From b0c1b7b7b5fd295161164e9696673e482160941f Mon Sep 17 00:00:00 2001
From: Jonathan Bennett <jbennett@incomsystems.biz>
Date: Fri, 16 Aug 2024 10:10:08 -0500
Subject: [PATCH] MQTT PKI fixes

---
 src/mqtt/MQTT.cpp | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/mqtt/MQTT.cpp b/src/mqtt/MQTT.cpp
index 1d2d9bca0..d3a2bb92c 100644
--- a/src/mqtt/MQTT.cpp
+++ b/src/mqtt/MQTT.cpp
@@ -152,7 +152,7 @@ void MQTT::onReceive(char *topic, byte *payload, size_t length)
                     LOG_INFO("Ignoring downlink message we originally sent.\n");
             } else {
                 // Find channel by channel_id and check downlink_enabled
-                if ((strcmp(e.channel_id, "PKI") && e.packet) ||
+                if ((strcmp(e.channel_id, "PKI") == 0 && e.packet) ||
                     (strcmp(e.channel_id, channels.getGlobalId(ch.index)) == 0 && e.packet && ch.settings.downlink_enabled)) {
                     LOG_INFO("Received MQTT topic %s, len=%u\n", topic, length);
                     meshtastic_MeshPacket *p = packetPool.allocCopy(*e.packet);
@@ -163,7 +163,8 @@ void MQTT::onReceive(char *topic, byte *payload, size_t length)
                     }
 
                     // PKI messages get accepted even if we can't decrypt
-                    if (router && p->which_payload_variant == meshtastic_MeshPacket_encrypted_tag && p->channel == 0)
+                    if (router && p->which_payload_variant == meshtastic_MeshPacket_encrypted_tag &&
+                        strcmp(e.channel_id, "PKI") == 0)
                         router->enqueueReceivedMessage(p);
                     // ignore messages if we don't have the channel key
                     else if (router && perhapsDecode(p))
@@ -365,10 +366,12 @@ void MQTT::reconnect()
 void MQTT::sendSubscriptions()
 {
 #if HAS_NETWORKING
+    bool hasDownlink = false;
     size_t numChan = channels.getNumChannels();
     for (size_t i = 0; i < numChan; i++) {
         const auto &ch = channels.getByIndex(i);
         if (ch.settings.downlink_enabled) {
+            hasDownlink = true;
             std::string topic = cryptTopic + channels.getGlobalId(i) + "/#";
             LOG_INFO("Subscribing to %s\n", topic.c_str());
             pubSub.subscribe(topic.c_str(), 1); // FIXME, is QOS 1 right?
@@ -382,9 +385,11 @@ void MQTT::sendSubscriptions()
         }
     }
 #if !MESHTASTIC_EXCLUDE_PKI
-    std::string topic = cryptTopic + "PKI/#";
-    LOG_INFO("Subscribing to %s\n", topic.c_str());
-    pubSub.subscribe(topic.c_str(), 1);
+    if (hasDownlink) {
+        std::string topic = cryptTopic + "PKI/#";
+        LOG_INFO("Subscribing to %s\n", topic.c_str());
+        pubSub.subscribe(topic.c_str(), 1);
+    }
 #endif
 #endif
 }
@@ -496,7 +501,13 @@ void MQTT::onSend(const meshtastic_MeshPacket &mp, const meshtastic_MeshPacket &
 {
     if (mp.via_mqtt)
         return; // Don't send messages that came from MQTT back into MQTT
-
+    bool uplinkEnabled = false;
+    for (int i = 0; i <= 7; i++) {
+        if (channels.getByIndex(i).settings.uplink_enabled)
+            uplinkEnabled = true;
+    }
+    if (!uplinkEnabled)
+        return; // no channels have an uplink enabled
     auto &ch = channels.getByIndex(chIndex);
 
     if (mp_decoded.which_payload_variant != meshtastic_MeshPacket_decoded_tag) {
@@ -511,7 +522,7 @@ void MQTT::onSend(const meshtastic_MeshPacket &mp, const meshtastic_MeshPacket &
         return;
     }
 
-    if (ch.settings.uplink_enabled) {
+    if (ch.settings.uplink_enabled || mp.pki_encrypted) {
         const char *channelId = channels.getGlobalId(chIndex); // FIXME, for now we just use the human name for the channel
 
         meshtastic_ServiceEnvelope *env = mqttPool.allocZeroed();