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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*
* A base class which implements nsIStyleSheetLinkingElement and can
* be subclassed by various content nodes that want to load
* stylesheets (<style>, <link>, processing instructions, etc).
*/
#include "mozilla/dom/LinkStyle.h"
#include "mozilla/StyleSheet.h"
#include "mozilla/StyleSheetInlines.h"
#include "mozilla/css/Loader.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/FragmentOrElement.h"
#include "mozilla/dom/HTMLLinkElement.h"
#include "mozilla/dom/HTMLStyleElement.h"
#include "mozilla/dom/SVGStyleElement.h"
#include "mozilla/dom/ShadowRoot.h"
#include "mozilla/dom/SRILogHelper.h"
#include "mozilla/Preferences.h"
#include "mozilla/StaticPrefs_dom.h"
#include "nsIContent.h"
#include "mozilla/dom/Document.h"
#include "nsUnicharUtils.h"
#include "nsCRT.h"
#include "nsXPCOMCIDInternal.h"
#include "nsUnicharInputStream.h"
#include "nsContentUtils.h"
#include "nsStyleUtil.h"
#include "nsQueryObject.h"
namespace mozilla::dom {
LinkStyle::SheetInfo::SheetInfo(
const Document& aDocument, nsIContent* aContent,
already_AddRefed<nsIURI> aURI,
already_AddRefed<nsIPrincipal> aTriggeringPrincipal,
already_AddRefed<nsIReferrerInfo> aReferrerInfo,
mozilla::CORSMode aCORSMode, const nsAString& aTitle,
const nsAString& aMedia, const nsAString& aIntegrity,
const nsAString& aNonce, HasAlternateRel aHasAlternateRel,
IsInline aIsInline, IsExplicitlyEnabled aIsExplicitlyEnabled,
FetchPriority aFetchPriority)
: mContent(aContent),
mURI(aURI),
mTriggeringPrincipal(aTriggeringPrincipal),
mReferrerInfo(aReferrerInfo),
mCORSMode(aCORSMode),
mTitle(aTitle),
mMedia(aMedia),
mIntegrity(aIntegrity),
mNonce(aNonce),
mFetchPriority(aFetchPriority),
mHasAlternateRel(aHasAlternateRel == HasAlternateRel::Yes),
mIsInline(aIsInline == IsInline::Yes),
mIsExplicitlyEnabled(aIsExplicitlyEnabled) {
MOZ_ASSERT(!mIsInline || aContent);
MOZ_ASSERT_IF(aContent, aContent->OwnerDoc() == &aDocument);
MOZ_ASSERT(mReferrerInfo);
MOZ_ASSERT(mIntegrity.IsEmpty() || !mIsInline,
"Integrity only applies to <link>");
}
LinkStyle::SheetInfo::~SheetInfo() = default;
LinkStyle::LinkStyle() = default;
LinkStyle::~LinkStyle() { LinkStyle::SetStyleSheet(nullptr); }
StyleSheet* LinkStyle::GetSheetForBindings() const {
if (mStyleSheet && mStyleSheet->IsComplete()) {
return mStyleSheet;
}
return nullptr;
}
void LinkStyle::GetTitleAndMediaForElement(const Element& aSelf,
nsString& aTitle, nsString& aMedia) {
// Only honor title as stylesheet name for elements in the document (that is,
// ignore for Shadow DOM), per [1] and [2]. See [3].
//
if (aSelf.IsInUncomposedDoc()) {
aSelf.GetAttr(nsGkAtoms::title, aTitle);
aTitle.CompressWhitespace();
}
aSelf.GetAttr(nsGkAtoms::media, aMedia);
// The HTML5 spec is formulated in terms of the CSSOM spec, which specifies
// that media queries should be ASCII lowercased during serialization.
//
// FIXME(emilio): How does it matter? This is going to be parsed anyway, CSS
// should take care of serializing it properly.
nsContentUtils::ASCIIToLower(aMedia);
}
bool LinkStyle::IsCSSMimeTypeAttributeForStyleElement(const Element& aSelf) {
// Per
// step 4, for style elements we should only accept empty and "text/css" type
// attribute values.
nsAutoString type;
aSelf.GetAttr(nsGkAtoms::type, type);
return type.IsEmpty() || type.LowerCaseEqualsLiteral("text/css");
}
void LinkStyle::Unlink() { LinkStyle::SetStyleSheet(nullptr); }
void LinkStyle::Traverse(nsCycleCollectionTraversalCallback& cb) {
LinkStyle* tmp = this;
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleSheet);
}
void LinkStyle::SetStyleSheet(StyleSheet* aStyleSheet) {
if (mStyleSheet) {
mStyleSheet->SetOwningNode(nullptr);
}
mStyleSheet = aStyleSheet;
if (mStyleSheet) {
mStyleSheet->SetOwningNode(&AsContent());
}
}
void LinkStyle::GetCharset(nsAString& aCharset) { aCharset.Truncate(); }
static uint32_t ToLinkMask(const nsAString& aLink) {
// Keep this in sync with sSupportedRelValues in HTMLLinkElement.cpp
uint32_t mask = 0;
if (aLink.EqualsLiteral("prefetch")) {
mask = LinkStyle::ePREFETCH;
} else if (aLink.EqualsLiteral("dns-prefetch")) {
mask = LinkStyle::eDNS_PREFETCH;
} else if (aLink.EqualsLiteral("stylesheet")) {
mask = LinkStyle::eSTYLESHEET;
} else if (aLink.EqualsLiteral("next")) {
mask = LinkStyle::eNEXT;
} else if (aLink.EqualsLiteral("alternate")) {
mask = LinkStyle::eALTERNATE;
} else if (aLink.EqualsLiteral("preconnect")) {
mask = LinkStyle::ePRECONNECT;
} else if (aLink.EqualsLiteral("preload")) {
mask = LinkStyle::ePRELOAD;
} else if (aLink.EqualsLiteral("modulepreload")) {
mask = LinkStyle::eMODULE_PRELOAD;
}
return mask;
}
uint32_t LinkStyle::ParseLinkTypes(const nsAString& aTypes) {
uint32_t linkMask = 0;
nsAString::const_iterator start, done;
aTypes.BeginReading(start);
aTypes.EndReading(done);
if (start == done) return linkMask;
nsAString::const_iterator current(start);
bool inString = !nsContentUtils::IsHTMLWhitespace(*current);
nsAutoString subString;
while (current != done) {
if (nsContentUtils::IsHTMLWhitespace(*current)) {
if (inString) {
nsContentUtils::ASCIIToLower(Substring(start, current), subString);
linkMask |= ToLinkMask(subString);
inString = false;
}
} else {
if (!inString) {
start = current;
inString = true;
}
}
++current;
}
if (inString) {
nsContentUtils::ASCIIToLower(Substring(start, current), subString);
linkMask |= ToLinkMask(subString);
}
return linkMask;
}
Result<LinkStyle::Update, nsresult> LinkStyle::UpdateStyleSheetInternal(
Document* aOldDocument, ShadowRoot* aOldShadowRoot,
ForceUpdate aForceUpdate) {
return DoUpdateStyleSheet(aOldDocument, aOldShadowRoot, nullptr,
aForceUpdate);
}
LinkStyle* LinkStyle::FromNode(Element& aElement) {
nsAtom* name = aElement.NodeInfo()->NameAtom();
if (name == nsGkAtoms::link) {
MOZ_ASSERT(aElement.IsHTMLElement() == !!aElement.AsLinkStyle());
return aElement.IsHTMLElement() ? static_cast<HTMLLinkElement*>(&aElement)
: nullptr;
}
if (name == nsGkAtoms::style) {
if (aElement.IsHTMLElement()) {
MOZ_ASSERT(aElement.AsLinkStyle());
return static_cast<HTMLStyleElement*>(&aElement);
}
if (aElement.IsSVGElement()) {
MOZ_ASSERT(aElement.AsLinkStyle());
return static_cast<SVGStyleElement*>(&aElement);
}
}
MOZ_ASSERT(!aElement.AsLinkStyle());
return nullptr;
}
void LinkStyle::BindToTree() {
if (mUpdatesEnabled) {
nsContentUtils::AddScriptRunner(NS_NewRunnableFunction(
"LinkStyle::BindToTree",
[this, pin = RefPtr{&AsContent()}] { UpdateStyleSheetInternal(); }));
}
}
Result<LinkStyle::Update, nsresult> LinkStyle::DoUpdateStyleSheet(
Document* aOldDocument, ShadowRoot* aOldShadowRoot,
nsICSSLoaderObserver* aObserver, ForceUpdate aForceUpdate) {
nsIContent& thisContent = AsContent();
if (thisContent.IsInSVGUseShadowTree()) {
// Stylesheets in <use>-cloned subtrees are disabled until we figure out
// how they should behave.
return Update{};
}
if (mStyleSheet && (aOldDocument || aOldShadowRoot)) {
MOZ_ASSERT(!(aOldDocument && aOldShadowRoot),
"ShadowRoot content is never in document, thus "
"there should not be a old document and old "
"ShadowRoot simultaneously.");
// We're removing the link element from the document or shadow tree, unload
// the stylesheet.
//
// We want to do this even if updates are disabled, since otherwise a sheet
// with a stale linking element pointer will be hanging around -- not good!
if (mStyleSheet->IsComplete()) {
if (aOldShadowRoot) {
aOldShadowRoot->RemoveStyleSheet(*mStyleSheet);
} else {
aOldDocument->RemoveStyleSheet(*mStyleSheet);
}
}
SetStyleSheet(nullptr);
}
Document* doc = thisContent.GetComposedDoc();
if (!doc || !doc->CSSLoader() || !doc->CSSLoader()->GetEnabled()) {
return Update{};
}
// When static documents are created, stylesheets are cloned manually.
if (!mUpdatesEnabled || doc->IsStaticDocument()) {
return Update{};
}
Maybe<SheetInfo> info = GetStyleSheetInfo();
if (aForceUpdate == ForceUpdate::No && mStyleSheet && info &&
!info->mIsInline && info->mURI) {
if (nsIURI* oldURI = mStyleSheet->GetSheetURI()) {
bool equal;
nsresult rv = oldURI->Equals(info->mURI, &equal);
if (NS_SUCCEEDED(rv) && equal) {
return Update{};
}
}
}
if (mStyleSheet) {
if (mStyleSheet->IsComplete()) {
if (thisContent.IsInShadowTree()) {
ShadowRoot* containingShadow = thisContent.GetContainingShadow();
// Could be null only during unlink.
if (MOZ_LIKELY(containingShadow)) {
containingShadow->RemoveStyleSheet(*mStyleSheet);
}
} else {
doc->RemoveStyleSheet(*mStyleSheet);
}
}
SetStyleSheet(nullptr);
}
if (!info) {
return Update{};
}
if (!info->mURI && !info->mIsInline) {
// If href is empty and this is not inline style then just bail
return Update{};
}
if (info->mIsInline) {
nsAutoString text;
if (!nsContentUtils::GetNodeTextContent(&thisContent, false, text,
fallible)) {
return Err(NS_ERROR_OUT_OF_MEMORY);
}
MOZ_ASSERT(thisContent.NodeInfo()->NameAtom() != nsGkAtoms::link,
"<link> is not 'inline', and needs different CSP checks");
MOZ_ASSERT(thisContent.IsElement());
nsresult rv = NS_OK;
if (!nsStyleUtil::CSPAllowsInlineStyle(
thisContent.AsElement(), doc, info->mTriggeringPrincipal,
mLineNumber, mColumnNumber, text, &rv)) {
if (NS_FAILED(rv)) {
return Err(rv);
}
return Update{};
}
// Parse the style sheet.
return doc->CSSLoader()->LoadInlineStyle(*info, text, aObserver);
}
if (thisContent.IsElement()) {
nsAutoString integrity;
thisContent.AsElement()->GetAttr(nsGkAtoms::integrity, integrity);
if (!integrity.IsEmpty()) {
MOZ_LOG(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug,
("LinkStyle::DoUpdateStyleSheet, integrity=%s",
NS_ConvertUTF16toUTF8(integrity).get()));
}
}
auto resultOrError = doc->CSSLoader()->LoadStyleLink(*info, aObserver);
if (resultOrError.isErr()) {
// Don't propagate LoadStyleLink() errors further than this, since some
// consumers (e.g. nsXMLContentSink) will completely abort on innocuous
// things like a stylesheet load being blocked by the security system.
return Update{};
}
return resultOrError;
}
} // namespace mozilla::dom