broadcast

---
 src/mesh/FloodingRouter.cpp |  4 ++--
 src/mesh/NodeDB.cpp         | 20 ++++++++++----------
 src/mesh/NodeDB.h           |  4 ++--
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/src/mesh/FloodingRouter.cpp b/src/mesh/FloodingRouter.cpp
index 85b620efe..81098fbca 100644
--- a/src/mesh/FloodingRouter.cpp
+++ b/src/mesh/FloodingRouter.cpp
@@ -168,10 +168,10 @@ float FloodingRouter::calculateForwardProbability(const CoverageFilter &incoming
     return 1.0f;
 #endif
     // If we are a router or repeater, always forward because it's assumed these are in the most advantageous locations
-    // or if we haven't heard from any other nodes within the stale coverage time, fall back to always forward
+    // or if we haven't heard from any other nodes directly within the stale coverage time, fall back to always forward
     if (config.device.role == meshtastic_Config_DeviceConfig_Role_ROUTER ||
         config.device.role == meshtastic_Config_DeviceConfig_Role_REPEATER ||
-        nodeDB->secondsSinceLastNodeHeard() >= STALE_COVERAGE_SECONDS) {
+        nodeDB->secondsSinceLastDirectNeighborHeard() >= STALE_COVERAGE_SECONDS) {
         return 1.0f;
     }
 
diff --git a/src/mesh/NodeDB.cpp b/src/mesh/NodeDB.cpp
index a43c6f87b..9b67f26fa 100644
--- a/src/mesh/NodeDB.cpp
+++ b/src/mesh/NodeDB.cpp
@@ -936,20 +936,20 @@ std::vector<NodeNum> NodeDB::getCoveredNodes(uint32_t timeWindowSecs)
     return recentNeighbors;
 }
 
-uint32_t NodeDB::secondsSinceLastNodeHeard()
+uint32_t NodeDB::secondsSinceLastDirectNeighborHeard()
 {
-    // If maxLastHeard_ == 0, we have not heard from any remote node
-    if (maxLastHeard_ == 0) {
+    // If maxLastHeardDirectNeighbor_ == 0, we have not heard from any direct neighbors
+    if (maxLastHeardDirectNeighbor_ == 0) {
         return UINT32_MAX;
     }
 
     uint32_t now = getTime();
     // If the clock isn’t set or has jumped backwards, clamp to 0
-    if (now < maxLastHeard_) {
+    if (now < maxLastHeardDirectNeighbor_) {
         return 0;
     }
 
-    return (now - maxLastHeard_);
+    return (now - maxLastHeardDirectNeighbor_);
 }
 
 void NodeDB::cleanupMeshDB()
@@ -960,8 +960,8 @@ void NodeDB::cleanupMeshDB()
 
     for (int i = 0; i < numMeshNodes; i++) {
         if (meshNodes->at(i).has_user) {
-            if (meshNodes->at(i).last_heard > maxLastHeard_) {
-                maxLastHeard_ = meshNodes->at(i).last_heard;
+            if (meshNodes->at(i).has_hops_away && meshNodes->at(i).hops_away == 0 && meshNodes->at(i).last_heard > maxLastHeardDirectNeighbor_) {
+                maxLastHeardDirectNeighbor_ = meshNodes->at(i).last_heard;
             }
             if (meshNodes->at(i).user.public_key.size > 0) {
                 if (memfll(meshNodes->at(i).user.public_key.bytes, 0, meshNodes->at(i).user.public_key.size)) {
@@ -1554,9 +1554,6 @@ void NodeDB::updateFrom(const meshtastic_MeshPacket &mp)
 
         if (mp.rx_time) { // if the packet has a valid timestamp use it to update our last_heard
             info->last_heard = mp.rx_time;
-            if (info->last_heard > maxLastHeard_) {
-                maxLastHeard_ = info->last_heard;
-            }
         }
 
         if (mp.rx_snr)
@@ -1568,6 +1565,9 @@ void NodeDB::updateFrom(const meshtastic_MeshPacket &mp)
         if (mp.hop_start != 0 && mp.hop_limit <= mp.hop_start) {
             info->has_hops_away = true;
             info->hops_away = mp.hop_start - mp.hop_limit;
+            if (info->hops_away == 0 && info->last_heard && info->last_heard > maxLastHeardDirectNeighbor_) {
+                maxLastHeardDirectNeighbor_ = info->last_heard;
+            }
         }
     }
 }
diff --git a/src/mesh/NodeDB.h b/src/mesh/NodeDB.h
index a554e546d..8caa5ce1f 100644
--- a/src/mesh/NodeDB.h
+++ b/src/mesh/NodeDB.h
@@ -177,11 +177,11 @@ class NodeDB
      */
     std::vector<NodeNum> getCoveredNodes(uint32_t timeWindowSecs);
 
-    uint32_t secondsSinceLastNodeHeard();
+    uint32_t secondsSinceLastDirectNeighborHeard();
 
   private:
     uint32_t lastNodeDbSave = 0; // when we last saved our db to flash
-    uint32_t maxLastHeard_ = 0;  // the most recent last_heard value we've seen
+    uint32_t maxLastHeardDirectNeighbor_ = 0;  // the most recent last_heard value we've seen
 
     /// Find a node in our DB, create an empty NodeInfoLite if missing
     meshtastic_NodeInfoLite *getOrCreateMeshNode(NodeNum n);