Merge branch 'feature/handle_ota_image_not_modified_case' into 'master'

feat(esp_htttps_ota): handle case if server retured 304 not_modified during ota

Closes IDFGH-14016

See merge request espressif/esp-idf!34808

components/esp_common/src/esp_err_to_name.c

@@ -656,6 +656,9 @@ static const esp_err_msg_t esp_err_msg_table[] = {
 #   endif
 #   ifdef      ESP_ERR_HTTP_CONNECTION_CLOSED
     ERR_TBL_IT(ESP_ERR_HTTP_CONNECTION_CLOSED),                 /* 28680 0x7008 Read FIN from peer and the connection closed */
+#   endif
+#   ifdef      ESP_ERR_HTTP_NOT_MODIFIED
+    ERR_TBL_IT(ESP_ERR_HTTP_NOT_MODIFIED),                      /* 28681 0x7009 HTTP 304 Not Modified, no update available */
 #   endif
     // components/esp-tls/esp_tls_errors.h
 #   ifdef      ESP_ERR_ESP_TLS_BASE

components/esp_http_client/include/esp_http_client.h

@@ -208,6 +208,7 @@ typedef enum {
     HttpStatus_MovedPermanently  = 301,
     HttpStatus_Found             = 302,
     HttpStatus_SeeOther          = 303,
+    HttpStatus_NotModified       = 304,
     HttpStatus_TemporaryRedirect = 307,
     HttpStatus_PermanentRedirect = 308,
 
@@ -230,6 +231,7 @@ typedef enum {
 #define ESP_ERR_HTTP_CONNECTING         (ESP_ERR_HTTP_BASE + 6)     /*!< HTTP connection hasn't been established yet */
 #define ESP_ERR_HTTP_EAGAIN             (ESP_ERR_HTTP_BASE + 7)     /*!< Mapping of errno EAGAIN to esp_err_t */
 #define ESP_ERR_HTTP_CONNECTION_CLOSED  (ESP_ERR_HTTP_BASE + 8)     /*!< Read FIN from peer and the connection closed */
+#define ESP_ERR_HTTP_NOT_MODIFIED       (ESP_ERR_HTTP_BASE + 9)     /*!< HTTP 304 Not Modified, no update available */
 
 /**
  * @brief      Start a HTTP session

components/esp_https_ota/include/esp_https_ota.h

@@ -103,6 +103,7 @@ typedef struct {
  *    - ESP_ERR_OTA_VALIDATE_FAILED: Invalid app image
  *    - ESP_ERR_NO_MEM: Cannot allocate memory for OTA operation.
  *    - ESP_ERR_FLASH_OP_TIMEOUT or ESP_ERR_FLASH_OP_FAIL: Flash write failed.
+ *    - ESP_ERR_HTTP_NOT_MODIFIED: OTA image is not modified on server side
  *    - For other return codes, refer OTA documentation in esp-idf's app_update component.
  */
 esp_err_t esp_https_ota(const esp_https_ota_config_t *ota_config);
@@ -129,6 +130,7 @@ esp_err_t esp_https_ota(const esp_https_ota_config_t *ota_config);
  *    - ESP_OK: HTTPS OTA Firmware upgrade context initialised and HTTPS connection established
  *    - ESP_FAIL: For generic failure.
  *    - ESP_ERR_INVALID_ARG: Invalid argument (missing/incorrect config, certificate, etc.)
+ *    - ESP_ERR_HTTP_NOT_MODIFIED: OTA image is not modified on server side
  *    - For other return codes, refer documentation in app_update component and esp_http_client
  *      component in esp-idf.
  */

components/esp_https_ota/src/esp_https_ota.c

@@ -97,12 +97,16 @@ static bool process_again(int status_code)
 static esp_err_t _http_handle_response_code(esp_https_ota_t *https_ota_handle, int status_code)
 {
     esp_err_t err;
+
     if (redirection_required(status_code)) {
         err = esp_http_client_set_redirection(https_ota_handle->http_client);
         if (err != ESP_OK) {
             ESP_LOGE(TAG, "URL redirection Failed");
             return err;
         }
+    } else if (status_code == HttpStatus_NotModified) {
+        ESP_LOGI(TAG, "OTA image not modified since last request (status code: %d)", status_code);
+        return ESP_ERR_HTTP_NOT_MODIFIED;
     } else if (status_code == HttpStatus_Unauthorized) {
         if (https_ota_handle->max_authorization_retries == 0) {
             ESP_LOGE(TAG, "Reached max_authorization_retries (%d)", status_code);
@@ -357,7 +361,9 @@ esp_err_t esp_https_ota_begin(const esp_https_ota_config_t *ota_config, esp_http
 
     err = _http_connect(https_ota_handle);
     if (err != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to establish HTTP connection");
+        if (err != ESP_ERR_HTTP_NOT_MODIFIED) {
+            ESP_LOGE(TAG, "Failed to establish HTTP connection");
+        }
         goto http_cleanup;
     } else {
         esp_https_ota_dispatch_event(ESP_HTTPS_OTA_CONNECTED, NULL, 0);
@@ -820,6 +826,10 @@ esp_err_t esp_https_ota(const esp_https_ota_config_t *ota_config)
 
     esp_https_ota_handle_t https_ota_handle = NULL;
     esp_err_t err = esp_https_ota_begin(ota_config, &https_ota_handle);
+    if (err != ESP_OK) {
+        return err;
+    }
+
     if (https_ota_handle == NULL) {
         return ESP_FAIL;
     }