2025-01-14 14:47:41 +08:00

288 lines
9.7 KiB
JavaScript

/*******************************************************************************
uBlock Origin - a comprehensive, efficient content blocker
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
*/
import { registerScriptlet } from './base.js';
import { runAt } from './run-at.js';
import { safeSelf } from './safe-self.js';
/******************************************************************************/
export function validateConstantFn(trusted, raw, extraArgs = {}) {
const safe = safeSelf();
let value;
if ( raw === 'undefined' ) {
value = undefined;
} else if ( raw === 'false' ) {
value = false;
} else if ( raw === 'true' ) {
value = true;
} else if ( raw === 'null' ) {
value = null;
} else if ( raw === "''" || raw === '' ) {
value = '';
} else if ( raw === '[]' || raw === 'emptyArr' ) {
value = [];
} else if ( raw === '{}' || raw === 'emptyObj' ) {
value = {};
} else if ( raw === 'noopFunc' ) {
value = function(){};
} else if ( raw === 'trueFunc' ) {
value = function(){ return true; };
} else if ( raw === 'falseFunc' ) {
value = function(){ return false; };
} else if ( raw === 'throwFunc' ) {
value = function(){ throw ''; };
} else if ( /^-?\d+$/.test(raw) ) {
value = parseInt(raw);
if ( isNaN(raw) ) { return; }
if ( Math.abs(raw) > 0x7FFF ) { return; }
} else if ( trusted ) {
if ( raw.startsWith('json:') ) {
try { value = safe.JSON_parse(raw.slice(5)); } catch(ex) { return; }
} else if ( raw.startsWith('{') && raw.endsWith('}') ) {
try { value = safe.JSON_parse(raw).value; } catch(ex) { return; }
}
} else {
return;
}
if ( extraArgs.as !== undefined ) {
if ( extraArgs.as === 'function' ) {
return ( ) => value;
} else if ( extraArgs.as === 'callback' ) {
return ( ) => (( ) => value);
} else if ( extraArgs.as === 'resolved' ) {
return Promise.resolve(value);
} else if ( extraArgs.as === 'rejected' ) {
return Promise.reject(value);
}
}
return value;
}
registerScriptlet(validateConstantFn, {
name: 'validate-constant.fn',
dependencies: [
safeSelf,
],
});
/******************************************************************************/
export function setConstantFn(
trusted = false,
chain = '',
rawValue = ''
) {
if ( chain === '' ) { return; }
const safe = safeSelf();
const logPrefix = safe.makeLogPrefix('set-constant', chain, rawValue);
const extraArgs = safe.getExtraArgs(Array.from(arguments), 3);
function setConstant(chain, rawValue) {
const trappedProp = (( ) => {
const pos = chain.lastIndexOf('.');
if ( pos === -1 ) { return chain; }
return chain.slice(pos+1);
})();
const cloakFunc = fn => {
safe.Object_defineProperty(fn, 'name', { value: trappedProp });
return new Proxy(fn, {
defineProperty(target, prop) {
if ( prop !== 'toString' ) {
return Reflect.defineProperty(...arguments);
}
return true;
},
deleteProperty(target, prop) {
if ( prop !== 'toString' ) {
return Reflect.deleteProperty(...arguments);
}
return true;
},
get(target, prop) {
if ( prop === 'toString' ) {
return function() {
return `function ${trappedProp}() { [native code] }`;
}.bind(null);
}
return Reflect.get(...arguments);
},
});
};
if ( trappedProp === '' ) { return; }
const thisScript = document.currentScript;
let normalValue = validateConstantFn(trusted, rawValue, extraArgs);
if ( rawValue === 'noopFunc' || rawValue === 'trueFunc' || rawValue === 'falseFunc' ) {
normalValue = cloakFunc(normalValue);
}
let aborted = false;
const mustAbort = function(v) {
if ( trusted ) { return false; }
if ( aborted ) { return true; }
aborted =
(v !== undefined && v !== null) &&
(normalValue !== undefined && normalValue !== null) &&
(typeof v !== typeof normalValue);
if ( aborted ) {
safe.uboLog(logPrefix, `Aborted because value set to ${v}`);
}
return aborted;
};
// https://github.com/uBlockOrigin/uBlock-issues/issues/156
// Support multiple trappers for the same property.
const trapProp = function(owner, prop, configurable, handler) {
if ( handler.init(configurable ? owner[prop] : normalValue) === false ) { return; }
const odesc = safe.Object_getOwnPropertyDescriptor(owner, prop);
let prevGetter, prevSetter;
if ( odesc instanceof safe.Object ) {
owner[prop] = normalValue;
if ( odesc.get instanceof Function ) {
prevGetter = odesc.get;
}
if ( odesc.set instanceof Function ) {
prevSetter = odesc.set;
}
}
try {
safe.Object_defineProperty(owner, prop, {
configurable,
get() {
if ( prevGetter !== undefined ) {
prevGetter();
}
return handler.getter();
},
set(a) {
if ( prevSetter !== undefined ) {
prevSetter(a);
}
handler.setter(a);
}
});
safe.uboLog(logPrefix, 'Trap installed');
} catch(ex) {
safe.uboErr(logPrefix, ex);
}
};
const trapChain = function(owner, chain) {
const pos = chain.indexOf('.');
if ( pos === -1 ) {
trapProp(owner, chain, false, {
v: undefined,
init: function(v) {
if ( mustAbort(v) ) { return false; }
this.v = v;
return true;
},
getter: function() {
if ( document.currentScript === thisScript ) {
return this.v;
}
safe.uboLog(logPrefix, 'Property read');
return normalValue;
},
setter: function(a) {
if ( mustAbort(a) === false ) { return; }
normalValue = a;
}
});
return;
}
const prop = chain.slice(0, pos);
const v = owner[prop];
chain = chain.slice(pos + 1);
if ( v instanceof safe.Object || typeof v === 'object' && v !== null ) {
trapChain(v, chain);
return;
}
trapProp(owner, prop, true, {
v: undefined,
init: function(v) {
this.v = v;
return true;
},
getter: function() {
return this.v;
},
setter: function(a) {
this.v = a;
if ( a instanceof safe.Object ) {
trapChain(a, chain);
}
}
});
};
trapChain(window, chain);
}
runAt(( ) => {
setConstant(chain, rawValue);
}, extraArgs.runAt);
}
registerScriptlet(setConstantFn, {
name: 'set-constant.fn',
dependencies: [
runAt,
safeSelf,
validateConstantFn,
],
});
/******************************************************************************/
export function setConstant(
...args
) {
setConstantFn(false, ...args);
}
registerScriptlet(setConstant, {
name: 'set-constant.js',
aliases: [
'set.js',
],
dependencies: [
setConstantFn,
],
});
/*******************************************************************************
*
* trusted-set-constant.js
*
* Set specified property to any value. This is essentially the same as
* set-constant.js, but with no restriction as to which values can be used.
*
**/
export function trustedSetConstant(
...args
) {
setConstantFn(true, ...args);
}
registerScriptlet(trustedSetConstant, {
name: 'trusted-set-constant.js',
requiresTrust: true,
aliases: [
'trusted-set.js',
],
dependencies: [
setConstantFn,
],
});