pr1810, modify to not completely block flood adverts

Fix pow() and rand() are calculated for every forwarded packet, but we only need it for flood advert. Also fixes 'paket' typo.

Co-authored-by: Wessel <wessel@weebl.me>

README.md

@@ -1,3 +1,18 @@
+
+## About MeshCore-Evo
+
+This is a friendly fork of the MeshCore project. 
+Its aim is to provide repeater firmwares with a few additional pending upstream PRs/improvements (i.e. PRs/improvements that are available to the MeshCore project but have not yet been merged in the upstream repo or PRs that might never be merged upstream for some reason).
+These changes are intended to help mitigating challenges in big or dense meshes, e.g.:
+
+- Dealing with flood advert traffic
+- improving `denyf *` handling
+
+This list might change any time.
+Refer to the [release notes](https://github.com/mattzzw/MeshCore-Evo/releases) for an up-to-date list of the applied changes.
+
+
+
 ## About MeshCore
 
 MeshCore is a lightweight, portable C++ library that enables multi-hop packet routing for embedded projects using LoRa and other packet radios. It is designed for developers who want to create resilient, decentralized communication networks that work without the internet.

examples/companion_radio/MyMesh.cpp

@@ -258,7 +258,7 @@ float MyMesh::getAirtimeBudgetFactor() const {
 }
 
 int MyMesh::getInterferenceThreshold() const {
-  return 0; // disabled for now, until currentRSSI() problem is resolved
+  return 1; // non-zero enables hardware CAD (Channel Activity Detection) before TX
 }
 
 int MyMesh::calcRxDelay(float score, uint32_t air_time) const {

examples/simple_repeater/MyMesh.cpp

@@ -447,6 +447,15 @@ bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
       return false;
     }
   }
+  // Limit flood advert paket forwarding using a probabilistic reduction defined by P(h) = 0.308^(hops-1)
+  // https://github.com/meshcore-dev/MeshCore/issues/1223
+  if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood()) {
+    double roll_dice = (double)rand() / RAND_MAX;
+    double forw_prob = pow(_prefs.flood_advert_base, packet->path_len - 1);
+    if (roll_dice > forw_prob)
+      return false;
+  }
+
   return true;
 }
 
@@ -550,7 +559,9 @@ bool MyMesh::filterRecvFloodPacket(mesh::Packet* pkt) {
   if (pkt->getRouteType() == ROUTE_TYPE_TRANSPORT_FLOOD) {
     recv_pkt_region = region_map.findMatch(pkt, REGION_DENY_FLOOD);
   } else if (pkt->getRouteType() == ROUTE_TYPE_FLOOD) {
-    if (region_map.getWildcard().flags & REGION_DENY_FLOOD) {
+      if ((pkt->getPayloadType() == PAYLOAD_TYPE_GRP_TXT ||
+           pkt->getPayloadType() == PAYLOAD_TYPE_GRP_DATA) &&
+          region_map.getWildcard().flags & REGION_DENY_FLOOD) {
       recv_pkt_region = NULL;
     } else {
       recv_pkt_region =  &region_map.getWildcard();
@@ -884,9 +895,10 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.cr = LORA_CR;
   _prefs.tx_power_dbm = LORA_TX_POWER;
   _prefs.advert_interval = 1;        // default to 2 minutes for NEW installs
-  _prefs.flood_advert_interval = 12; // 12 hours
+  _prefs.flood_advert_interval = 0;  // disabled
+  _prefs.flood_advert_base = 0.308f;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 0; // disabled
+  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
 
   // bridge defaults
   _prefs.bridge_enabled = 1;    // enabled

examples/simple_room_server/MyMesh.cpp

@@ -282,7 +282,17 @@ uint32_t MyMesh::getDirectRetransmitDelay(const mesh::Packet *packet) {
 
 bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
   if (_prefs.disable_fwd) return false;
-  if (packet->isRouteFlood() && packet->getPathHashCount() >= _prefs.flood_max) return false;
+  if (packet->isRouteFlood() && packet->path_len >= _prefs.flood_max) return false;
+
+  // Limit flood advert packet forwarding using a probabilistic reduction defined by P(h) = base^(hops-1)
+  // https://github.com/meshcore-dev/MeshCore/issues/1223
+  if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood()) {
+    double roll_dice = (double)rand() / RAND_MAX;
+    double forw_prob = pow(_prefs.flood_advert_base, packet->path_len - 1);
+    if (roll_dice > forw_prob)
+      return false;
+  }
+
   return true;
 }
 
@@ -642,8 +652,9 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.disable_fwd = 1;
   _prefs.advert_interval = 1;        // default to 2 minutes for NEW installs
   _prefs.flood_advert_interval = 12; // 12 hours
+  _prefs.flood_advert_base = 0.308f;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 0; // disabled
+  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
 #ifdef ROOM_PASSWORD
   StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
 #endif

examples/simple_sensor/SensorMesh.cpp

@@ -725,7 +725,7 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.flood_advert_interval = 0;   // disabled
   _prefs.disable_fwd = true;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 0;  // disabled
+  _prefs.interference_threshold = 1;  // non-zero enables hardware CAD before TX
 
   // GPS defaults
   _prefs.gps_enabled = 0;

platformio.ini

@@ -28,6 +28,7 @@ build_flags = -w -DNDEBUG -DRADIOLIB_STATIC_ONLY=1 -DRADIOLIB_GODMODE=1
   -D LORA_FREQ=869.618
   -D LORA_BW=62.5
   -D LORA_SF=8
+  -D LORA_CR=8
   -D ENABLE_ADVERT_ON_BOOT=1
   -D ENABLE_PRIVATE_KEY_IMPORT=1   ; NOTE: comment these out for more secure firmware
   -D ENABLE_PRIVATE_KEY_EXPORT=1

src/helpers/CommonCLI.cpp

@@ -88,8 +88,8 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read((uint8_t *)&_prefs->discovery_mod_timestamp, sizeof(_prefs->discovery_mod_timestamp)); // 162
     file.read((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.read((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
-    file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
+    file.read((uint8_t *)&_prefs->flood_advert_base, sizeof(_prefs->flood_advert_base));           // 290
-    // next: 291
+    file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 294
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -119,6 +119,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
 
     // sanitise settings
     _prefs->rx_boosted_gain = constrain(_prefs->rx_boosted_gain, 0, 1); // boolean
+    _prefs->flood_advert_base = constrain(_prefs->flood_advert_base, 0, 1);
 
     file.close();
   }
@@ -179,8 +180,8 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->discovery_mod_timestamp, sizeof(_prefs->discovery_mod_timestamp)); // 162
     file.write((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.write((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
-    file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
+    file.write((uint8_t *)&_prefs->flood_advert_base, sizeof(_prefs->flood_advert_base));          // 290
-    // next: 291
+    file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 294
 
     file.close();
   }
@@ -607,6 +608,15 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
     } else {
       strcpy(reply, "Error, max 64");
     }
+  } else if (memcmp(config, "flood.advert.base ", 18) == 0) {
+    float f = atof(&config[18]);
+    if (f >= 0.0f && f <= 1.0f) {
+      _prefs->flood_advert_base = f;
+      savePrefs();
+      strcpy(reply, "OK");
+    } else {
+      strcpy(reply, "Error: base must be between 0 and 1");
+    }
   } else if (memcmp(config, "direct.txdelay ", 15) == 0) {
     float f = atof(&config[15]);
     if (f >= 0) {
@@ -784,6 +794,8 @@ void CommonCLI::handleGetCmd(uint32_t sender_timestamp, char* command, char* rep
     sprintf(reply, "> %s", StrHelper::ftoa(_prefs->tx_delay_factor));
   } else if (memcmp(config, "flood.max", 9) == 0) {
     sprintf(reply, "> %d", (uint32_t)_prefs->flood_max);
+  } else if (memcmp(config, "flood.advert.base", 17) == 0) {
+    sprintf(reply, "> %s", StrHelper::ftoa(_prefs->flood_advert_base));
   } else if (memcmp(config, "direct.txdelay", 14) == 0) {
     sprintf(reply, "> %s", StrHelper::ftoa(_prefs->direct_tx_delay_factor));
   } else if (memcmp(config, "owner.info", 10) == 0) {

src/helpers/CommonCLI.h

@@ -42,6 +42,7 @@ struct NodePrefs { // persisted to file
   uint8_t flood_max;
   uint8_t interference_threshold;
   uint8_t agc_reset_interval; // secs / 4
+  float flood_advert_base;
   // Bridge settings
   uint8_t bridge_enabled; // boolean
   uint16_t bridge_delay;  // milliseconds (default 500 ms)

src/helpers/radiolib/RadioLibWrappers.cpp

@@ -168,10 +168,20 @@ void RadioLibWrapper::onSendFinished() {
   state = STATE_IDLE;
 }
 
+int16_t RadioLibWrapper::performChannelScan() {
+  return _radio->scanChannel();
+}
+
 bool RadioLibWrapper::isChannelActive() {
-  return _threshold == 0 
+  if (_threshold == 0) return false;    // interference check is disabled
-          ? false    // interference check is disabled
+
-          : getCurrentRSSI() > _noise_floor + _threshold;
+  int16_t result = performChannelScan();
+  // scanChannel() triggers DIO interrupt (CAD done) which sets STATE_INT_READY
+  // via setFlag() ISR. Clear it before restarting RX so recvRaw() doesn't
+  // try to read a non-existent packet and count a spurious recv error.
+  state = STATE_IDLE;
+  startRecv();
+  return result != RADIOLIB_CHANNEL_FREE;
 }
 
 float RadioLibWrapper::getLastRSSI() const {

src/helpers/radiolib/RadioLibWrappers.h

@@ -38,6 +38,7 @@ public:
   }
 
   virtual float getCurrentRSSI() =0;
+  virtual int16_t performChannelScan();
 
   int getNoiseFloor() const override { return _noise_floor; }
   void triggerNoiseFloorCalibrate(int threshold) override;

variants/heltec_t114/variant.h

@@ -32,7 +32,7 @@
 
 // Power management boot protection threshold (millivolts)
 // Set to 0 to disable boot protection
-#define PWRMGT_VOLTAGE_BOOTLOCK 3300   // Won't boot below this voltage (mV)
+#define PWRMGT_VOLTAGE_BOOTLOCK 0   // Won't boot below this voltage (mV)
 // LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
 // AIN2 = P0.04 = BATTERY_PIN / PIN_VBAT_READ
 #define PWRMGT_LPCOMP_AIN 2

variants/rak4631/variant.h

@@ -106,7 +106,7 @@ extern "C"
 
 // Power management boot protection threshold (millivolts)
 // Set to 0 to disable boot protection
-#define PWRMGT_VOLTAGE_BOOTLOCK 3300   // Won't boot below this voltage (mV)
+#define PWRMGT_VOLTAGE_BOOTLOCK 0   // Won't boot below this voltage (mV)
 // LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
 // AIN3 = P0.05 = PIN_A0 / PIN_VBAT_READ
 #define PWRMGT_LPCOMP_AIN 3

variants/xiao_nrf52/variant.h

@@ -77,7 +77,7 @@ static const uint8_t D10 = 10;
 
 // Power management boot protection threshold (millivolts)
 // Set to 0 to disable boot protection
-#define PWRMGT_VOLTAGE_BOOTLOCK    3300   // Won't boot below this voltage
+#define PWRMGT_VOLTAGE_BOOTLOCK    0   // Won't boot below this voltage
 
 // LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
 #define PWRMGT_LPCOMP_AIN           7     // AIN7 = P0.31 = PIN_VBAT