From 5c512f65e9b175110a268c1690da92c54a15f8e3 Mon Sep 17 00:00:00 2001
From: dvdrw <admin@dvdrw.dev>
Date: Wed, 13 May 2026 18:08:36 +0200
Subject: [PATCH] fix: mdns lookup failing due to early free

---
 main/main.c | 54 ++++++++++++++++++++++++++---------------------------
 1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/main/main.c b/main/main.c
index 994820c..c8582e1 100644
--- a/main/main.c
+++ b/main/main.c
@@ -8,7 +8,6 @@
 #include "esp_event.h"
 #include "esp_netif.h"
 #include "esp_log.h"
-#include "esp_bt.h"
 #include "mdns.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/event_groups.h"
@@ -48,15 +47,8 @@ static void on_ble_scan_result(const char *tag_id, int8_t rssi)
 
 static void wifi_init_sta(void)
 {
-    esp_netif_create_default_wifi_sta();
-    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
-    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
-
     esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, wifi_event_handler, NULL);
     esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, wifi_event_handler, NULL);
-
-    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
-    ESP_ERROR_CHECK(esp_wifi_start());
     ESP_ERROR_CHECK(esp_wifi_connect());
 }
 
@@ -75,14 +67,24 @@ static bool resolve_mqtt_broker_mdns(char *host_out, size_t host_len, uint16_t *
 
     mdns_result_t *r = results;
     while (r) {
-        if (r->hostname && r->port) {
-            strncpy(host_out, r->hostname, host_len - 1);
-            *port_out = r->port;
-            
-            ESP_LOGI(TAG, "mDNS found broker: %s:%u", host_out, *port_out);
-            
-            found = true;
-            goto free_results;
+        if (r->port) {
+            if (r->addr) {
+                snprintf(host_out, host_len, IPSTR, IP2STR(&r->addr->addr.u_addr.ip4));
+                *port_out = r->port;
+                ESP_LOGI(TAG, "mDNS found broker: %s:%u", host_out, *port_out);
+                found = true;
+                goto free_results;
+            } else if (r->hostname) {
+                esp_ip4_addr_t ip4;
+                if (mdns_query_a(r->hostname, MDNS_QUERY_TIMEOUT_MS, &ip4) == ESP_OK) {
+                    snprintf(host_out, host_len, IPSTR, IP2STR(&ip4));
+                    *port_out = r->port;
+                    ESP_LOGI(TAG, "mDNS found broker: %s:%u", host_out, *port_out);
+                    found = true;
+                    goto free_results;
+                }
+                ESP_LOGW(TAG, "mDNS A query for %s failed", r->hostname);
+            }
         }
         r = r->next;
     }
@@ -106,21 +108,17 @@ void app_main(void)
 
     s_evt = xEventGroupCreate();
 
-    // Provisioning
+    /* WiFi hardware must be up before the provisioning manager runs */
+    esp_netif_create_default_wifi_sta();
+    wifi_init_config_t wcfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&wcfg));
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+    ESP_ERROR_CHECK(esp_wifi_start());
+
     if (!config_store_is_provisioned()) {
         ESP_LOGI(TAG, "Not provisioned - starting BLE provisioning");
-
-        /* WiFi must be started (STA mode) before provisioning manager */
-        esp_netif_create_default_wifi_sta();
-        wifi_init_config_t wcfg = WIFI_INIT_CONFIG_DEFAULT();
-        ESP_ERROR_CHECK(esp_wifi_init(&wcfg));
-        ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
-        ESP_ERROR_CHECK(esp_wifi_start());
-
         provisioning_run();  /* blocks until complete */
-
-        /* Release BT memory now that provisioning used it; we reinit below for scanning */
-        esp_bt_mem_release(ESP_BT_MODE_BTDM);
+        /* BT memory released by NETWORK_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BTDM */
     }
 
     // connect to wifi