uBlock/platform/mv3/scriptlets/abort-on-property-write.js

120 lines
3.5 KiB
JavaScript

/*******************************************************************************
uBlock Origin - a browser extension to block requests.
Copyright (C) 2019-present Raymond Hill
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.
You should have received a copy of the GNU General Public License
along with this program. If not, see {http://www.gnu.org/licenses/}.
Home: https://github.com/gorhill/uBlock
The scriptlets below are meant to be injected only into a
web page context.
*/
/* jshint esversion:11 */
'use strict';
/******************************************************************************/
/// name abort-on-property-write
/// alias aopw
/******************************************************************************/
// Important!
// Isolate from global scope
(function uBOL_abortOnPropertyWrite() {
/******************************************************************************/
// $rulesetId$
const argsMap = new Map(self.$argsMap$);
const hostnamesMap = new Map(self.$hostnamesMap$);
/******************************************************************************/
const magic =
String.fromCharCode(Date.now() % 26 + 97) +
Math.floor(Math.random() * 982451653 + 982451653).toString(36);
const abort = function() {
throw new ReferenceError(magic);
};
const scriptlet = (
prop = ''
) => {
let owner = window;
for (;;) {
const pos = prop.indexOf('.');
if ( pos === -1 ) { break; }
owner = owner[prop.slice(0, pos)];
if ( owner instanceof Object === false ) { return; }
prop = prop.slice(pos + 1);
}
delete owner[prop];
Object.defineProperty(owner, prop, {
set: function() {
abort();
}
});
const oe = window.onerror;
window.onerror = function(msg, src, line, col, error) {
if ( typeof msg === 'string' && msg.includes(magic) ) {
return true;
}
if ( oe instanceof Function ) {
return oe(msg, src, line, col, error);
}
}.bind();
};
/******************************************************************************/
let hn;
try { hn = document.location.hostname; } catch(ex) { }
while ( hn ) {
if ( hostnamesMap.has(hn) ) {
let argsHashes = hostnamesMap.get(hn);
if ( typeof argsHashes === 'number' ) { argsHashes = [ argsHashes ]; }
for ( const argsHash of argsHashes ) {
const details = argsMap.get(argsHash);
if ( details.n && details.n.includes(hn) ) { continue; }
try { scriptlet(...details.a); } catch(ex) {}
}
}
if ( hn === '*' ) { break; }
const pos = hn.indexOf('.');
if ( pos !== -1 ) {
hn = hn.slice(pos + 1);
} else {
hn = '*';
}
}
/******************************************************************************/
argsMap.clear();
hostnamesMap.clear();
/******************************************************************************/
})();
/******************************************************************************/