app_wifi: Add an option to reset prov state machine on failure

Earlier, a reset and reboot were required if wrong Wi-Fi credentials
were given during provisioning. With this change, based on some
configured number of reconnection attempts, the firmware will go back into
provisioning mode.

Author: shahpiyushv

examples/common/app_wifi/Kconfig.projbuild

@@ -25,6 +25,24 @@ menu "ESP RainMaker App Wi-Fi Provisioning"
         default 1 if APP_WIFI_PROV_TRANSPORT_SOFTAP
         default 2 if APP_WIFI_PROV_TRANSPORT_BLE
 
+    config APP_WIFI_RESET_PROV_ON_FAILURE
+        bool
+        default y
+        prompt "Reset provisioned credentials and state machine after session failure"
+        help
+            Enable reseting provisioned credentials and state machine after session failure.
+            This will restart the provisioning service after retries are exhausted.
+
+    config APP_WIFI_PROV_MAX_RETRY_CNT
+        int
+        default 5
+        prompt "Max retries before reseting provisioning state machine"
+        depends on APP_WIFI_RESET_PROV_ON_FAILURE
+        help
+            Set the Maximum retry to avoid reconnecting to an inexistent AP or if credentials
+            are misconfigured. Provisioned credentials are erased and internal state machine
+            is reset after this threshold is reached.
+
     config APP_WIFI_SHOW_DEMO_INTRO_TEXT
         bool "Show intro text for demos"
         default n

examples/common/app_wifi/app_wifi.c

@@ -128,6 +128,9 @@ static void app_wifi_print_qr(const char *name, const char *pop, const char *tra
 static void event_handler(void* arg, esp_event_base_t event_base,
                           int32_t event_id, void* event_data)
 {
+#ifdef CONFIG_APP_WIFI_RESET_PROV_ON_FAILURE
+    static int retries = 0;
+#endif
     if (event_base == WIFI_PROV_EVENT) {
         switch (event_id) {
             case WIFI_PROV_START:
@@ -147,10 +150,26 @@ static void event_handler(void* arg, esp_event_base_t event_base,
                          "\n\tPlease reset to factory and retry provisioning",
                          (*reason == WIFI_PROV_STA_AUTH_ERROR) ?
                          "Wi-Fi station authentication failed" : "Wi-Fi access-point not found");
+#ifdef CONFIG_APP_WIFI_RESET_PROV_ON_FAILURE
+                retries++;
+                if (retries >= CONFIG_APP_WIFI_PROV_MAX_RETRY_CNT) {
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 3, 1)
+                    ESP_LOGI(TAG, "Failed to connect with provisioned AP, reseting provisioned credentials");
+                    wifi_prov_mgr_reset_sm_state_on_failure();
+                    esp_event_post(APP_WIFI_EVENT, APP_WIFI_EVENT_PROV_RESTART, NULL, 0, portMAX_DELAY);
+#else
+                    ESP_LOGW(TAG, "Failed to connect with provisioned AP, please reset to provisioning manually");
+#endif
+                    retries = 0;
+                }
+#endif
                 break;
             }
             case WIFI_PROV_CRED_SUCCESS:
                 ESP_LOGI(TAG, "Provisioning successful");
+#ifdef CONFIG_APP_WIFI_RESET_PROV_ON_FAILURE
+                retries = 0;
+#endif
                 break;
             case WIFI_PROV_END:
                 if (prov_stop_timer) {

examples/common/app_wifi/app_wifi.h

@@ -18,6 +18,8 @@ typedef enum {
     APP_WIFI_EVENT_QR_DISPLAY = 1,
     /** Provisioning timed out */
     APP_WIFI_EVENT_PROV_TIMEOUT,
+    /** Provisioning has restarted due to failures (Invalid SSID/Passphrase) */
+    APP_WIFI_EVENT_PROV_RESTART,
 } app_wifi_event_t;
 
 /** Types of Proof of Possession */