feat: add path.hash.mode.min CLI command for repeaters

docs/cli_commands.md

@@ -442,7 +442,24 @@ This document provides an overview of CLI commands that can be sent to MeshCore
 
 **Note:** the 'path.hash.mode' sets the low-level ID/hash encoding size used when the repeater adverts. This setting has no impact on what packet ID/hash size this repeater forwards, all sizes should be forwarded on firmware >= 1.14. This feature was added in firmware 1.14
 
-**Temporary Note:** adverts with ID/hash sizes of 2 or 3 bytes may have limited flood propagation in your network while this feature is new as v1.13.0 firmware and older will drop packets with multibyte path ID/hashes as only 1-byte hashes are supported. Consider your install base of firmware >=1.14 has reached a criticality for effective network flooding before implementing higher ID/hash sizes. 
+**Temporary Note:** adverts with ID/hash sizes of 2 or 3 bytes may have limited flood propagation in your network while this feature is new as v1.13.0 firmware and older will drop packets with multibyte path ID/hashes as only 1-byte hashes are supported. Consider your install base of firmware >=1.14 has reached a criticality for effective network flooding before implementing higher ID/hash sizes.
+
+---
+
+#### View or change minimum path hash size for forwarded packets (repeaters only)
+**Usage:**
+- `get path.hash.mode.min`
+- `set path.hash.mode.min <value>`
+
+**Parameters:**
+- `value`: Minimum path hash mode (0-2)
+  - `0`: No minimum (forward all packets)
+  - `1`: Require hash size >= 2 bytes (drop 1-byte hashes)
+  - `2`: Require hash size >= 3 bytes (drop 1-2 byte hashes)
+
+**Default:** `0`
+
+**Note:** This setting only applies to repeaters and only affects flood packet forwarding. When set to a non-zero value, the repeater will drop flood packets whose embedded path hash size is smaller than the minimum.
 
 ---
 

docs/faq.md

@@ -299,7 +299,12 @@ However, with 1 byte, there are only 254 unique IDs (exclude 00 and FF which are
 Firmware version 1.14 and newer introduces the ability for repeaters to advert with 1-, 2-, or 3-byte adverts. Companions can also send out channel and direct messages with 1-, 2-, or 3-byte path. Adverts and messages sent in 1-byte path is compatible with repeater firmware older or newer than 1.14. They will travel up to 64 hops. 2-byte adverts and messages will travel up to 32 hops. 3-byte adverts and messages will travel up to 21 hops.
 
 ### 3.9.1. Q: **What path hash sizes will my repeater forward?**
-Repeaters running firmware 1.14+ repeat packets sent with 1-, 2-, or 3-byte path hash. Repeaters on firmware older than 1.14 only repeat 1-byte path hash packets and silently drop 2- and 3-byte packets.
+Repeaters running firmware 1.14+ repeat packets sent with 1-, 2-, or 3-byte path hash by default. Repeaters on firmware older than 1.14 only repeat 1-byte path hash packets and silently drop 2- and 3-byte packets.
+
+Repeaters can optionally enforce a minimum path hash size using the `set path.hash.mode.min <value>` CLI command:
+- `0`: No minimum (forward all packets, default)
+- `1`: Require hash size >= 2 bytes (drop 1-byte packets)
+- `2`: Require hash size >= 3 bytes (drop 1-2 byte packets)
 
 ### 3.9.2. Q: **What determines a packet's path hash size?**
 The original packet sender determines the path hash size. The most common original sender is a companion app. The other common original sender is a repeater, when it broadcasts its advert.

examples/simple_repeater/MyMesh.cpp

@@ -432,6 +432,7 @@ bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
     if (packet->getPathHashCount() >= _prefs.flood_max) return false;
     if (packet->getRouteType() == ROUTE_TYPE_FLOOD && packet->getPathHashCount() >= _prefs.flood_max_unscoped) return false;
     if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->getPathHashCount() >= _prefs.flood_max_advert) return false;
+    if (packet->getPathHashSize() < (_prefs.min_path_hash_mode + 1)) return false;
   }
   if (packet->isRouteFlood() && recv_pkt_region == NULL) {
     MESH_DEBUG_PRINTLN("allowPacketForward: unknown transport code, or wildcard not allowed for FLOOD packet");
@@ -892,6 +893,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_max = 64;
   _prefs.flood_max_unscoped = 64;
   _prefs.flood_max_advert = 8;
+  _prefs.min_path_hash_mode = 0; // default minimum (mode 0 = hash_size 1)
   _prefs.interference_threshold = 0; // disabled
 
   // bridge defaults

src/helpers/CommonCLI.cpp

@@ -91,7 +91,8 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
     file.read((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));   // 291
     file.read((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));       // 292
-    // next: 293
+    file.read((uint8_t *)&_prefs->min_path_hash_mode, sizeof(_prefs->min_path_hash_mode));   // 293
+    // next: 294
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -184,7 +185,8 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
     file.write((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));   // 291
     file.write((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));       // 292
-    // next: 293
+    file.write((uint8_t *)&_prefs->min_path_hash_mode, sizeof(_prefs->min_path_hash_mode));   // 293
+    // next: 294
 
     file.close();
   }
@@ -668,6 +670,15 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
     } else {
       strcpy(reply, "Error, must be 0,1, or 2");
     }
+  } else if (memcmp(config, "path.hash.mode.min ", 19) == 0) {
+    uint8_t mode = atoi(&config[19]);
+    if (mode < 3) {
+      _prefs->min_path_hash_mode = mode;
+      savePrefs();
+      strcpy(reply, "OK");
+    } else {
+      strcpy(reply, "Error, must be 0,1, or 2");
+    }
   } else if (memcmp(config, "loop.detect ", 12) == 0) {
     config += 12;
     uint8_t mode;
@@ -832,6 +843,8 @@ void CommonCLI::handleGetCmd(uint32_t sender_timestamp, char* command, char* rep
       sp++;
     }
     *reply = 0;  // set null terminator
+  } else if (memcmp(config, "path.hash.mode.min", 18) == 0) {
+    sprintf(reply, "> %d", (uint32_t)_prefs->min_path_hash_mode);
   } else if (memcmp(config, "path.hash.mode", 14) == 0) {
     sprintf(reply, "> %d", (uint32_t)_prefs->path_hash_mode);
   } else if (memcmp(config, "loop.detect", 11) == 0) {

src/helpers/CommonCLI.h

@@ -62,6 +62,7 @@ struct NodePrefs { // persisted to file
   char owner_info[120];
   uint8_t rx_boosted_gain; // power settings
   uint8_t path_hash_mode;   // which path mode to use when sending
+  uint8_t min_path_hash_mode; // minimum path hash size to forward (0=disabled)
   uint8_t loop_detect;
 };