From 759567917a449462d3bf767d66c865a92cbe8660 Mon Sep 17 00:00:00 2001
From: liamcottle <liam@liamcottle.com>
Date: Sat, 28 Sep 2024 09:47:26 +1200
Subject: [PATCH] add cli flag to drop portnums that don't have the bitfield
 available

---
 src/mqtt.js | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/mqtt.js b/src/mqtt.js
index d60f4ab..44353a1 100644
--- a/src/mqtt.js
+++ b/src/mqtt.js
@@ -106,6 +106,13 @@ const optionsList = [
         type: Boolean,
         description: "This option will drop all packets that have 'OK to MQTT' set to false.",
     },
+    {
+        name: "drop-portnums-without-bitfield",
+        type: Number,
+        multiple: true,
+        typeLabel: '<portnum> ...',
+        description: "If provided, packets with these portnums will be dropped if they don't have a bitfield. (bitfield available from firmware v2.5+)",
+    },
     {
         name: "purge-interval-seconds",
         type: Number,
@@ -206,6 +213,7 @@ const decryptionKeys = options["decryption-keys"] ?? [
     "1PG7OiApB1nwvP+rz05pAQ==", // add default "AQ==" decryption key
 ];
 const dropPacketsNotOkToMqtt = options["drop-packets-not-ok-to-mqtt"] ?? false;
+const dropPortnumsWithoutBitfield = options["drop-portnums-without-bitfield"] ?? null;
 const purgeIntervalSeconds = options["purge-interval-seconds"] ?? 10;
 const purgeNodesUnheardForSeconds = options["purge-nodes-unheard-for-seconds"] ?? null;
 const purgeDeviceMetricsAfterSeconds = options["purge-device-metrics-after-seconds"] ?? null;
@@ -644,6 +652,9 @@ client.on("message", async (topic, message) => {
             }
         }
 
+        // get portnum from packet
+        const portnum = envelope.packet?.decoded?.portnum;
+
         // check if we can see the decrypted packet data, so we can see if it has the "OK to MQTT" bitfield flag set
         if(envelope.packet.decoded != null){
 
@@ -663,6 +674,17 @@ client.on("message", async (topic, message) => {
 
             }
 
+            // if bitfield is not available for this packet, check if we want to drop this portnum
+            if(bitfield == null){
+
+                // drop packet if portnum is in drop list
+                // this is useful for dropping specific packet types from firmware older than v2.5
+                if(dropPortnumsWithoutBitfield != null && dropPortnumsWithoutBitfield.includes(portnum)){
+                    return;
+                }
+
+            }
+
         }
 
         // create service envelope in db
@@ -700,7 +722,6 @@ client.on("message", async (topic, message) => {
         }
 
         const logKnownPacketTypes = false;
-        const portnum = envelope.packet?.decoded?.portnum;
 
         // if allowed portnums are configured, ignore portnums that are not in the list
         if(allowedPortnums != null && !allowedPortnums.includes(portnum)){