ota: Minor improvements

- Expose some internal APIs
    - External OTA callbacks can now call the internal function to manage OTA
    - Applications can explicitly send the OTA fetch publish message to check
    if OTA is available in case of OTA using Topics

- Handle network connectivity loss using keep-alive

- Send "rejected" as OTA status for project/version mismatch, instead of
  "failed".

components/esp_rainmaker/include/esp_rmaker_ota.h

@@ -34,6 +34,8 @@ typedef enum {
     OTA_STATUS_FAILED,
     /** OTA was delayed by the application */
     OTA_STATUS_DELAYED,
+    /** OTA rejected due to some reason (wrong project, version, etc.) */
+    OTA_STATUS_REJECTED,
 } ota_status_t;
 
 /** OTA Workflow type */
@@ -145,6 +147,29 @@ esp_err_t esp_rmaker_ota_enable(esp_rmaker_ota_config_t *ota_config, esp_rmaker_
  */
 esp_err_t esp_rmaker_ota_report_status(esp_rmaker_ota_handle_t ota_handle, ota_status_t status, char *additional_info);
 
+/** Default OTA callback
+ *
+ * This is the default OTA callback which will get used if you do not pass your own callback. You can call this
+ * even from your callback, in case you want better control on when the OTA can proceed and yet let the actual
+ * OTA process be managed by the RainMaker Core.
+ *
+ * @param[in] handle An OTA handle assigned by the ESP RainMaker Core
+ * @param[in] ota_data The data to be used for the OTA
+ *
+ * @return ESP_OK if the OTA was successful
+ * @return ESP_FAIL if the OTA failed.
+ * */
+esp_err_t esp_rmaker_ota_default_cb(esp_rmaker_ota_handle_t handle, esp_rmaker_ota_data_t *ota_data);
+
+/** Fetch OTA Info
+ *
+ * For OTA using Topics, this API can be used to explicitly ask the backend if an OTA is available.
+ * If it is, then the OTA callback would get invoked.
+ *
+ * @return ESP_OK if the OTA fetch publish message was successful.
+ * @return error on failure
+ */
+esp_err_t esp_rmaker_ota_fetch(void);
 #ifdef __cplusplus
 }
 #endif

components/esp_rainmaker/src/ota/esp_rmaker_ota.c

@@ -47,6 +47,8 @@ char *esp_rmaker_ota_status_to_string(ota_status_t status)
             return "failed";
         case OTA_STATUS_DELAYED:
             return "delayed";
+        case OTA_STATUS_REJECTED:
+            return "rejected";
         default:
             return "invalid";
     }
@@ -108,27 +110,28 @@ static esp_err_t validate_image_header(esp_rmaker_ota_handle_t ota_handle,
         ESP_LOGD(TAG, "Running firmware version: %s", running_app_info.version);
     }
 
-#ifndef CONFIG_ESP_RMAKER_SKIP_VERSION_CHECK
-    if (memcmp(new_app_info->version, running_app_info.version, sizeof(new_app_info->version)) == 0) {
-        ESP_LOGW(TAG, "Current running version is same as the new. We will not continue the update.");
-        esp_rmaker_ota_report_status(ota_handle, OTA_STATUS_FAILED, "Same version received");
-        return ESP_FAIL;
-    }
-#endif
-
 #ifndef CONFIG_ESP_RMAKER_SKIP_PROJECT_NAME_CHECK
     if (memcmp(new_app_info->project_name, running_app_info.project_name, sizeof(new_app_info->project_name)) != 0) {
         ESP_LOGW(TAG, "OTA Image built for Project: %s. Expected: %s",
                 new_app_info->project_name, running_app_info.project_name);
-        esp_rmaker_ota_report_status(ota_handle, OTA_STATUS_FAILED, "Project Name mismatch");
+        esp_rmaker_ota_report_status(ota_handle, OTA_STATUS_REJECTED, "Project Name mismatch");
         return ESP_FAIL;
     }
 #endif
 
+#ifndef CONFIG_ESP_RMAKER_SKIP_VERSION_CHECK
+    if (memcmp(new_app_info->version, running_app_info.version, sizeof(new_app_info->version)) == 0) {
+        ESP_LOGW(TAG, "Current running version is same as the new. We will not continue the update.");
+        esp_rmaker_ota_report_status(ota_handle, OTA_STATUS_REJECTED, "Same version received");
+        return ESP_FAIL;
+    }
+#endif
+
+
     return ESP_OK;
 }
 
-static esp_err_t esp_rmaker_ota_default_cb(esp_rmaker_ota_handle_t ota_handle, esp_rmaker_ota_data_t *ota_data)
+esp_err_t esp_rmaker_ota_default_cb(esp_rmaker_ota_handle_t ota_handle, esp_rmaker_ota_data_t *ota_data)
 {
     if (!ota_data->url) {
         return ESP_FAIL;
@@ -146,7 +149,8 @@ static esp_err_t esp_rmaker_ota_default_cb(esp_rmaker_ota_handle_t ota_handle, e
         .cert_pem = ota_data->server_cert,
         .timeout_ms = 5000,
         .buffer_size = DEF_HTTP_RX_BUFFER_SIZE,
-        .buffer_size_tx = buffer_size_tx
+        .buffer_size_tx = buffer_size_tx,
+        .keep_alive_enable = true
     };
 #ifdef CONFIG_ESP_RMAKER_SKIP_COMMON_NAME_CHECK
     config.skip_cert_common_name_check = true;
@@ -220,6 +224,7 @@ static esp_err_t esp_rmaker_ota_default_cb(esp_rmaker_ota_handle_t ota_handle, e
         }
     }
     if (err != ESP_OK) {
+        ESP_LOGE(TAG, "ESP_HTTPS_OTA upgrade failed %s", esp_err_to_name(err));
         char description[40];
         snprintf(description, sizeof(description), "OTA failed: Error %s", esp_err_to_name(err));
         esp_rmaker_ota_report_status(ota_handle, OTA_STATUS_FAILED, description);

components/esp_rainmaker/src/ota/esp_rmaker_ota_using_topics.c

@@ -169,13 +169,12 @@ end:
     return;
 }
 
-#ifdef CONFIG_ESP_RMAKER_OTA_AUTOFETCH
-static void esp_rmaker_ota_fetch(void *priv)
+esp_err_t esp_rmaker_ota_fetch(void)
 {
     esp_rmaker_node_info_t *info = esp_rmaker_node_get_info(esp_rmaker_get_node());
     if (!info) {
         ESP_LOGE(TAG, "Node info not found. Cant send otafetch request");
-        return;
+        return ESP_FAIL;
     }
     char publish_payload[150];
     json_gen_str_t jstr;
@@ -192,8 +191,13 @@ static void esp_rmaker_ota_fetch(void *priv)
     if (err != ESP_OK) {
         ESP_LOGE(TAG, "OTA Fetch Publish Error %d", err);
     }
+    return err;
+}
+
+void esp_rmaker_ota_timer_cb_fetch(void *priv)
+{
+    esp_rmaker_ota_fetch();
 }
-#endif /* CONFIG_ESP_RMAKER_OTA_AUTOFETCH */
 
 static esp_err_t esp_rmaker_ota_subscribe(void *priv_data)
 {
@@ -215,10 +219,10 @@ static void esp_rmaker_ota_work_fn(void *priv_data)
 {
     esp_rmaker_ota_subscribe(priv_data);
 #ifdef CONFIG_ESP_RMAKER_OTA_AUTOFETCH
-    esp_rmaker_ota_fetch(priv_data);
+    esp_rmaker_ota_fetch();
     if (ota_autofetch_period > 0) {
         esp_timer_create_args_t autofetch_timer_conf = {
-            .callback = esp_rmaker_ota_fetch,
+            .callback = esp_rmaker_ota_timer_cb_fetch,
             .arg = priv_data,
             .dispatch_method = ESP_TIMER_TASK,
             .name = "ota_autofetch_tm"