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/*
* (C) 1999-2003 Lars Knoll (knoll@kde.org)
* Copyright (C) 2004-2017 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "StyleSheetContents.h"
#include "CSSImportRule.h"
#include "CSSParser.h"
#include "CSSStyleSheet.h"
#include "CachedCSSStyleSheet.h"
#include "ContentRuleListResults.h"
#include "Document.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "MediaList.h"
#include "Node.h"
#include "Page.h"
#include "PageConsoleClient.h"
#include "ResourceLoadInfo.h"
#include "RuleSet.h"
#include "SecurityOrigin.h"
#include "StyleRule.h"
#include "StyleRuleImport.h"
#include <wtf/Deque.h>
#include <wtf/NeverDestroyed.h>
#include <wtf/Ref.h>
#if ENABLE(CONTENT_EXTENSIONS)
#include "UserContentController.h"
#endif
namespace WebCore {
// Rough size estimate for the memory cache.
unsigned StyleSheetContents::estimatedSizeInBytes() const
{
// Note that this does not take into account size of the strings hanging from various objects.
// The assumption is that nearly all of of them are atoms that would exist anyway.
unsigned size = sizeof(*this);
// FIXME: This ignores the children of media and region rules.
// Most rules are StyleRules.
size += ruleCount() * StyleRule::averageSizeInBytes();
for (unsigned i = 0; i < m_importRules.size(); ++i) {
if (StyleSheetContents* sheet = m_importRules[i]->styleSheet())
size += sheet->estimatedSizeInBytes();
}
return size;
}
StyleSheetContents::StyleSheetContents(StyleRuleImport* ownerRule, const String& originalURL, const CSSParserContext& context)
: m_ownerRule(ownerRule)
, m_originalURL(originalURL)
, m_defaultNamespace(starAtom())
, m_isUserStyleSheet(ownerRule && ownerRule->parentStyleSheet() && ownerRule->parentStyleSheet()->isUserStyleSheet())
, m_parserContext(context)
{
}
StyleSheetContents::StyleSheetContents(const StyleSheetContents& o)
: RefCounted<StyleSheetContents>()
, m_ownerRule(0)
, m_originalURL(o.m_originalURL)
, m_encodingFromCharsetRule(o.m_encodingFromCharsetRule)
, m_importRules(o.m_importRules.size())
, m_namespaceRules(o.m_namespaceRules.size())
, m_childRules(o.m_childRules.size())
, m_namespaces(o.m_namespaces)
, m_defaultNamespace(o.m_defaultNamespace)
, m_isUserStyleSheet(o.m_isUserStyleSheet)
, m_loadCompleted(true)
, m_hasSyntacticallyValidCSSHeader(o.m_hasSyntacticallyValidCSSHeader)
, m_usesStyleBasedEditability(o.m_usesStyleBasedEditability)
, m_parserContext(o.m_parserContext)
{
ASSERT(o.isCacheable());
// FIXME: Copy import rules.
ASSERT(o.m_importRules.isEmpty());
for (unsigned i = 0; i < m_childRules.size(); ++i)
m_childRules[i] = o.m_childRules[i]->copy();
}
StyleSheetContents::~StyleSheetContents()
{
clearRules();
}
bool StyleSheetContents::isCacheable() const
{
// FIXME: Support copying import rules.
if (!m_importRules.isEmpty())
return false;
// FIXME: Support cached stylesheets in import rules.
if (m_ownerRule)
return false;
// This would require dealing with multiple clients for load callbacks.
if (!m_loadCompleted)
return false;
if (m_didLoadErrorOccur)
return false;
// It is not the original sheet anymore.
if (m_isMutable)
return false;
// If the header is valid we are not going to need to check the SecurityOrigin.
// FIXME: Valid mime type avoids the check too.
if (!m_hasSyntacticallyValidCSSHeader)
return false;
return true;
}
void StyleSheetContents::parserAppendRule(Ref<StyleRuleBase>&& rule)
{
ASSERT(!rule->isCharsetRule());
if (is<StyleRuleImport>(rule)) {
// Parser enforces that @import rules come before anything else except @charset.
ASSERT(m_childRules.isEmpty());
m_importRules.append(downcast<StyleRuleImport>(rule.ptr()));
m_importRules.last()->setParentStyleSheet(this);
m_importRules.last()->requestStyleSheet();
return;
}
if (is<StyleRuleNamespace>(rule)) {
// Parser enforces that @namespace rules come before all rules other than
// import/charset rules
ASSERT(m_childRules.isEmpty());
StyleRuleNamespace& namespaceRule = downcast<StyleRuleNamespace>(rule.get());
parserAddNamespace(namespaceRule.prefix(), namespaceRule.uri());
m_namespaceRules.append(downcast<StyleRuleNamespace>(rule.ptr()));
return;
}
if (is<StyleRuleMedia>(rule))
reportMediaQueryWarningIfNeeded(singleOwnerDocument(), downcast<StyleRuleMedia>(rule.get()).mediaQueries());
// NOTE: The selector list has to fit into RuleData. <http://webkit.org/b/118369>
// If we're adding a rule with a huge number of selectors, split it up into multiple rules
if (is<StyleRule>(rule) && downcast<StyleRule>(rule.get()).selectorList().componentCount() > Style::RuleData::maximumSelectorComponentCount) {
m_childRules.appendVector(downcast<StyleRule>(rule.get()).splitIntoMultipleRulesWithMaximumSelectorComponentCount(Style::RuleData::maximumSelectorComponentCount));
return;
}
m_childRules.append(WTFMove(rule));
}
StyleRuleBase* StyleSheetContents::ruleAt(unsigned index) const
{
ASSERT_WITH_SECURITY_IMPLICATION(index < ruleCount());
unsigned childVectorIndex = index;
if (childVectorIndex < m_importRules.size())
return m_importRules[childVectorIndex].get();
childVectorIndex -= m_importRules.size();
if (childVectorIndex < m_namespaceRules.size())
return m_namespaceRules[childVectorIndex].get();
childVectorIndex -= m_namespaceRules.size();
return m_childRules[childVectorIndex].get();
}
unsigned StyleSheetContents::ruleCount() const
{
unsigned result = 0;
result += m_importRules.size();
result += m_namespaceRules.size();
result += m_childRules.size();
return result;
}
void StyleSheetContents::clearCharsetRule()
{
m_encodingFromCharsetRule = String();
}
void StyleSheetContents::clearRules()
{
for (unsigned i = 0; i < m_importRules.size(); ++i) {
ASSERT(m_importRules.at(i)->parentStyleSheet() == this);
m_importRules[i]->clearParentStyleSheet();
}
m_importRules.clear();
m_namespaceRules.clear();
m_childRules.clear();
clearCharsetRule();
}
void StyleSheetContents::parserSetEncodingFromCharsetRule(const String& encoding)
{
// Parser enforces that there is ever only one @charset.
ASSERT(m_encodingFromCharsetRule.isNull());
m_encodingFromCharsetRule = encoding;
}
bool StyleSheetContents::wrapperInsertRule(Ref<StyleRuleBase>&& rule, unsigned index)
{
ASSERT(m_isMutable);
ASSERT_WITH_SECURITY_IMPLICATION(index <= ruleCount());
// Parser::parseRule doesn't currently allow @charset so we don't need to deal with it.
ASSERT(!rule->isCharsetRule());
unsigned childVectorIndex = index;
if (childVectorIndex < m_importRules.size() || (childVectorIndex == m_importRules.size() && rule->isImportRule())) {
// Inserting non-import rule before @import is not allowed.
if (!is<StyleRuleImport>(rule))
return false;
m_importRules.insert(childVectorIndex, downcast<StyleRuleImport>(rule.ptr()));
m_importRules[childVectorIndex]->setParentStyleSheet(this);
m_importRules[childVectorIndex]->requestStyleSheet();
// FIXME: Stylesheet doesn't actually change meaningfully before the imported sheets are loaded.
return true;
}
// Inserting @import rule after a non-import rule is not allowed.
if (is<StyleRuleImport>(rule))
return false;
childVectorIndex -= m_importRules.size();
if (childVectorIndex < m_namespaceRules.size() || (childVectorIndex == m_namespaceRules.size() && rule->isNamespaceRule())) {
// Inserting non-namespace rules other than import rule before @namespace is
// not allowed.
if (!is<StyleRuleNamespace>(rule))
return false;
// Inserting @namespace rule when rules other than import/namespace/charset
// are present is not allowed.
if (!m_childRules.isEmpty())
return false;
StyleRuleNamespace& namespaceRule = downcast<StyleRuleNamespace>(rule.get());
m_namespaceRules.insert(index, downcast<StyleRuleNamespace>(rule.ptr()));
// For now to be compatible with IE and Firefox if a namespace rule with the same
// prefix is added, it overwrites previous ones.
// FIXME: The eventual correct behavior would be to ensure that the last value in
// the list wins.
parserAddNamespace(namespaceRule.prefix(), namespaceRule.uri());
return true;
}
if (is<StyleRuleNamespace>(rule))
return false;
childVectorIndex -= m_namespaceRules.size();
// If the number of selectors would overflow RuleData, we drop the operation.
if (is<StyleRule>(rule) && downcast<StyleRule>(rule.get()).selectorList().componentCount() > Style::RuleData::maximumSelectorComponentCount)
return false;
m_childRules.insert(childVectorIndex, WTFMove(rule));
return true;
}
void StyleSheetContents::wrapperDeleteRule(unsigned index)
{
ASSERT(m_isMutable);
ASSERT_WITH_SECURITY_IMPLICATION(index < ruleCount());
unsigned childVectorIndex = index;
if (childVectorIndex < m_importRules.size()) {
m_importRules[childVectorIndex]->clearParentStyleSheet();
m_importRules.remove(childVectorIndex);
return;
}
childVectorIndex -= m_importRules.size();
if (childVectorIndex < m_namespaceRules.size()) {
if (!m_childRules.isEmpty())
return;
m_namespaceRules.remove(childVectorIndex);
return;
}
childVectorIndex -= m_namespaceRules.size();
m_childRules.remove(childVectorIndex);
}
void StyleSheetContents::parserAddNamespace(const AtomString& prefix, const AtomString& uri)
{
ASSERT(!uri.isNull());
if (prefix.isNull()) {
m_defaultNamespace = uri;
return;
}
PrefixNamespaceURIMap::AddResult result = m_namespaces.add(prefix, uri);
if (result.isNewEntry)
return;
result.iterator->value = uri;
}
const AtomString& StyleSheetContents::namespaceURIFromPrefix(const AtomString& prefix)
{
PrefixNamespaceURIMap::const_iterator it = m_namespaces.find(prefix);
if (it == m_namespaces.end())
return nullAtom();
return it->value;
}
void StyleSheetContents::parseAuthorStyleSheet(const CachedCSSStyleSheet* cachedStyleSheet, const SecurityOrigin* securityOrigin)
{
bool isSameOriginRequest = securityOrigin && securityOrigin->canRequest(baseURL());
CachedCSSStyleSheet::MIMETypeCheckHint mimeTypeCheckHint = isStrictParserMode(m_parserContext.mode) || !isSameOriginRequest ? CachedCSSStyleSheet::MIMETypeCheckHint::Strict : CachedCSSStyleSheet::MIMETypeCheckHint::Lax;
bool hasValidMIMEType = true;
String sheetText = cachedStyleSheet->sheetText(mimeTypeCheckHint, &hasValidMIMEType);
if (!hasValidMIMEType) {
ASSERT(sheetText.isNull());
if (auto* document = singleOwnerDocument()) {
if (auto* page = document->page()) {
if (isStrictParserMode(m_parserContext.mode))
page->console().addMessage(MessageSource::Security, MessageLevel::Error, makeString("Did not parse stylesheet at '", cachedStyleSheet->url().stringCenterEllipsizedToLength(), "' because non CSS MIME types are not allowed in strict mode."));
else if (!cachedStyleSheet->mimeTypeAllowedByNosniff())
page->console().addMessage(MessageSource::Security, MessageLevel::Error, makeString("Did not parse stylesheet at '", cachedStyleSheet->url().stringCenterEllipsizedToLength(), "' because non CSS MIME types are not allowed when 'X-Content-Type: nosniff' is given."));
else
page->console().addMessage(MessageSource::Security, MessageLevel::Error, makeString("Did not parse stylesheet at '", cachedStyleSheet->url().stringCenterEllipsizedToLength(), "' because non CSS MIME types are not allowed for cross-origin stylesheets."));
}
}
return;
}
CSSParser(parserContext()).parseSheet(this, sheetText, CSSParser::RuleParsing::Deferred);
}
bool StyleSheetContents::parseString(const String& sheetText)
{
CSSParser p(parserContext());
p.parseSheet(this, sheetText, parserContext().mode != UASheetMode ? CSSParser::RuleParsing::Deferred : CSSParser::RuleParsing::Normal);
return true;
}
bool StyleSheetContents::isLoading() const
{
for (unsigned i = 0; i < m_importRules.size(); ++i) {
if (m_importRules[i]->isLoading())
return true;
}
return false;
}
void StyleSheetContents::checkLoaded()
{
if (isLoading())
return;
Ref<StyleSheetContents> protectedThis(*this);
StyleSheetContents* parentSheet = parentStyleSheet();
if (parentSheet) {
parentSheet->checkLoaded();
m_loadCompleted = true;
return;
}
RefPtr<Node> ownerNode = singleOwnerNode();
if (!ownerNode) {
m_loadCompleted = true;
return;
}
m_loadCompleted = ownerNode->sheetLoaded();
if (m_loadCompleted)
ownerNode->notifyLoadedSheetAndAllCriticalSubresources(m_didLoadErrorOccur);
}
void StyleSheetContents::notifyLoadedSheet(const CachedCSSStyleSheet* sheet)
{
ASSERT(sheet);
m_didLoadErrorOccur |= sheet->errorOccurred();
m_didLoadErrorOccur |= !sheet->mimeTypeAllowedByNosniff();
}
void StyleSheetContents::startLoadingDynamicSheet()
{
if (Node* owner = singleOwnerNode())
owner->startLoadingDynamicSheet();
}
StyleSheetContents* StyleSheetContents::rootStyleSheet() const
{
const StyleSheetContents* root = this;
while (root->parentStyleSheet())
root = root->parentStyleSheet();
return const_cast<StyleSheetContents*>(root);
}
Node* StyleSheetContents::singleOwnerNode() const
{
StyleSheetContents* root = rootStyleSheet();
if (root->m_clients.isEmpty())
return 0;
ASSERT(root->m_clients.size() == 1);
return root->m_clients[0]->ownerNode();
}
Document* StyleSheetContents::singleOwnerDocument() const
{
Node* ownerNode = singleOwnerNode();
return ownerNode ? &ownerNode->document() : 0;
}
URL StyleSheetContents::completeURL(const String& url) const
{
return m_parserContext.completeURL(url);
}
static bool traverseRulesInVector(const Vector<RefPtr<StyleRuleBase>>& rules, const WTF::Function<bool (const StyleRuleBase&)>& handler)
{
for (auto& rule : rules) {
if (handler(*rule))
return true;
switch (rule->type()) {
case StyleRuleType::Media: {
auto* childRules = downcast<StyleRuleMedia>(*rule).childRulesWithoutDeferredParsing();
if (childRules && traverseRulesInVector(*childRules, handler))
return true;
break;
}
case StyleRuleType::Import:
ASSERT_NOT_REACHED();
break;
case StyleRuleType::Style:
case StyleRuleType::FontFace:
case StyleRuleType::Page:
case StyleRuleType::Keyframes:
case StyleRuleType::Namespace:
case StyleRuleType::Unknown:
case StyleRuleType::Charset:
case StyleRuleType::Keyframe:
case StyleRuleType::Supports:
#if ENABLE(CSS_DEVICE_ADAPTATION)
case StyleRuleType::Viewport:
#endif
break;
}
}
return false;
}
bool StyleSheetContents::traverseRules(const WTF::Function<bool (const StyleRuleBase&)>& handler) const
{
for (auto& importRule : m_importRules) {
if (handler(*importRule))
return true;
auto* importedStyleSheet = importRule->styleSheet();
if (importedStyleSheet && importedStyleSheet->traverseRules(handler))
return true;
}
return traverseRulesInVector(m_childRules, handler);
}
bool StyleSheetContents::traverseSubresources(const WTF::Function<bool (const CachedResource&)>& handler) const
{
return traverseRules([&] (const StyleRuleBase& rule) {
switch (rule.type()) {
case StyleRuleType::Style: {
auto* properties = downcast<StyleRule>(rule).propertiesWithoutDeferredParsing();
return properties && properties->traverseSubresources(handler);
}
case StyleRuleType::FontFace:
return downcast<StyleRuleFontFace>(rule).properties().traverseSubresources(handler);
case StyleRuleType::Import:
if (auto* cachedResource = downcast<StyleRuleImport>(rule).cachedCSSStyleSheet())
return handler(*cachedResource);
return false;
case StyleRuleType::Media:
case StyleRuleType::Page:
case StyleRuleType::Keyframes:
case StyleRuleType::Namespace:
case StyleRuleType::Unknown:
case StyleRuleType::Charset:
case StyleRuleType::Keyframe:
case StyleRuleType::Supports:
#if ENABLE(CSS_DEVICE_ADAPTATION)
case StyleRuleType::Viewport:
#endif
return false;
};
ASSERT_NOT_REACHED();
return false;
});
}
bool StyleSheetContents::subresourcesAllowReuse(CachePolicy cachePolicy, FrameLoader& loader) const
{
bool hasFailedOrExpiredResources = traverseSubresources([cachePolicy, &loader](const CachedResource& resource) {
if (resource.loadFailedOrCanceled())
return true;
// We can't revalidate subresources individually so don't use reuse the parsed sheet if they need revalidation.
if (resource.makeRevalidationDecision(cachePolicy) != CachedResource::RevalidationDecision::No)
return true;
#if ENABLE(CONTENT_EXTENSIONS)
// If a cached subresource is blocked or made HTTPS by a content blocker, we cannot reuse the cached stylesheet.
auto* page = loader.frame().page();
auto* documentLoader = loader.documentLoader();
if (page && documentLoader) {
const auto& request = resource.resourceRequest();
auto results = page->userContentProvider().processContentRuleListsForLoad(request.url(), ContentExtensions::toResourceType(resource.type()), *documentLoader);
if (results.summary.blockedLoad || results.summary.madeHTTPS)
return true;
}
#else
UNUSED_PARAM(loader);
#endif
return false;
});
return !hasFailedOrExpiredResources;
}
bool StyleSheetContents::isLoadingSubresources() const
{
return traverseSubresources([](const CachedResource& resource) {
return resource.isLoading();
});
}
StyleSheetContents* StyleSheetContents::parentStyleSheet() const
{
return m_ownerRule ? m_ownerRule->parentStyleSheet() : 0;
}
void StyleSheetContents::registerClient(CSSStyleSheet* sheet)
{
ASSERT(!m_clients.contains(sheet));
m_clients.append(sheet);
}
void StyleSheetContents::unregisterClient(CSSStyleSheet* sheet)
{
bool removed = m_clients.removeFirst(sheet);
ASSERT_UNUSED(removed, removed);
}
void StyleSheetContents::addedToMemoryCache()
{
ASSERT(isCacheable());
++m_inMemoryCacheCount;
}
void StyleSheetContents::removedFromMemoryCache()
{
ASSERT(m_inMemoryCacheCount);
ASSERT(isCacheable());
--m_inMemoryCacheCount;
}
void StyleSheetContents::shrinkToFit()
{
m_importRules.shrinkToFit();
m_childRules.shrinkToFit();
}
}