From 6f1e01a750647273d107db3cee0198c75fefa5ae Mon Sep 17 00:00:00 2001 From: Matthias Wientapper Date: Wed, 7 Jan 2026 21:24:25 +0100 Subject: [PATCH 1/3] Limit flood advert packet forwarding, implements #1223 --- examples/simple_repeater/MyMesh.cpp | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/examples/simple_repeater/MyMesh.cpp b/examples/simple_repeater/MyMesh.cpp index 81c1dcb4..9b958b09 100644 --- a/examples/simple_repeater/MyMesh.cpp +++ b/examples/simple_repeater/MyMesh.cpp @@ -403,6 +403,14 @@ bool MyMesh::allowPacketForward(const mesh::Packet *packet) { MESH_DEBUG_PRINTLN("allowPacketForward: unknown transport code, or wildcard not allowed for FLOOD 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 + double_t roll_dice = (double)rand() / RAND_MAX; + double_t forw_prob = pow(0.308, packet->path_len - 1); + if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood() && roll_dice > forw_prob) + return false; + + // all other packets return true; } From 3088d1862a9bd6a62c7d6cb94c847186d69b5209 Mon Sep 17 00:00:00 2001 From: Matthias Wientapper Date: Fri, 9 Jan 2026 20:47:09 +0100 Subject: [PATCH 2/3] Limit flood advert packet forwarding for roomservers as well --- examples/simple_room_server/MyMesh.cpp | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/examples/simple_room_server/MyMesh.cpp b/examples/simple_room_server/MyMesh.cpp index 5451505a..1e2e763f 100644 --- a/examples/simple_room_server/MyMesh.cpp +++ b/examples/simple_room_server/MyMesh.cpp @@ -277,6 +277,15 @@ 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; + + // 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 + double_t roll_dice = (double)rand() / RAND_MAX; + double_t forw_prob = pow(0.308, packet->path_len - 1); + if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood() && roll_dice > forw_prob) + return false; + + // all other packets return true; } From 516d784087867babf0397fe462cf8f37c4419fd4 Mon Sep 17 00:00:00 2001 From: Matthias Wientapper Date: Tue, 13 Jan 2026 23:06:27 +0100 Subject: [PATCH 3/3] Add cli config flood.advert.base 0 = forwarding flood adverts off 1 = forwarding flood adverts on (unrestricted) 0.308 (default) = prob. forwarding according to #1338 --- examples/simple_repeater/MyMesh.cpp | 3 ++- examples/simple_room_server/MyMesh.cpp | 3 ++- src/helpers/CommonCLI.cpp | 21 +++++++++++++++++++-- src/helpers/CommonCLI.h | 1 + 4 files changed, 24 insertions(+), 4 deletions(-) diff --git a/examples/simple_repeater/MyMesh.cpp b/examples/simple_repeater/MyMesh.cpp index 9b958b09..1ee9182d 100644 --- a/examples/simple_repeater/MyMesh.cpp +++ b/examples/simple_repeater/MyMesh.cpp @@ -406,7 +406,7 @@ bool MyMesh::allowPacketForward(const mesh::Packet *packet) { // 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 double_t roll_dice = (double)rand() / RAND_MAX; - double_t forw_prob = pow(0.308, packet->path_len - 1); + double_t forw_prob = pow(_prefs.flood_advert_base, packet->path_len - 1); if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood() && roll_dice > forw_prob) return false; @@ -847,6 +847,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc _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_base = 0.308f; _prefs.flood_max = 64; _prefs.interference_threshold = 0; // disabled diff --git a/examples/simple_room_server/MyMesh.cpp b/examples/simple_room_server/MyMesh.cpp index 1e2e763f..d53e5bbf 100644 --- a/examples/simple_room_server/MyMesh.cpp +++ b/examples/simple_room_server/MyMesh.cpp @@ -281,7 +281,7 @@ bool MyMesh::allowPacketForward(const mesh::Packet *packet) { // 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 double_t roll_dice = (double)rand() / RAND_MAX; - double_t forw_prob = pow(0.308, packet->path_len - 1); + double_t forw_prob = pow(_prefs.flood_advert_base, packet->path_len - 1); if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood() && roll_dice > forw_prob) return false; @@ -624,6 +624,7 @@ 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 #ifdef ROOM_PASSWORD diff --git a/src/helpers/CommonCLI.cpp b/src/helpers/CommonCLI.cpp index e20bbb1c..b4b21a80 100644 --- a/src/helpers/CommonCLI.cpp +++ b/src/helpers/CommonCLI.cpp @@ -82,7 +82,9 @@ 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 - // 290 + file.read((uint8_t *)&_prefs->flood_advert_base, sizeof(_prefs->flood_advert_base)); // 290 + + // 294 // sanitise bad pref values _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f); @@ -110,6 +112,8 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) { _prefs->gps_enabled = constrain(_prefs->gps_enabled, 0, 1); _prefs->advert_loc_policy = constrain(_prefs->advert_loc_policy, 0, 2); + _prefs->flood_advert_base = constrain(_prefs->flood_advert_base, 0, 1); + file.close(); } } @@ -168,7 +172,9 @@ 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 - // 290 + file.write((uint8_t *)&_prefs->flood_advert_base, sizeof(_prefs->flood_advert_base)); // 290 + + // 294 file.close(); } @@ -385,6 +391,8 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch } else { sprintf(reply, "> %.3f", adc_mult); } + } else if (memcmp(config, "flood.advert.base", 17) == 0) { + sprintf(reply, "> %s", StrHelper::ftoa(_prefs->flood_advert_base)); // Power management commands } else if (memcmp(config, "pwrmgt.support", 14) == 0) { #ifdef NRF52_POWER_MANAGEMENT @@ -642,6 +650,15 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch _prefs->adc_multiplier = 0.0f; strcpy(reply, "Error: unsupported by this board"); }; + } else if (memcmp(config, "flood.advert.base ", 18) == 0) { + float f = atof(&config[18]); + if((f > 0) || (f<1)) { + _prefs->flood_advert_base = f; + savePrefs(); + strcpy(reply, "OK"); + } else { + strcpy(reply, "Error: base must be between 0 and 1"); + } } else { sprintf(reply, "unknown config: %s", config); } diff --git a/src/helpers/CommonCLI.h b/src/helpers/CommonCLI.h index 1e454ec2..57209a04 100644 --- a/src/helpers/CommonCLI.h +++ b/src/helpers/CommonCLI.h @@ -36,6 +36,7 @@ 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)