ematrix/js/contentscript.js

/*******************************************************************************

    ηMatrix - a browser extension to black/white list requests.
    Copyright (C) 2014-2019 Raymond Hill
    Copyright (C) 2019-2022 Alessio Vanni

    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://gitlab.com/vannilla/ematrix
    uMatrix Home: https://github.com/gorhill/uMatrix
*/

'use strict';

// Injected into content pages

(function () {
    // https://github.com/chrisaljoudi/uBlock/issues/464
    // https://github.com/gorhill/uMatrix/issues/621
    if (document instanceof HTMLDocument === false
	&& document instanceof XMLDocument === false) {
	return;
    }

    // This can also happen (for example if script injected into a
    // `data:` URI doc)
    if (!window.location) {
	return;
    }

    // This can happen
    if (typeof vAPI !== 'object') {
	//console.debug('contentscript.js > vAPI not found');
	return;
    }

    // https://github.com/chrisaljoudi/uBlock/issues/456
    // Already injected?
    if (vAPI.contentscriptEndInjected) {
	//console.debug('contentscript.js > content script already injected');
	return;
    }
    vAPI.contentscriptEndInjected = true;

    // Executed only once.
    (function () {
	let localStorageHandler = function (mustRemove) {
            if (mustRemove) {
		window.localStorage.clear();
		window.sessionStorage.clear();
            }
	};

	// Check with extension whether local storage must be emptied
	// rhill 2014-03-28: we need an exception handler in case
	// 3rd-party access to site data is disabled.
	// https://github.com/gorhill/httpswitchboard/issues/215
	try {
            let hasLocalStorage =
		window.localStorage && window.localStorage.length !== 0;
            let hasSessionStorage =
		window.sessionStorage && window.sessionStorage.length !== 0;

            if (hasLocalStorage || hasSessionStorage) {
		vAPI.messaging.send('contentscript.js', {
                    what: 'contentScriptHasLocalStorage',
                    originURL: window.location.origin
		}, localStorageHandler);
            }

            // TODO: indexedDB
            //if ( window.indexedDB && !!window.indexedDB.webkitGetDatabaseNames ) {
            // var db = window.indexedDB.webkitGetDatabaseNames().onsuccess = function(sender) {
            //    console.debug('webkitGetDatabaseNames(): result=%o', sender.target.result);
            // };
            //}

            // TODO: Web SQL
            // if ( window.openDatabase ) {
            // Sad:
            // "There is no way to enumerate or delete the databases available for an origin from this API."
            // Ref.: http://www.w3.org/TR/webdatabase/#databases
            // }
	} catch (e) {
	}
    })();

    // https://github.com/gorhill/uMatrix/issues/45
    let collapser = (function () {
	let resquestIdGenerator = 1;
        let processTimer;
        let toProcess = [];
        let toFilter = [];
        let toCollapse = new Map();
        let cachedBlockedMap;
        let cachedBlockedMapHash;
        let cachedBlockedMapTimer;
        let reURLPlaceholder = /\{\{url\}\}/g;
	let src1stProps = {
            embed: 'src',
            iframe: 'src',
            img: 'src',
            object: 'data',
	};
	let src2ndProps = {
            img: 'srcset',
	};
	let tagToTypeMap = {
            embed: 'media',
            iframe: 'frame',
            img: 'image',
            object: 'media',
	};
	let cachedBlockedSetClear = function () {
            cachedBlockedMap =
		cachedBlockedMapHash =
		cachedBlockedMapTimer = undefined;
	};

	// https://github.com/chrisaljoudi/uBlock/issues/174
	// Do not remove fragment from src URL
	let onProcessed = function (response) {
            if (!response) { // This happens if uBO is disabled or restarted.
		toCollapse.clear();
		return;
            }

            let targets = toCollapse.get(response.id);
            if (targets === undefined) {
		return;
	    }

            toCollapse.delete(response.id);

            if (cachedBlockedMapHash !== response.hash) {
		cachedBlockedMap = new Map(response.blockedResources);
		cachedBlockedMapHash = response.hash;
		if (cachedBlockedMapTimer !== undefined) {
                    clearTimeout(cachedBlockedMapTimer);
		}
		cachedBlockedMapTimer =
		    vAPI.setTimeout(cachedBlockedSetClear, 30000);
            }

            if (cachedBlockedMap === undefined || cachedBlockedMap.size === 0) {
		return;
            }

            let placeholders = response.placeholders;

            for (let target of targets) {
		let tag = target.localName;

		let prop = src1stProps[tag];
		if (prop === undefined) {
		    continue;
		}

		let src = target[prop];
		if (typeof src !== 'string' || src.length === 0) {
                    prop = src2ndProps[tag];
                    if (prop === undefined) {
			continue;
		    }
                    src = target[prop];
                    if (typeof src !== 'string' || src.length === 0) {
			continue;
		    }
		}

		let collapsed = cachedBlockedMap.get(tagToTypeMap[tag]
						     + ' '
						     + src);
		if (collapsed === undefined) {
		    continue;
		}

		if (collapsed) {
                    target.style.setProperty('display', 'none', 'important');
                    target.hidden = true;
                    continue;
		}

		switch (tag) {
		case 'iframe':
                    if (placeholders.frame !== true) {
			break;
		    }

                    let docurl = 'data:text/html,'
			+ encodeURIComponent(placeholders
					     .frameDocument
					     .replace(reURLPlaceholder, src));
                    let replaced = false;

                    // Using contentWindow.location prevent tainting browser
                    // history -- i.e. breaking back button (seen on Chromium).
                    if (target.contentWindow) {
			try {
                            target.contentWindow.location.replace(docurl);
                            replaced = true;
			} catch(ex) {
			}
                    }

                    if (!replaced) {
			target.setAttribute('src', docurl);
                    }
                    break;
		case 'img':
                    if (placeholders.image !== true) {
			break;
		    }

                    target.style.setProperty('display', 'inline-block');
                    target.style.setProperty('min-width', '20px', 'important');
                    target.style.setProperty('min-height', '20px', 'important');
                    target.style.setProperty('border', placeholders.imageBorder,
					     'important');
                    target.style.setProperty('background',
					     placeholders.imageBackground,
					     'important');
                    break;
		}
            }
	};

	let send = function () {
            processTimer = undefined;
            toCollapse.set(resquestIdGenerator, toProcess);
            let msg = {
		what: 'lookupBlockedCollapsibles',
		id: resquestIdGenerator,
		toFilter: toFilter,
		hash: cachedBlockedMapHash
            };
            vAPI.messaging.send('contentscript.js', msg, onProcessed);
            toProcess = [];
            toFilter = [];
            resquestIdGenerator += 1;
	};

	let process = function (delay) {
            if (toProcess.length === 0) {
		return;
	    }

            if (delay === 0) {
		if (processTimer !== undefined) {
                    clearTimeout(processTimer);
		}
		send();
            } else if (processTimer === undefined) {
		processTimer = vAPI.setTimeout(send, delay || 47);
            }
	};

	let add = function (target) {
            toProcess.push(target);
	};

	let addMany = function (targets) {
	    for (let i=targets.length-1; i>=0; --i) {
		toProcess.push(targets[i]);
            }
	};

	let iframeSourceModified = function (mutations) {
	    for (let i=mutations.length-1; i>=0; --i) {
		addIFrame(mutations[i].target, true);
            }
            process();
	};

	let iframeSourceObserver;
	let iframeSourceObserverOptions = {
            attributes: true,
            attributeFilter: [ 'src' ]
	};

	let addIFrame = function (iframe, dontObserve) {
            // https://github.com/gorhill/uBlock/issues/162
            // Be prepared to deal with possible change of src attribute.
            if (dontObserve !== true) {
		if (iframeSourceObserver === undefined) {
                    iframeSourceObserver =
			new MutationObserver(iframeSourceModified);
		}
		iframeSourceObserver.observe(iframe,
					     iframeSourceObserverOptions);
            }

            let src = iframe.src;
            if (src === '' || typeof src !== 'string') {
		return;
	    }
            if (src.startsWith('http') === false) {
		return;
	    }

            toFilter.push({
		type: 'frame',
		url: iframe.src,
	    });

            add(iframe);
	};

	let addIFrames = function (iframes) {
	    for (let i=iframes.length-1; i>=0; --i) {
		addIFrame(iframes[i]);
            }
	};

	let addNodeList = function (nodeList) {
	    for (let i=nodeList.length-1; i>=0; --i) {
		let node = nodeList[i];
		if (node.nodeType !== 1) {
		    continue;
		}
		if (node.localName === 'iframe') {
                    addIFrame(node);
		}
		if (node.childElementCount !== 0) {
                    addIFrames(node.querySelectorAll('iframe'));
		}
            }
	};

	let onResourceFailed = function (ev) {
            if (tagToTypeMap[ev.target.localName] !== undefined) {
		add(ev.target);
		process();
            }
	};
	document.addEventListener('error', onResourceFailed, true);

	vAPI.shutdown.add(function () {
            document.removeEventListener('error', onResourceFailed, true);
            if (iframeSourceObserver !== undefined) {
		iframeSourceObserver.disconnect();
		iframeSourceObserver = undefined;
            }
            if (processTimer !== undefined) {
		clearTimeout(processTimer);
		processTimer = undefined;
            }
	});

	return {
            addMany: addMany,
            addIFrames: addIFrames,
            addNodeList: addNodeList,
            process: process
	};
    })();

    // Observe changes in the DOM
    // Added node lists will be cumulated here before being processed

    (function () {
	// This fixes http://acid3.acidtests.org/
	if (!document.body) {
	    return;
	}

	let addedNodeLists = [];
	let addedNodeListsTimer;

	let treeMutationObservedHandler = function () {
            addedNodeListsTimer = undefined;
	    for (let i=addedNodeLists.length-1; i>=0; --i) {
		collapser.addNodeList(addedNodeLists[i]);
            }
            collapser.process();
            addedNodeLists = [];
	};

	// https://github.com/gorhill/uBlock/issues/205
	// Do not handle added node directly from within mutation observer.
	let treeMutationObservedHandlerAsync = function (mutations) {
	    for (let i=mutations.length-1; i>=0; --i) {
		let nodeList = mutations[i].addedNodes;
		if (nodeList.length !== 0) {
                    addedNodeLists.push(nodeList);
		}
            }
            if (addedNodeListsTimer === undefined) {
		addedNodeListsTimer =
		    vAPI.setTimeout(treeMutationObservedHandler, 47);
            }
	};

	// https://github.com/gorhill/httpswitchboard/issues/176
	let treeObserver =
	    new MutationObserver(treeMutationObservedHandlerAsync);
	treeObserver.observe(document.body, {
            childList: true,
            subtree: true
	});

	vAPI.shutdown.add(function () {
            if (addedNodeListsTimer !== undefined) {
		clearTimeout(addedNodeListsTimer);
		addedNodeListsTimer = undefined;
            }
            if (treeObserver !== null) {
		treeObserver.disconnect();
		treeObserver = undefined;
            }
            addedNodeLists = [];
	});
    })();

    // Executed only once.
    //
    // https://github.com/gorhill/httpswitchboard/issues/25
    //
    // https://github.com/gorhill/httpswitchboard/issues/131
    //   Looks for inline javascript also in at least one a[href] element.
    //
    // https://github.com/gorhill/uMatrix/issues/485
    //   Mind "on..." attributes.
    //
    // https://github.com/gorhill/uMatrix/issues/924
    //   Report inline styles.

    (function () {
	if (document.querySelector('script:not([src])') !== null
	    || document.querySelector('a[href^="javascript:"]') !== null
	    || document.querySelector('[onabort],[onblur],[oncancel],'
				      + '[oncanplay],[oncanplaythrough],'
				      + '[onchange],[onclick],[onclose],'
				      + '[oncontextmenu],[oncuechange],'
				      + '[ondblclick],[ondrag],[ondragend],'
				      + '[ondragenter],[ondragexit],'
				      + '[ondragleave],[ondragover],'
				      + '[ondragstart],[ondrop],'
				      + '[ondurationchange],[onemptied],'
				      + '[onended],[onerror],[onfocus],'
				      + '[oninput],[oninvalid],[onkeydown],'
				      + '[onkeypress],[onkeyup],[onload],'
				      + '[onloadeddata],[onloadedmetadata],'
				      + '[onloadstart],[onmousedown],'
				      + '[onmouseenter],[onmouseleave],'
				      + '[onmousemove],[onmouseout],'
				      + '[onmouseover],[onmouseup],[onwheel],'
				      + '[onpause],[onplay],[onplaying],'
				      + '[onprogress],[onratechange],[onreset],'
				      + '[onresize],[onscroll],[onseeked],'
				      + '[onseeking],[onselect],[onshow],'
				      + '[onstalled],[onsubmit],[onsuspend],'
				      + '[ontimeupdate],[ontoggle],'
				      + '[onvolumechange],[onwaiting],'
				      + '[onafterprint],[onbeforeprint],'
				      + '[onbeforeunload],[onhashchange],'
				      + '[onlanguagechange],[onmessage],'
				      + '[onoffline],[ononline],[onpagehide],'
				      + '[onpageshow],[onrejectionhandled],'
				      + '[onpopstate],[onstorage],'
				      + '[onunhandledrejection],[onunload],'
				      + '[oncopy],[oncut],[onpaste]') !== null) {
            vAPI.messaging.send('contentscript.js', {
		what: 'securityPolicyViolation',
		directive: 'script-src',
		documentURI: window.location.href
            });
	}

	if (document.querySelector('style,[style]') !== null) {
            vAPI.messaging.send('contentscript.js', {
		what: 'securityPolicyViolation',
		directive: 'style-src',
		documentURI: window.location.href
            });
	}

	collapser.addMany(document.querySelectorAll('img'));
	collapser.addIFrames(document.querySelectorAll('iframe'));
	collapser.process();
    })();

    // Executed only once.
    // https://github.com/gorhill/uMatrix/issues/232
    // Force `display` property, Firefox is still affected by the issue.

    (function () {
	let noscripts = document.querySelectorAll('noscript');
	if (noscripts.length === 0) {
	    return;
	}

	let redirectTimer;
        let reMetaContent = /^\s*(\d+)\s*;\s*url=(['"]?)([^'"]+)\2/i;
        let reSafeURL = /^https?:\/\//;

	let autoRefresh = function (root) {
            let meta =
		root.querySelector('meta[http-equiv="refresh"][content]');
            if (meta === null) {
		return;
	    }

            let match = reMetaContent.exec(meta.getAttribute('content'));
            if (match === null || match[3].trim() === '') {
		return;
	    }

            let url = new URL(match[3], document.baseURI);
            if (reSafeURL.test(url.href) === false) {
		return;
	    }

            redirectTimer = setTimeout(function () {
                location.assign(url.href);
	    }, parseInt(match[1], 10) * 1000 + 1);

            meta.parentNode.removeChild(meta);
	};

	let morphNoscript = function (from) {
            if (/^application\/(?:xhtml\+)?xml/.test(document.contentType)) {
		let to = document.createElement('span');
		while (from.firstChild !== null) {
                    to.appendChild(from.firstChild);
		}
		return to;
            }

            let parser = new DOMParser();
            let doc =
		parser.parseFromString('<span>' + from.textContent + '</span>',
				       'text/html');

            return document.adoptNode(doc.querySelector('span'));
	};

	let renderNoscriptTags = function (response) {
            if (response !== true) {
		return;
	    }

            for (let noscript of noscripts) {
		let parent = noscript.parentNode;
		if (parent === null) {
		    continue;
		}

		let span = morphNoscript(noscript);
		span.style.setProperty('display', 'inline', 'important');

		if (redirectTimer === undefined) {
                    autoRefresh(span);
		}

		parent.replaceChild(span, noscript);
            }
	};

	vAPI.messaging.send('contentscript.js', {
	    what: 'mustRenderNoscriptTags?'
	}, renderNoscriptTags);
    })();

    vAPI.messaging.send('contentscript.js', {
	what: 'shutdown?'
    }, function (response) {
        if (response === true) {
	    vAPI.shutdown.exec();
        }
    });
})();