Merge branch 'bugfix/send_conn_close_header' into 'master'

file_serving example: Demonstrate use of connection close header from request headers

Closes IDFGH-3874

See merge request espressif/esp-idf!11922

examples/protocols/http_server/file_serving/main/Kconfig.projbuild

@@ -21,4 +21,10 @@ menu "Http_File_Serving Example menu"
             If this config item is set, SDMMC is used to mount the SDcard.
             Otherwise, will use SPI host to access and mount the SDcard.
 
+    config EXAMPLE_HTTPD_CONN_CLOSE_HEADER
+        bool "Send connection close header from request handlers"
+        default y
+        help
+            If this config item is set, Connection: close header will be set in handlers.
+            This closes HTTP connection and frees the server socket instantly.
 endmenu

examples/protocols/http_server/file_serving/main/file_server.c

@@ -277,6 +277,9 @@ static esp_err_t download_get_handler(httpd_req_t *req)
     ESP_LOGI(TAG, "File sending complete");
 
     /* Respond with an empty chunk to signal HTTP response completion */
+#ifdef CONFIG_EXAMPLE_HTTPD_CONN_CLOSE_HEADER
+    httpd_resp_set_hdr(req, "Connection", "close");
+#endif
     httpd_resp_send_chunk(req, NULL, 0);
     return ESP_OK;
 }
@@ -388,6 +391,9 @@ static esp_err_t upload_post_handler(httpd_req_t *req)
     /* Redirect onto root to see the updated file list */
     httpd_resp_set_status(req, "303 See Other");
     httpd_resp_set_hdr(req, "Location", "/");
+#ifdef CONFIG_EXAMPLE_HTTPD_CONN_CLOSE_HEADER
+    httpd_resp_set_hdr(req, "Connection", "close");
+#endif
     httpd_resp_sendstr(req, "File uploaded successfully");
     return ESP_OK;
 }
@@ -429,6 +435,9 @@ static esp_err_t delete_post_handler(httpd_req_t *req)
     /* Redirect onto root to see the updated file list */
     httpd_resp_set_status(req, "303 See Other");
     httpd_resp_set_hdr(req, "Location", "/");
+#ifdef CONFIG_EXAMPLE_HTTPD_CONN_CLOSE_HEADER
+    httpd_resp_set_hdr(req, "Connection", "close");
+#endif
     httpd_resp_sendstr(req, "File deleted successfully");
     return ESP_OK;
 }