diff options
Diffstat (limited to 'background')
| -rw-r--r-- | background/CORS_bypass_server.js | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/background/CORS_bypass_server.js b/background/CORS_bypass_server.js new file mode 100644 index 0000000..cbed945 --- /dev/null +++ b/background/CORS_bypass_server.js @@ -0,0 +1,90 @@ +/** + * This file is part of Haketilo. + * + * Function: Allow other parts of the extension to bypass CORS by routing their + * request through this background script using one-off messages. + * + * Copyright (C) 2022 Wojtek Kosior <koszko@koszko.org> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * As additional permission under GNU GPL version 3 section 7, you + * may distribute forms of that code without the copy of the GNU + * GPL normally required by section 4, provided you include this + * license notice and, in case of non-source distribution, a URL + * through which recipients can access the Corresponding Source. + * If you modify file(s) with this exception, you may extend this + * exception to your version of the file(s), but you are not + * obligated to do so. If you do not wish to do so, delete this + * exception statement from your version. + * + * As a special exception to the GPL, any HTML file which merely + * makes function calls to this code, and for that purpose + * includes it by reference shall be deemed a separate work for + * copyright law purposes. If you modify this code, you may extend + * this exception to your version of the code, but you are not + * obligated to do so. If you do not wish to do so, delete this + * exception statement from your version. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + * + * I, Wojtek Kosior, thereby promise not to sue for violation of this file's + * license. Although I request that you do not make use of this code in a + * proprietary program, I am not going to enforce this in court. + */ + +#FROM common/browser.js IMPORT browser + +async function get_prop(object, prop, result_object, call_prop=false) { + try { + result_object[prop] = call_prop ? (await object[prop]()) : object[prop]; + } catch(e) { + result_object[`error-${prop}`] = "" + e; + } +} + +async function perform_download(fetch_data, respond_cb) { + try { + const response = await fetch(fetch_data.url); + const result = {}; + + for (const prop of (fetch_data.to_get || [])) + get_prop(response, prop, result); + + const to_call = (fetch_data.to_call || []); + const promises = []; + for (let i = 0; i < to_call.length; i++) { + const response_to_use = i === to_call.length - 1 ? + response : response.clone(); + promises.push(get_prop(response_to_use, to_call[i], result, true)); + } + + await Promise.all(promises); + return result; + } catch(e) { + return {error: "" + e}; + } +} + +function on_CORS_bypass_request([type, fetch_data], sender, respond_cb) { + if (type !== "CORS_bypasss") + return; + + perform_download(fetch_data).then(respond_cb); + + return true; +} + +function start() { + browser.runtime.onMessage.addListener(on_CORS_bypass_request); +} +#EXPORT start |