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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2001 Dirk Mueller (mueller (at) kde.org)
      5  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
      6  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann (at) kde.org>
      7  *
      8  * This library is free software; you can redistribute it and/or
      9  * modify it under the terms of the GNU Library General Public
     10  * License as published by the Free Software Foundation; either
     11  * version 2 of the License, or (at your option) any later version.
     12  *
     13  * This library is distributed in the hope that it will be useful,
     14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     16  * Library General Public License for more details.
     17  *
     18  * You should have received a copy of the GNU Library General Public License
     19  * along with this library; see the file COPYING.LIB.  If not, write to
     20  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     21  * Boston, MA 02110-1301, USA.
     22  */
     23 
     24 #include "config.h"
     25 #include "core/dom/ScriptLoader.h"
     26 
     27 #include "HTMLNames.h"
     28 #include "SVGNames.h"
     29 #include "bindings/v8/ScriptController.h"
     30 #include "bindings/v8/ScriptSourceCode.h"
     31 #include "core/dom/Document.h"
     32 #include "core/events/Event.h"
     33 #include "core/dom/IgnoreDestructiveWriteCountIncrementer.h"
     34 #include "core/dom/ScriptLoaderClient.h"
     35 #include "core/dom/ScriptRunner.h"
     36 #include "core/dom/ScriptableDocumentParser.h"
     37 #include "core/dom/Text.h"
     38 #include "core/fetch/FetchRequest.h"
     39 #include "core/fetch/ResourceFetcher.h"
     40 #include "core/fetch/ScriptResource.h"
     41 #include "core/html/HTMLImport.h"
     42 #include "core/html/HTMLScriptElement.h"
     43 #include "core/html/parser/HTMLParserIdioms.h"
     44 #include "core/frame/ContentSecurityPolicy.h"
     45 #include "core/frame/Frame.h"
     46 #include "core/svg/SVGScriptElement.h"
     47 #include "platform/MIMETypeRegistry.h"
     48 #include "platform/weborigin/SecurityOrigin.h"
     49 #include "wtf/StdLibExtras.h"
     50 #include "wtf/text/StringBuilder.h"
     51 #include "wtf/text/StringHash.h"
     52 
     53 namespace WebCore {
     54 
     55 ScriptLoader::ScriptLoader(Element* element, bool parserInserted, bool alreadyStarted)
     56     : m_element(element)
     57     , m_resource(0)
     58     , m_startLineNumber(WTF::OrdinalNumber::beforeFirst())
     59     , m_parserInserted(parserInserted)
     60     , m_isExternalScript(false)
     61     , m_alreadyStarted(alreadyStarted)
     62     , m_haveFiredLoad(false)
     63     , m_willBeParserExecuted(false)
     64     , m_readyToBeParserExecuted(false)
     65     , m_willExecuteWhenDocumentFinishedParsing(false)
     66     , m_forceAsync(!parserInserted)
     67     , m_willExecuteInOrder(false)
     68     , m_isPotentiallyCORSEnabled(false)
     69 {
     70     ASSERT(m_element);
     71     if (parserInserted && element->document().scriptableDocumentParser() && !element->document().isInDocumentWrite())
     72         m_startLineNumber = element->document().scriptableDocumentParser()->lineNumber();
     73 }
     74 
     75 ScriptLoader::~ScriptLoader()
     76 {
     77     stopLoadRequest();
     78 }
     79 
     80 void ScriptLoader::didNotifySubtreeInsertionsToDocument()
     81 {
     82     if (!m_parserInserted)
     83         prepareScript(); // FIXME: Provide a real starting line number here.
     84 }
     85 
     86 void ScriptLoader::childrenChanged()
     87 {
     88     if (!m_parserInserted && m_element->inDocument())
     89         prepareScript(); // FIXME: Provide a real starting line number here.
     90 }
     91 
     92 void ScriptLoader::handleSourceAttribute(const String& sourceUrl)
     93 {
     94     if (ignoresLoadRequest() || sourceUrl.isEmpty())
     95         return;
     96 
     97     prepareScript(); // FIXME: Provide a real starting line number here.
     98 }
     99 
    100 void ScriptLoader::handleAsyncAttribute()
    101 {
    102     m_forceAsync = false;
    103 }
    104 
    105 // Helper function
    106 static bool isLegacySupportedJavaScriptLanguage(const String& language)
    107 {
    108     // Mozilla 1.8 accepts javascript1.0 - javascript1.7, but WinIE 7 accepts only javascript1.1 - javascript1.3.
    109     // Mozilla 1.8 and WinIE 7 both accept javascript and livescript.
    110     // WinIE 7 accepts ecmascript and jscript, but Mozilla 1.8 doesn't.
    111     // Neither Mozilla 1.8 nor WinIE 7 accept leading or trailing whitespace.
    112     // We want to accept all the values that either of these browsers accept, but not other values.
    113 
    114     // FIXME: This function is not HTML5 compliant. These belong in the MIME registry as "text/javascript<version>" entries.
    115     typedef HashSet<String, CaseFoldingHash> LanguageSet;
    116     DEFINE_STATIC_LOCAL(LanguageSet, languages, ());
    117     if (languages.isEmpty()) {
    118         languages.add("javascript");
    119         languages.add("javascript");
    120         languages.add("javascript1.0");
    121         languages.add("javascript1.1");
    122         languages.add("javascript1.2");
    123         languages.add("javascript1.3");
    124         languages.add("javascript1.4");
    125         languages.add("javascript1.5");
    126         languages.add("javascript1.6");
    127         languages.add("javascript1.7");
    128         languages.add("livescript");
    129         languages.add("ecmascript");
    130         languages.add("jscript");
    131     }
    132 
    133     return languages.contains(language);
    134 }
    135 
    136 void ScriptLoader::dispatchErrorEvent()
    137 {
    138     m_element->dispatchEvent(Event::create(EventTypeNames::error));
    139 }
    140 
    141 void ScriptLoader::dispatchLoadEvent()
    142 {
    143     if (ScriptLoaderClient* client = this->client())
    144         client->dispatchLoadEvent();
    145     setHaveFiredLoadEvent(true);
    146 }
    147 
    148 bool ScriptLoader::isScriptTypeSupported(LegacyTypeSupport supportLegacyTypes) const
    149 {
    150     // FIXME: isLegacySupportedJavaScriptLanguage() is not valid HTML5. It is used here to maintain backwards compatibility with existing layout tests. The specific violations are:
    151     // - Allowing type=javascript. type= should only support MIME types, such as text/javascript.
    152     // - Allowing a different set of languages for language= and type=. language= supports Javascript 1.1 and 1.4-1.6, but type= does not.
    153 
    154     String type = client()->typeAttributeValue();
    155     String language = client()->languageAttributeValue();
    156     if (type.isEmpty() && language.isEmpty())
    157         return true; // Assume text/javascript.
    158     if (type.isEmpty()) {
    159         type = "text/" + language.lower();
    160         if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type) || isLegacySupportedJavaScriptLanguage(language))
    161             return true;
    162     } else if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type.stripWhiteSpace().lower()) || (supportLegacyTypes == AllowLegacyTypeInTypeAttribute && isLegacySupportedJavaScriptLanguage(type))) {
    163         return true;
    164     }
    165 
    166     return false;
    167 }
    168 
    169 // http://dev.w3.org/html5/spec/Overview.html#prepare-a-script
    170 bool ScriptLoader::prepareScript(const TextPosition& scriptStartPosition, LegacyTypeSupport supportLegacyTypes)
    171 {
    172     if (m_alreadyStarted)
    173         return false;
    174 
    175     ScriptLoaderClient* client = this->client();
    176 
    177     bool wasParserInserted;
    178     if (m_parserInserted) {
    179         wasParserInserted = true;
    180         m_parserInserted = false;
    181     } else {
    182         wasParserInserted = false;
    183     }
    184 
    185     if (wasParserInserted && !client->asyncAttributeValue())
    186         m_forceAsync = true;
    187 
    188     // FIXME: HTML5 spec says we should check that all children are either comments or empty text nodes.
    189     if (!client->hasSourceAttribute() && !m_element->firstChild())
    190         return false;
    191 
    192     if (!m_element->inDocument())
    193         return false;
    194 
    195     if (!isScriptTypeSupported(supportLegacyTypes))
    196         return false;
    197 
    198     if (wasParserInserted) {
    199         m_parserInserted = true;
    200         m_forceAsync = false;
    201     }
    202 
    203     m_alreadyStarted = true;
    204 
    205     // FIXME: If script is parser inserted, verify it's still in the original document.
    206     Document& elementDocument = m_element->document();
    207     Document* contextDocument = elementDocument.contextDocument().get();
    208 
    209     if (!contextDocument || !contextDocument->allowExecutingScripts(m_element))
    210         return false;
    211 
    212     if (!isScriptForEventSupported())
    213         return false;
    214 
    215     if (!client->charsetAttributeValue().isEmpty())
    216         m_characterEncoding = client->charsetAttributeValue();
    217     else
    218         m_characterEncoding = elementDocument.charset();
    219 
    220     if (client->hasSourceAttribute()) {
    221         if (!fetchScript(client->sourceAttributeValue()))
    222             return false;
    223     }
    224 
    225     if (client->hasSourceAttribute() && client->deferAttributeValue() && m_parserInserted && !client->asyncAttributeValue()) {
    226         m_willExecuteWhenDocumentFinishedParsing = true;
    227         m_willBeParserExecuted = true;
    228     } else if (client->hasSourceAttribute() && m_parserInserted && !client->asyncAttributeValue()) {
    229         m_willBeParserExecuted = true;
    230     } else if (!client->hasSourceAttribute() && m_parserInserted && !elementDocument.haveStylesheetsAndImportsLoaded()) {
    231         m_willBeParserExecuted = true;
    232         m_readyToBeParserExecuted = true;
    233     } else if (client->hasSourceAttribute() && !client->asyncAttributeValue() && !m_forceAsync) {
    234         m_willExecuteInOrder = true;
    235         contextDocument->scriptRunner()->queueScriptForExecution(this, m_resource, ScriptRunner::IN_ORDER_EXECUTION);
    236         m_resource->addClient(this);
    237     } else if (client->hasSourceAttribute()) {
    238         contextDocument->scriptRunner()->queueScriptForExecution(this, m_resource, ScriptRunner::ASYNC_EXECUTION);
    239         m_resource->addClient(this);
    240     } else {
    241         // Reset line numbering for nested writes.
    242         TextPosition position = elementDocument.isInDocumentWrite() ? TextPosition() : scriptStartPosition;
    243         KURL scriptURL = (!elementDocument.isInDocumentWrite() && m_parserInserted) ? elementDocument.url() : KURL();
    244         if (!executePotentiallyCrossOriginScript(ScriptSourceCode(scriptContent(), scriptURL, position)))
    245             return false;
    246     }
    247 
    248     return true;
    249 }
    250 
    251 bool ScriptLoader::fetchScript(const String& sourceUrl)
    252 {
    253     ASSERT(m_element);
    254 
    255     RefPtr<Document> elementDocument(m_element->document());
    256     if (!m_element->dispatchBeforeLoadEvent(sourceUrl))
    257         return false;
    258     if (!m_element->inDocument() || m_element->document() != elementDocument)
    259         return false;
    260 
    261     ASSERT(!m_resource);
    262     if (!stripLeadingAndTrailingHTMLSpaces(sourceUrl).isEmpty()) {
    263         FetchRequest request(ResourceRequest(elementDocument->completeURL(sourceUrl)), m_element->localName());
    264 
    265         String crossOriginMode = m_element->fastGetAttribute(HTMLNames::crossoriginAttr);
    266         if (!crossOriginMode.isNull()) {
    267             StoredCredentials allowCredentials = equalIgnoringCase(crossOriginMode, "use-credentials") ? AllowStoredCredentials : DoNotAllowStoredCredentials;
    268             request.setCrossOriginAccessControl(elementDocument->securityOrigin(), allowCredentials);
    269             m_isPotentiallyCORSEnabled = true;
    270         }
    271         request.setCharset(scriptCharset());
    272 
    273         bool isValidScriptNonce = elementDocument->contentSecurityPolicy()->allowScriptNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr));
    274         if (isValidScriptNonce)
    275             request.setContentSecurityCheck(DoNotCheckContentSecurityPolicy);
    276 
    277         m_resource = elementDocument->fetcher()->fetchScript(request);
    278         m_isExternalScript = true;
    279     }
    280 
    281     if (m_resource)
    282         return true;
    283 
    284     dispatchErrorEvent();
    285     return false;
    286 }
    287 
    288 bool isHTMLScriptLoader(Element* element)
    289 {
    290     return element->hasTagName(HTMLNames::scriptTag);
    291 }
    292 
    293 bool isSVGScriptLoader(Element* element)
    294 {
    295     return element->hasTagName(SVGNames::scriptTag);
    296 }
    297 
    298 void ScriptLoader::executeScript(const ScriptSourceCode& sourceCode)
    299 {
    300     ASSERT(m_alreadyStarted);
    301 
    302     if (sourceCode.isEmpty())
    303         return;
    304 
    305     RefPtr<Document> elementDocument(m_element->document());
    306     RefPtr<Document> contextDocument = elementDocument->contextDocument().get();
    307     if (!contextDocument)
    308         return;
    309 
    310     Frame* frame = contextDocument->frame();
    311 
    312     bool shouldBypassMainWorldContentSecurityPolicy = (frame && frame->script().shouldBypassMainWorldContentSecurityPolicy()) || elementDocument->contentSecurityPolicy()->allowScriptNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr)) || elementDocument->contentSecurityPolicy()->allowScriptHash(sourceCode.source());
    313 
    314     if (!m_isExternalScript && (!shouldBypassMainWorldContentSecurityPolicy && !elementDocument->contentSecurityPolicy()->allowInlineScript(elementDocument->url(), m_startLineNumber)))
    315         return;
    316 
    317     if (m_isExternalScript && m_resource && !m_resource->mimeTypeAllowedByNosniff()) {
    318         contextDocument->addConsoleMessage(SecurityMessageSource, ErrorMessageLevel, "Refused to execute script from '" + m_resource->url().elidedString() + "' because its MIME type ('" + m_resource->mimeType() + "') is not executable, and strict MIME type checking is enabled.");
    319         return;
    320     }
    321 
    322     if (frame) {
    323         IgnoreDestructiveWriteCountIncrementer ignoreDesctructiveWriteCountIncrementer(m_isExternalScript ? contextDocument.get() : 0);
    324 
    325         if (isHTMLScriptLoader(m_element))
    326             contextDocument->pushCurrentScript(toHTMLScriptElement(m_element));
    327 
    328         AccessControlStatus corsCheck = NotSharableCrossOrigin;
    329         if (sourceCode.resource() && sourceCode.resource()->passesAccessControlCheck(m_element->document().securityOrigin()))
    330             corsCheck = SharableCrossOrigin;
    331 
    332         // Create a script from the script element node, using the script
    333         // block's source and the script block's type.
    334         // Note: This is where the script is compiled and actually executed.
    335         frame->script().executeScriptInMainWorld(sourceCode, corsCheck);
    336 
    337         if (isHTMLScriptLoader(m_element)) {
    338             ASSERT(contextDocument->currentScript() == m_element);
    339             contextDocument->popCurrentScript();
    340         }
    341     }
    342 }
    343 
    344 void ScriptLoader::stopLoadRequest()
    345 {
    346     if (m_resource) {
    347         if (!m_willBeParserExecuted)
    348             m_resource->removeClient(this);
    349         m_resource = 0;
    350     }
    351 }
    352 
    353 void ScriptLoader::execute(ScriptResource* resource)
    354 {
    355     ASSERT(!m_willBeParserExecuted);
    356     ASSERT(resource);
    357     if (resource->errorOccurred()) {
    358         dispatchErrorEvent();
    359     } else if (!resource->wasCanceled()) {
    360         executeScript(ScriptSourceCode(resource));
    361         dispatchLoadEvent();
    362     }
    363     resource->removeClient(this);
    364 }
    365 
    366 bool ScriptLoader::executePotentiallyCrossOriginScript(const ScriptSourceCode& sourceCode)
    367 {
    368     if (sourceCode.resource()
    369         && isPotentiallyCORSEnabled()
    370         && !m_element->document().fetcher()->canAccess(sourceCode.resource(), PotentiallyCORSEnabled)) {
    371         dispatchErrorEvent();
    372         return false;
    373     }
    374     executeScript(sourceCode);
    375     return true;
    376 }
    377 
    378 void ScriptLoader::notifyFinished(Resource* resource)
    379 {
    380     ASSERT(!m_willBeParserExecuted);
    381 
    382     RefPtr<Document> elementDocument(m_element->document());
    383     RefPtr<Document> contextDocument = elementDocument->contextDocument().get();
    384     if (!contextDocument)
    385         return;
    386 
    387     // Resource possibly invokes this notifyFinished() more than
    388     // once because ScriptLoader doesn't unsubscribe itself from
    389     // Resource here and does it in execute() instead.
    390     // We use m_resource to check if this function is already called.
    391     ASSERT_UNUSED(resource, resource == m_resource);
    392     if (!m_resource)
    393         return;
    394     CORSEnabled corsEnabled = isPotentiallyCORSEnabled() ? PotentiallyCORSEnabled : NotCORSEnabled;
    395     if (!elementDocument->fetcher()->canAccess(m_resource.get(), corsEnabled)) {
    396         dispatchErrorEvent();
    397         contextDocument->scriptRunner()->notifyScriptLoadError(this, m_willExecuteInOrder ? ScriptRunner::IN_ORDER_EXECUTION : ScriptRunner::ASYNC_EXECUTION);
    398         return;
    399     }
    400 
    401     if (m_willExecuteInOrder)
    402         contextDocument->scriptRunner()->notifyScriptReady(this, ScriptRunner::IN_ORDER_EXECUTION);
    403     else
    404         contextDocument->scriptRunner()->notifyScriptReady(this, ScriptRunner::ASYNC_EXECUTION);
    405 
    406     m_resource = 0;
    407 }
    408 
    409 bool ScriptLoader::ignoresLoadRequest() const
    410 {
    411     return m_alreadyStarted || m_isExternalScript || m_parserInserted || !element() || !element()->inDocument();
    412 }
    413 
    414 bool ScriptLoader::isScriptForEventSupported() const
    415 {
    416     String eventAttribute = client()->eventAttributeValue();
    417     String forAttribute = client()->forAttributeValue();
    418     if (!eventAttribute.isEmpty() && !forAttribute.isEmpty()) {
    419         forAttribute = forAttribute.stripWhiteSpace();
    420         if (!equalIgnoringCase(forAttribute, "window"))
    421             return false;
    422 
    423         eventAttribute = eventAttribute.stripWhiteSpace();
    424         if (!equalIgnoringCase(eventAttribute, "onload") && !equalIgnoringCase(eventAttribute, "onload()"))
    425             return false;
    426     }
    427     return true;
    428 }
    429 
    430 String ScriptLoader::scriptContent() const
    431 {
    432     return m_element->textFromChildren();
    433 }
    434 
    435 ScriptLoaderClient* ScriptLoader::client() const
    436 {
    437     if (isHTMLScriptLoader(m_element))
    438         return toHTMLScriptElement(m_element);
    439 
    440     if (isSVGScriptLoader(m_element))
    441         return toSVGScriptElement(m_element);
    442 
    443     ASSERT_NOT_REACHED();
    444     return 0;
    445 }
    446 
    447 ScriptLoader* toScriptLoaderIfPossible(Element* element)
    448 {
    449     if (isHTMLScriptLoader(element))
    450         return toHTMLScriptElement(element)->loader();
    451 
    452     if (isSVGScriptLoader(element))
    453         return toSVGScriptElement(element)->loader();
    454 
    455     return 0;
    456 }
    457 
    458 }
    459