ematrix/js/contentscript.js

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

    ηMatrix - a browser extension to black/white list requests.
    Copyright (C) 2014-2019 Raymond Hill
    Copyright (C) 2019 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://libregit.org/heckyel/ematrix
    uMatrix Home: https://github.com/gorhill/uMatrix
*/

/* global HTMLDocument, XMLDocument */

'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() {
        var 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 {
            var hasLocalStorage =
                window.localStorage && window.localStorage.length !== 0;
            var 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

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

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

            var 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;
            }

            var placeholders = response.placeholders,
                tag, prop, src, collapsed, docurl, replaced;

            for ( var target of targets ) {
                tag = target.localName;
                prop = src1stProps[tag];
                if ( prop === undefined ) { continue; }
                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; }
                }
                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; }
                    docurl =
                        'data:text/html,' +
                        encodeURIComponent(
                            placeholders.frameDocument.replace(
                                reURLPlaceholder,
                                src
                            )
                        );
                    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;
                }
            }
        };

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

        var 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);
            }
        };

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

        var addMany = function(targets) {
            var i = targets.length;
            while ( i-- ) {
                toProcess.push(targets[i]);
            }
        };

        var iframeSourceModified = function(mutations) {
            var i = mutations.length;
            while ( i-- ) {
                addIFrame(mutations[i].target, true);
            }
            process();
        };
        var iframeSourceObserver;
        var iframeSourceObserverOptions = {
            attributes: true,
            attributeFilter: [ 'src' ]
        };

        var 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);
            }
            var src = iframe.src;
            if ( src === '' || typeof src !== 'string' ) { return; }
            if ( src.startsWith('http') === false ) { return; }
            toFilter.push({ type: 'frame', url: iframe.src });
            add(iframe);
        };

        var addIFrames = function(iframes) {
            var i = iframes.length;
            while ( i-- ) {
                addIFrame(iframes[i]);
            }
        };

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

        var 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; }

        var addedNodeLists = [];
        var addedNodeListsTimer;

        var treeMutationObservedHandler = function() {
            addedNodeListsTimer = undefined;
            var i = addedNodeLists.length;
            while ( 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.
        var treeMutationObservedHandlerAsync = function(mutations) {
            var iMutation = mutations.length,
                nodeList;
            while ( iMutation-- ) {
                nodeList = mutations[iMutation].addedNodes;
                if ( nodeList.length !== 0 ) {
                    addedNodeLists.push(nodeList);
                }
            }
            if ( addedNodeListsTimer === undefined ) {
                addedNodeListsTimer = vAPI.setTimeout(treeMutationObservedHandler, 47);
            }
        };

        // https://github.com/gorhill/httpswitchboard/issues/176
        var 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() {
        var noscripts = document.querySelectorAll('noscript');
        if ( noscripts.length === 0 ) { return; }

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

        var autoRefresh = function(root) {
            var meta = root.querySelector('meta[http-equiv="refresh"][content]');
            if ( meta === null ) { return; }
            var match = reMetaContent.exec(meta.getAttribute('content'));
            if ( match === null || match[3].trim() === '' ) { return; }
            var 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);
        };

        var morphNoscript = function(from) {
            if ( /^application\/(?:xhtml\+)?xml/.test(document.contentType) ) {
                var to = document.createElement('span');
                while ( from.firstChild !== null ) {
                    to.appendChild(from.firstChild);
                }
                return to;
            }
            var parser = new DOMParser();
            var doc = parser.parseFromString(
                '<span>' + from.textContent + '</span>',
                'text/html'
            );
            return document.adoptNode(doc.querySelector('span'));
        };

        var renderNoscriptTags = function(response) {
            if ( response !== true ) { return; }
            var parent, span;
            for ( var noscript of noscripts ) {
                parent = noscript.parentNode;
                if ( parent === null ) { continue; }
                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();
            }
        }
    );

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

})();