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1 /*
2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4  *           (C) 2001 Dirk Mueller (mueller@kde.org)
5  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
6  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@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 "bindings/v8/ScriptController.h"
28 #include "bindings/v8/ScriptSourceCode.h"
29 #include "core/HTMLNames.h"
30 #include "core/SVGNames.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/HTMLScriptElement.h"
42 #include "core/html/imports/HTMLImport.h"
43 #include "core/html/parser/HTMLParserIdioms.h"
44 #include "core/frame/LocalFrame.h"
45 #include "core/frame/csp/ContentSecurityPolicy.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 
ScriptLoader(Element * element,bool parserInserted,bool alreadyStarted)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 {
69     ASSERT(m_element);
70     if (parserInserted && element->document().scriptableDocumentParser() && !element->document().isInDocumentWrite())
71         m_startLineNumber = element->document().scriptableDocumentParser()->lineNumber();
72 }
73 
~ScriptLoader()74 ScriptLoader::~ScriptLoader()
75 {
76     stopLoadRequest();
77 }
78 
didNotifySubtreeInsertionsToDocument()79 void ScriptLoader::didNotifySubtreeInsertionsToDocument()
80 {
81     if (!m_parserInserted)
82         prepareScript(); // FIXME: Provide a real starting line number here.
83 }
84 
childrenChanged()85 void ScriptLoader::childrenChanged()
86 {
87     if (!m_parserInserted && m_element->inDocument())
88         prepareScript(); // FIXME: Provide a real starting line number here.
89 }
90 
handleSourceAttribute(const String & sourceUrl)91 void ScriptLoader::handleSourceAttribute(const String& sourceUrl)
92 {
93     if (ignoresLoadRequest() || sourceUrl.isEmpty())
94         return;
95 
96     prepareScript(); // FIXME: Provide a real starting line number here.
97 }
98 
handleAsyncAttribute()99 void ScriptLoader::handleAsyncAttribute()
100 {
101     m_forceAsync = false;
102 }
103 
104 // Helper function
isLegacySupportedJavaScriptLanguage(const String & language)105 static bool isLegacySupportedJavaScriptLanguage(const String& language)
106 {
107     // Mozilla 1.8 accepts javascript1.0 - javascript1.7, but WinIE 7 accepts only javascript1.1 - javascript1.3.
108     // Mozilla 1.8 and WinIE 7 both accept javascript and livescript.
109     // WinIE 7 accepts ecmascript and jscript, but Mozilla 1.8 doesn't.
110     // Neither Mozilla 1.8 nor WinIE 7 accept leading or trailing whitespace.
111     // We want to accept all the values that either of these browsers accept, but not other values.
112 
113     // FIXME: This function is not HTML5 compliant. These belong in the MIME registry as "text/javascript<version>" entries.
114     typedef HashSet<String, CaseFoldingHash> LanguageSet;
115     DEFINE_STATIC_LOCAL(LanguageSet, languages, ());
116     if (languages.isEmpty()) {
117         languages.add("javascript");
118         languages.add("javascript1.0");
119         languages.add("javascript1.1");
120         languages.add("javascript1.2");
121         languages.add("javascript1.3");
122         languages.add("javascript1.4");
123         languages.add("javascript1.5");
124         languages.add("javascript1.6");
125         languages.add("javascript1.7");
126         languages.add("livescript");
127         languages.add("ecmascript");
128         languages.add("jscript");
129     }
130 
131     return languages.contains(language);
132 }
133 
dispatchErrorEvent()134 void ScriptLoader::dispatchErrorEvent()
135 {
136     m_element->dispatchEvent(Event::create(EventTypeNames::error));
137 }
138 
dispatchLoadEvent()139 void ScriptLoader::dispatchLoadEvent()
140 {
141     if (ScriptLoaderClient* client = this->client())
142         client->dispatchLoadEvent();
143     setHaveFiredLoadEvent(true);
144 }
145 
isScriptTypeSupported(LegacyTypeSupport supportLegacyTypes) const146 bool ScriptLoader::isScriptTypeSupported(LegacyTypeSupport supportLegacyTypes) const
147 {
148     // FIXME: isLegacySupportedJavaScriptLanguage() is not valid HTML5. It is used here to maintain backwards compatibility with existing layout tests. The specific violations are:
149     // - Allowing type=javascript. type= should only support MIME types, such as text/javascript.
150     // - Allowing a different set of languages for language= and type=. language= supports Javascript 1.1 and 1.4-1.6, but type= does not.
151 
152     String type = client()->typeAttributeValue();
153     String language = client()->languageAttributeValue();
154     if (type.isEmpty() && language.isEmpty())
155         return true; // Assume text/javascript.
156     if (type.isEmpty()) {
157         type = "text/" + language.lower();
158         if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type) || isLegacySupportedJavaScriptLanguage(language))
159             return true;
160     } else if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type.stripWhiteSpace()) || (supportLegacyTypes == AllowLegacyTypeInTypeAttribute && isLegacySupportedJavaScriptLanguage(type))) {
161         return true;
162     }
163 
164     return false;
165 }
166 
167 // http://dev.w3.org/html5/spec/Overview.html#prepare-a-script
prepareScript(const TextPosition & scriptStartPosition,LegacyTypeSupport supportLegacyTypes)168 bool ScriptLoader::prepareScript(const TextPosition& scriptStartPosition, LegacyTypeSupport supportLegacyTypes)
169 {
170     if (m_alreadyStarted)
171         return false;
172 
173     ScriptLoaderClient* client = this->client();
174 
175     bool wasParserInserted;
176     if (m_parserInserted) {
177         wasParserInserted = true;
178         m_parserInserted = false;
179     } else {
180         wasParserInserted = false;
181     }
182 
183     if (wasParserInserted && !client->asyncAttributeValue())
184         m_forceAsync = true;
185 
186     // FIXME: HTML5 spec says we should check that all children are either comments or empty text nodes.
187     if (!client->hasSourceAttribute() && !m_element->firstChild())
188         return false;
189 
190     if (!m_element->inDocument())
191         return false;
192 
193     if (!isScriptTypeSupported(supportLegacyTypes))
194         return false;
195 
196     if (wasParserInserted) {
197         m_parserInserted = true;
198         m_forceAsync = false;
199     }
200 
201     m_alreadyStarted = true;
202 
203     // FIXME: If script is parser inserted, verify it's still in the original document.
204     Document& elementDocument = m_element->document();
205     Document* contextDocument = elementDocument.contextDocument().get();
206 
207     if (!contextDocument || !contextDocument->allowExecutingScripts(m_element))
208         return false;
209 
210     if (!isScriptForEventSupported())
211         return false;
212 
213     if (!client->charsetAttributeValue().isEmpty())
214         m_characterEncoding = client->charsetAttributeValue();
215     else
216         m_characterEncoding = elementDocument.charset();
217 
218     if (client->hasSourceAttribute()) {
219         if (!fetchScript(client->sourceAttributeValue()))
220             return false;
221     }
222 
223     if (client->hasSourceAttribute() && client->deferAttributeValue() && m_parserInserted && !client->asyncAttributeValue()) {
224         m_willExecuteWhenDocumentFinishedParsing = true;
225         m_willBeParserExecuted = true;
226     } else if (client->hasSourceAttribute() && m_parserInserted && !client->asyncAttributeValue()) {
227         m_willBeParserExecuted = true;
228     } else if (!client->hasSourceAttribute() && m_parserInserted && !elementDocument.isRenderingReady()) {
229         m_willBeParserExecuted = true;
230         m_readyToBeParserExecuted = true;
231     } else if (client->hasSourceAttribute() && !client->asyncAttributeValue() && !m_forceAsync) {
232         m_willExecuteInOrder = true;
233         contextDocument->scriptRunner()->queueScriptForExecution(this, m_resource, ScriptRunner::IN_ORDER_EXECUTION);
234         m_resource->addClient(this);
235     } else if (client->hasSourceAttribute()) {
236         contextDocument->scriptRunner()->queueScriptForExecution(this, m_resource, ScriptRunner::ASYNC_EXECUTION);
237         m_resource->addClient(this);
238     } else {
239         // Reset line numbering for nested writes.
240         TextPosition position = elementDocument.isInDocumentWrite() ? TextPosition() : scriptStartPosition;
241         KURL scriptURL = (!elementDocument.isInDocumentWrite() && m_parserInserted) ? elementDocument.url() : KURL();
242         executeScript(ScriptSourceCode(scriptContent(), scriptURL, position));
243     }
244 
245     return true;
246 }
247 
fetchScript(const String & sourceUrl)248 bool ScriptLoader::fetchScript(const String& sourceUrl)
249 {
250     ASSERT(m_element);
251 
252     RefPtrWillBeRawPtr<Document> elementDocument(m_element->document());
253     if (!m_element->inDocument() || m_element->document() != elementDocument)
254         return false;
255 
256     ASSERT(!m_resource);
257     if (!stripLeadingAndTrailingHTMLSpaces(sourceUrl).isEmpty()) {
258         FetchRequest request(ResourceRequest(elementDocument->completeURL(sourceUrl)), m_element->localName());
259 
260         AtomicString crossOriginMode = m_element->fastGetAttribute(HTMLNames::crossoriginAttr);
261         if (!crossOriginMode.isNull())
262             request.setCrossOriginAccessControl(elementDocument->securityOrigin(), crossOriginMode);
263         request.setCharset(scriptCharset());
264 
265         bool isValidScriptNonce = elementDocument->contentSecurityPolicy()->allowScriptNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr));
266         if (isValidScriptNonce)
267             request.setContentSecurityCheck(DoNotCheckContentSecurityPolicy);
268 
269         m_resource = elementDocument->fetcher()->fetchScript(request);
270         m_isExternalScript = true;
271     }
272 
273     if (m_resource)
274         return true;
275 
276     dispatchErrorEvent();
277     return false;
278 }
279 
isHTMLScriptLoader(Element * element)280 bool isHTMLScriptLoader(Element* element)
281 {
282     ASSERT(element);
283     return isHTMLScriptElement(*element);
284 }
285 
isSVGScriptLoader(Element * element)286 bool isSVGScriptLoader(Element* element)
287 {
288     ASSERT(element);
289     return isSVGScriptElement(*element);
290 }
291 
executeScript(const ScriptSourceCode & sourceCode)292 void ScriptLoader::executeScript(const ScriptSourceCode& sourceCode)
293 {
294     ASSERT(m_alreadyStarted);
295 
296     if (sourceCode.isEmpty())
297         return;
298 
299     RefPtrWillBeRawPtr<Document> elementDocument(m_element->document());
300     RefPtrWillBeRawPtr<Document> contextDocument = elementDocument->contextDocument().get();
301     if (!contextDocument)
302         return;
303 
304     LocalFrame* frame = contextDocument->frame();
305 
306     bool shouldBypassMainWorldContentSecurityPolicy = (frame && frame->script().shouldBypassMainWorldContentSecurityPolicy()) || elementDocument->contentSecurityPolicy()->allowScriptNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr)) || elementDocument->contentSecurityPolicy()->allowScriptHash(sourceCode.source());
307 
308     if (!m_isExternalScript && (!shouldBypassMainWorldContentSecurityPolicy && !elementDocument->contentSecurityPolicy()->allowInlineScript(elementDocument->url(), m_startLineNumber)))
309         return;
310 
311     if (m_isExternalScript) {
312         ScriptResource* resource = m_resource ? m_resource.get() : sourceCode.resource();
313         if (resource && !resource->mimeTypeAllowedByNosniff()) {
314             contextDocument->addConsoleMessage(SecurityMessageSource, ErrorMessageLevel, "Refused to execute script from '" + resource->url().elidedString() + "' because its MIME type ('" + resource->mimeType() + "') is not executable, and strict MIME type checking is enabled.");
315             return;
316         }
317     }
318 
319     if (frame) {
320         const bool isImportedScript = contextDocument != elementDocument;
321         // http://www.whatwg.org/specs/web-apps/current-work/#execute-the-script-block step 2.3
322         // with additional support for HTML imports.
323         IgnoreDestructiveWriteCountIncrementer ignoreDestructiveWriteCountIncrementer(m_isExternalScript || isImportedScript ? contextDocument.get() : 0);
324 
325         if (isHTMLScriptLoader(m_element))
326             contextDocument->pushCurrentScript(toHTMLScriptElement(m_element));
327 
328         AccessControlStatus corsCheck = NotSharableCrossOrigin;
329         if (!m_isExternalScript || (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 
stopLoadRequest()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 
execute(ScriptResource * resource)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 
notifyFinished(Resource * resource)366 void ScriptLoader::notifyFinished(Resource* resource)
367 {
368     ASSERT(!m_willBeParserExecuted);
369 
370     RefPtrWillBeRawPtr<Document> elementDocument(m_element->document());
371     RefPtrWillBeRawPtr<Document> contextDocument = elementDocument->contextDocument().get();
372     if (!contextDocument)
373         return;
374 
375     // Resource possibly invokes this notifyFinished() more than
376     // once because ScriptLoader doesn't unsubscribe itself from
377     // Resource here and does it in execute() instead.
378     // We use m_resource to check if this function is already called.
379     ASSERT_UNUSED(resource, resource == m_resource);
380     if (!m_resource)
381         return;
382     if (m_resource->errorOccurred()) {
383         dispatchErrorEvent();
384         contextDocument->scriptRunner()->notifyScriptLoadError(this, m_willExecuteInOrder ? ScriptRunner::IN_ORDER_EXECUTION : ScriptRunner::ASYNC_EXECUTION);
385         return;
386     }
387     if (m_willExecuteInOrder)
388         contextDocument->scriptRunner()->notifyScriptReady(this, ScriptRunner::IN_ORDER_EXECUTION);
389     else
390         contextDocument->scriptRunner()->notifyScriptReady(this, ScriptRunner::ASYNC_EXECUTION);
391 
392     m_resource = 0;
393 }
394 
ignoresLoadRequest() const395 bool ScriptLoader::ignoresLoadRequest() const
396 {
397     return m_alreadyStarted || m_isExternalScript || m_parserInserted || !element() || !element()->inDocument();
398 }
399 
isScriptForEventSupported() const400 bool ScriptLoader::isScriptForEventSupported() const
401 {
402     String eventAttribute = client()->eventAttributeValue();
403     String forAttribute = client()->forAttributeValue();
404     if (!eventAttribute.isEmpty() && !forAttribute.isEmpty()) {
405         forAttribute = forAttribute.stripWhiteSpace();
406         if (!equalIgnoringCase(forAttribute, "window"))
407             return false;
408 
409         eventAttribute = eventAttribute.stripWhiteSpace();
410         if (!equalIgnoringCase(eventAttribute, "onload") && !equalIgnoringCase(eventAttribute, "onload()"))
411             return false;
412     }
413     return true;
414 }
415 
scriptContent() const416 String ScriptLoader::scriptContent() const
417 {
418     return m_element->textFromChildren();
419 }
420 
client() const421 ScriptLoaderClient* ScriptLoader::client() const
422 {
423     if (isHTMLScriptLoader(m_element))
424         return toHTMLScriptElement(m_element);
425 
426     if (isSVGScriptLoader(m_element))
427         return toSVGScriptElement(m_element);
428 
429     ASSERT_NOT_REACHED();
430     return 0;
431 }
432 
toScriptLoaderIfPossible(Element * element)433 ScriptLoader* toScriptLoaderIfPossible(Element* element)
434 {
435     if (isHTMLScriptLoader(element))
436         return toHTMLScriptElement(element)->loader();
437 
438     if (isSVGScriptLoader(element))
439         return toSVGScriptElement(element)->loader();
440 
441     return 0;
442 }
443 
444 }
445