gecko-dev/image/ImageCacheKey.cpp

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6.7 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "ImageCacheKey.h"
#include <utility>
#include "mozilla/ContentBlocking.h"
#include "mozilla/HashFunctions.h"
#include "mozilla/StorageAccess.h"
#include "mozilla/Unused.h"
#include "mozilla/dom/BlobURLProtocolHandler.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/ServiceWorkerManager.h"
#include "nsContentUtils.h"
#include "nsHashKeys.h"
#include "nsLayoutUtils.h"
#include "nsPrintfCString.h"
#include "nsString.h"
namespace mozilla {
using namespace dom;
namespace image {
static Maybe<uint64_t> BlobSerial(nsIURI* aURI) {
nsAutoCString spec;
aURI->GetSpec(spec);
RefPtr<BlobImpl> blob;
if (NS_SUCCEEDED(NS_GetBlobForBlobURISpec(spec, getter_AddRefs(blob))) &&
blob) {
return Some(blob->GetSerialNumber());
}
return Nothing();
}
ImageCacheKey::ImageCacheKey(nsIURI* aURI, const OriginAttributes& aAttrs,
Document* aDocument)
: mURI(aURI),
mOriginAttributes(aAttrs),
mControlledDocument(GetSpecialCaseDocumentToken(aDocument, aURI)),
mTopLevelBaseDomain(GetTopLevelBaseDomain(aDocument, aURI)),
mIsChrome(false) {
if (mURI->SchemeIs("blob")) {
mBlobSerial = BlobSerial(mURI);
} else if (mURI->SchemeIs("chrome")) {
mIsChrome = true;
}
}
ImageCacheKey::ImageCacheKey(const ImageCacheKey& aOther)
: mURI(aOther.mURI),
mBlobSerial(aOther.mBlobSerial),
mBlobRef(aOther.mBlobRef),
mOriginAttributes(aOther.mOriginAttributes),
mControlledDocument(aOther.mControlledDocument),
mTopLevelBaseDomain(aOther.mTopLevelBaseDomain),
mHash(aOther.mHash),
mIsChrome(aOther.mIsChrome) {}
ImageCacheKey::ImageCacheKey(ImageCacheKey&& aOther)
: mURI(std::move(aOther.mURI)),
mBlobSerial(std::move(aOther.mBlobSerial)),
mBlobRef(std::move(aOther.mBlobRef)),
mOriginAttributes(aOther.mOriginAttributes),
mControlledDocument(aOther.mControlledDocument),
mTopLevelBaseDomain(aOther.mTopLevelBaseDomain),
mHash(aOther.mHash),
mIsChrome(aOther.mIsChrome) {}
bool ImageCacheKey::operator==(const ImageCacheKey& aOther) const {
// Don't share the image cache between a controlled document and anything
// else.
if (mControlledDocument != aOther.mControlledDocument) {
return false;
}
// Don't share the image cache between two top-level documents of different
// base domains.
if (!mTopLevelBaseDomain.Equals(aOther.mTopLevelBaseDomain,
nsCaseInsensitiveCStringComparator())) {
return false;
}
// The origin attributes always have to match.
if (mOriginAttributes != aOther.mOriginAttributes) {
return false;
}
if (mBlobSerial || aOther.mBlobSerial) {
if (mBlobSerial && mBlobRef.IsEmpty()) {
EnsureBlobRef();
}
if (aOther.mBlobSerial && aOther.mBlobRef.IsEmpty()) {
aOther.EnsureBlobRef();
}
// If at least one of us has a blob serial, just compare the blob serial and
// the ref portion of the URIs.
return mBlobSerial == aOther.mBlobSerial && mBlobRef == aOther.mBlobRef;
}
// For non-blob URIs, compare the URIs.
bool equals = false;
nsresult rv = mURI->Equals(aOther.mURI, &equals);
return NS_SUCCEEDED(rv) && equals;
}
void ImageCacheKey::EnsureBlobRef() const {
MOZ_ASSERT(mBlobSerial);
MOZ_ASSERT(mBlobRef.IsEmpty());
nsresult rv = mURI->GetRef(mBlobRef);
NS_ENSURE_SUCCESS_VOID(rv);
}
void ImageCacheKey::EnsureHash() const {
MOZ_ASSERT(mHash.isNothing());
PLDHashNumber hash = 0;
// Since we frequently call Hash() several times in a row on the same
// ImageCacheKey, as an optimization we compute our hash once and store it.
nsPrintfCString ptr("%p", mControlledDocument);
nsAutoCString suffix;
mOriginAttributes.CreateSuffix(suffix);
if (mBlobSerial) {
if (mBlobRef.IsEmpty()) {
EnsureBlobRef();
}
hash = HashGeneric(*mBlobSerial, HashString(mBlobRef));
} else {
nsAutoCString spec;
Unused << mURI->GetSpec(spec);
hash = HashString(spec);
}
hash = AddToHash(hash, HashString(suffix), HashString(mTopLevelBaseDomain),
HashString(ptr));
mHash.emplace(hash);
}
/* static */
void* ImageCacheKey::GetSpecialCaseDocumentToken(Document* aDocument,
nsIURI* aURI) {
// Cookie-averse documents can never have storage granted to them. Since they
// may not have inner windows, they would require special handling below, so
// just bail out early here.
if (!aDocument || aDocument->IsCookieAverse()) {
return nullptr;
}
// For controlled documents, we cast the pointer into a void* to avoid
// dereferencing it (since we only use it for comparisons).
RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
if (swm && aDocument->GetController().isSome()) {
return aDocument;
}
return nullptr;
}
/* static */
nsCString ImageCacheKey::GetTopLevelBaseDomain(Document* aDocument,
nsIURI* aURI) {
if (!aDocument || !aDocument->GetInnerWindow()) {
return EmptyCString();
}
// If the window is 3rd party resource, let's see if first-party storage
// access is granted for this image.
if (nsContentUtils::IsThirdPartyTrackingResourceWindow(
aDocument->GetInnerWindow())) {
return StorageDisabledByAntiTracking(aDocument, aURI)
? aDocument->GetBaseDomain()
: EmptyCString();
}
// Another scenario is if this image is a 3rd party resource loaded by a
// first party context. In this case, we should check if the nsIChannel has
// been marked as tracking resource, but we don't have the channel yet at
// this point. The best approach here is to be conservative: if we are sure
// that the permission is granted, let's return 0. Otherwise, let's make a
// unique image cache per the top-level document eTLD+1.
if (!ContentBlocking::ApproximateAllowAccessForWithoutChannel(
aDocument->GetInnerWindow(), aURI)) {
nsPIDOMWindowOuter* top =
aDocument->GetInnerWindow()->GetInProcessScriptableTop();
nsPIDOMWindowInner* topInner = top ? top->GetCurrentInnerWindow() : nullptr;
if (!topInner) {
return aDocument
->GetBaseDomain(); // because we don't have anything better!
}
return topInner->GetExtantDoc() ? topInner->GetExtantDoc()->GetBaseDomain()
: EmptyCString();
}
return EmptyCString();
}
} // namespace image
} // namespace mozilla