Add configurable max hops filter for auto-add contacts

Filter auto-add of new contacts by hop count (issues #1533, #1546).
Setting is configurable from the companion app via extended
CMD_SET/GET_AUTOADD_CONFIG protocol (0 = no limit, 1-63 = max hops).

Co-Authored-By: Claude Opus 4.6 <[email protected]>

examples/companion_radio/DataStore.cpp

@@ -229,6 +229,7 @@ void DataStore::loadPrefsInt(const char *filename, NodePrefs& _prefs, double& no
     file.read((uint8_t *)&_prefs.gps_enabled, sizeof(_prefs.gps_enabled));                 // 85
     file.read((uint8_t *)&_prefs.gps_interval, sizeof(_prefs.gps_interval));               // 86
     file.read((uint8_t *)&_prefs.autoadd_config, sizeof(_prefs.autoadd_config));           // 87
+    file.read((uint8_t *)&_prefs.autoadd_max_hops, sizeof(_prefs.autoadd_max_hops));       // 88
 
     file.close();
   }
@@ -265,6 +266,7 @@ void DataStore::savePrefs(const NodePrefs& _prefs, double node_lat, double node_
     file.write((uint8_t *)&_prefs.gps_enabled, sizeof(_prefs.gps_enabled));                 // 85
     file.write((uint8_t *)&_prefs.gps_interval, sizeof(_prefs.gps_interval));               // 86
     file.write((uint8_t *)&_prefs.autoadd_config, sizeof(_prefs.autoadd_config));           // 87
+    file.write((uint8_t *)&_prefs.autoadd_max_hops, sizeof(_prefs.autoadd_max_hops));      // 88
 
     file.close();
   }

examples/companion_radio/MyMesh.cpp

@@ -318,6 +318,10 @@ bool MyMesh::shouldOverwriteWhenFull() const {
   return (_prefs.autoadd_config & AUTO_ADD_OVERWRITE_OLDEST) != 0;
 }
 
+uint8_t MyMesh::getAutoAddMaxHops() const {
+  return _prefs.autoadd_max_hops;
+}
+
 void MyMesh::onContactOverwrite(const uint8_t* pub_key) {
     _store->deleteBlobByKey(pub_key, PUB_KEY_SIZE); // delete from storage
   if (_serial->isConnected()) {
@@ -1785,12 +1789,16 @@ void MyMesh::handleCmdFrame(size_t len) {
     }
   } else if (cmd_frame[0] == CMD_SET_AUTOADD_CONFIG) {
     _prefs.autoadd_config = cmd_frame[1];
+    if (len >= 3) {
+      _prefs.autoadd_max_hops = cmd_frame[2];
+    }
     savePrefs();
     writeOKFrame();
   } else if (cmd_frame[0] == CMD_GET_AUTOADD_CONFIG) {
     int i = 0;
     out_frame[i++] = RESP_CODE_AUTOADD_CONFIG;
     out_frame[i++] = _prefs.autoadd_config;
+    out_frame[i++] = _prefs.autoadd_max_hops;
     _serial->writeFrame(out_frame, i);
   } else if (cmd_frame[0] == CMD_GET_ALLOWED_REPEAT_FREQ) {
     int i = 0;

examples/companion_radio/MyMesh.h

@@ -119,6 +119,7 @@ protected:
   bool isAutoAddEnabled() const override;
   bool shouldAutoAddContactType(uint8_t type) const override;
   bool shouldOverwriteWhenFull() const override;
+  uint8_t getAutoAddMaxHops() const override;
   void onContactsFull() override;
   void onContactOverwrite(const uint8_t* pub_key) override;
   bool onContactPathRecv(ContactInfo& from, uint8_t* in_path, uint8_t in_path_len, uint8_t* out_path, uint8_t out_path_len, uint8_t extra_type, uint8_t* extra, uint8_t extra_len) override;

examples/companion_radio/NodePrefs.h

@@ -30,4 +30,5 @@ struct NodePrefs {  // persisted to file
   uint8_t autoadd_config;    // bitmask for auto-add contacts config
   uint8_t client_repeat;
   uint8_t path_hash_mode;    // which path mode to use when sending
+  uint8_t autoadd_max_hops;  // 0 = no limit, 1-63 = max hops for auto-add
 };

src/helpers/BaseChatMesh.cpp

@@ -141,6 +141,15 @@ void BaseChatMesh::onAdvertRecv(mesh::Packet* packet, const mesh::Identity& id,
       return;
     }
 
+    // check hop limit for new contacts (0 = no limit)
+    uint8_t max_hops = getAutoAddMaxHops();
+    if (max_hops > 0 && packet->getPathHashCount() > max_hops) {
+      ContactInfo ci;
+      populateContactFromAdvert(ci, id, parser, timestamp);
+      onDiscoveredContact(ci, true, packet->path_len, packet->path);       // let UI know
+      return;
+    }
+
     from = allocateContactSlot();
     if (from == NULL) {
       ContactInfo ci;

src/helpers/BaseChatMesh.h

@@ -98,6 +98,7 @@ protected:
   virtual bool shouldAutoAddContactType(uint8_t type) const { return true; }
   virtual void onContactsFull() {};
   virtual bool shouldOverwriteWhenFull() const { return false; }
+  virtual uint8_t getAutoAddMaxHops() const { return 0; }  // 0 = no limit, 1-63 = max hops for auto-add
   virtual void onContactOverwrite(const uint8_t* pub_key) {};
   virtual void onDiscoveredContact(ContactInfo& contact, bool is_new, uint8_t path_len, const uint8_t* path) = 0;
   virtual ContactInfo* processAck(const uint8_t *data) = 0;