Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1601 insertions, 0 deletions

diff --git a/dom/fetch/FetchDriver.cpp b/dom/fetch/FetchDriver.cpp
new file mode 100644
index 0000000000..31bc483d34
--- /dev/null
+++ b/dom/fetch/FetchDriver.cpp
@@ -0,0 +1,1601 @@
+/* -*- 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/dom/FetchDriver.h"
+
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "mozilla/dom/Document.h"
+#include "nsICookieJarSettings.h"
+#include "nsIFile.h"
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+#include "nsIFileChannel.h"
+#include "nsIHttpChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsISupportsPriority.h"
+#include "nsIThreadRetargetableRequest.h"
+#include "nsIUploadChannel2.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIPipe.h"
+
+#include "nsContentPolicyUtils.h"
+#include "nsDataHandler.h"
+#include "nsNetUtil.h"
+#include "nsPrintfCString.h"
+#include "nsProxyRelease.h"
+#include "nsStreamUtils.h"
+#include "nsStringStream.h"
+#include "nsHttpChannel.h"
+
+#include "mozilla/dom/BlobURLProtocolHandler.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/PerformanceStorage.h"
+#include "mozilla/dom/UserActivation.h"
+#include "mozilla/dom/WorkerCommon.h"
+#include "mozilla/PreloaderBase.h"
+#include "mozilla/net/NeckoChannelParams.h"
+#include "mozilla/ipc/PBackgroundSharedTypes.h"
+#include "mozilla/StaticPrefs_browser.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/StaticPrefs_privacy.h"
+#include "mozilla/Unused.h"
+
+#include "Fetch.h"
+#include "FetchUtil.h"
+#include "InternalRequest.h"
+#include "InternalResponse.h"
+
+namespace mozilla::dom {
+
+namespace {
+
+void GetBlobURISpecFromChannel(nsIRequest* aRequest, nsCString& aBlobURISpec) {
+  MOZ_ASSERT(aRequest);
+
+  aBlobURISpec.SetIsVoid(true);
+
+  nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
+  if (!channel) {
+    return;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = channel->GetURI(getter_AddRefs(uri));
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  if (!dom::IsBlobURI(uri)) {
+    return;
+  }
+
+  uri->GetSpec(aBlobURISpec);
+}
+
+bool ShouldCheckSRI(const InternalRequest& aRequest,
+                    const InternalResponse& aResponse) {
+  return !aRequest.GetIntegrity().IsEmpty() &&
+         aResponse.Type() != ResponseType::Error;
+}
+
+}  // anonymous namespace
+
+//-----------------------------------------------------------------------------
+// AlternativeDataStreamListener
+//-----------------------------------------------------------------------------
+class AlternativeDataStreamListener final
+    : public nsIStreamListener,
+      public nsIThreadRetargetableStreamListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
+
+  // The status of AlternativeDataStreamListener
+  // LOADING: is the initial status, loading the alternative data
+  // COMPLETED: Alternative data loading is completed
+  // CANCELED: Alternative data loading is canceled, this would make
+  //           AlternativeDataStreamListener ignore all channel callbacks
+  // FALLBACK: fallback the channel callbacks to FetchDriver
+  // Depends on different situaions, the status transition could be followings
+  // 1. LOADING->COMPLETED
+  //    This is the normal status transition for alternative data loading
+  //
+  // 2. LOADING->CANCELED
+  //    LOADING->COMPLETED->CANCELED
+  //    Alternative data loading could be canceled when cacheId from alternative
+  //    data channel does not match with from main data channel(The cacheID
+  //    checking is in FetchDriver::OnStartRequest).
+  //    Notice the alternative data loading could finish before the cacheID
+  //    checking, so the statust transition could be
+  //    LOADING->COMPLETED->CANCELED
+  //
+  // 3. LOADING->FALLBACK
+  //    For the case that alternative data loading could not be initialized,
+  //    i.e. alternative data does not exist or no preferred alternative data
+  //    type is requested. Once the status becomes FALLBACK,
+  //    AlternativeDataStreamListener transits the channel callback request to
+  //    FetchDriver, and the status should not go back to LOADING, COMPLETED, or
+  //    CANCELED anymore.
+  enum eStatus { LOADING = 0, COMPLETED, CANCELED, FALLBACK };
+
+  AlternativeDataStreamListener(FetchDriver* aFetchDriver, nsIChannel* aChannel,
+                                const nsACString& aAlternativeDataType);
+  eStatus Status();
+  void Cancel();
+  uint64_t GetAlternativeDataCacheEntryId();
+  const nsACString& GetAlternativeDataType() const;
+  already_AddRefed<nsICacheInfoChannel> GetCacheInfoChannel();
+  already_AddRefed<nsIInputStream> GetAlternativeInputStream();
+
+ private:
+  ~AlternativeDataStreamListener() = default;
+
+  // This creates a strong reference cycle with FetchDriver and its
+  // mAltDataListener. We need to clear at least one reference of them once the
+  // data loading finishes.
+  RefPtr<FetchDriver> mFetchDriver;
+  nsCString mAlternativeDataType;
+  nsCOMPtr<nsIInputStream> mPipeAlternativeInputStream;
+  nsCOMPtr<nsIOutputStream> mPipeAlternativeOutputStream;
+  uint64_t mAlternativeDataCacheEntryId;
+  nsCOMPtr<nsICacheInfoChannel> mCacheInfoChannel;
+  nsCOMPtr<nsIChannel> mChannel;
+  Atomic<eStatus> mStatus;
+};
+
+NS_IMPL_ISUPPORTS(AlternativeDataStreamListener, nsIStreamListener,
+                  nsIThreadRetargetableStreamListener)
+
+AlternativeDataStreamListener::AlternativeDataStreamListener(
+    FetchDriver* aFetchDriver, nsIChannel* aChannel,
+    const nsACString& aAlternativeDataType)
+    : mFetchDriver(aFetchDriver),
+      mAlternativeDataType(aAlternativeDataType),
+      mAlternativeDataCacheEntryId(0),
+      mChannel(aChannel),
+      mStatus(AlternativeDataStreamListener::LOADING) {
+  MOZ_DIAGNOSTIC_ASSERT(mFetchDriver);
+  MOZ_DIAGNOSTIC_ASSERT(mChannel);
+}
+
+AlternativeDataStreamListener::eStatus AlternativeDataStreamListener::Status() {
+  return mStatus;
+}
+
+void AlternativeDataStreamListener::Cancel() {
+  mAlternativeDataCacheEntryId = 0;
+  mCacheInfoChannel = nullptr;
+  mPipeAlternativeOutputStream = nullptr;
+  mPipeAlternativeInputStream = nullptr;
+  if (mChannel && mStatus != AlternativeDataStreamListener::FALLBACK) {
+    // if mStatus is fallback, we need to keep channel to forward request back
+    // to FetchDriver
+    mChannel->Cancel(NS_BINDING_ABORTED);
+    mChannel = nullptr;
+  }
+  mStatus = AlternativeDataStreamListener::CANCELED;
+}
+
+uint64_t AlternativeDataStreamListener::GetAlternativeDataCacheEntryId() {
+  return mAlternativeDataCacheEntryId;
+}
+
+const nsACString& AlternativeDataStreamListener::GetAlternativeDataType()
+    const {
+  return mAlternativeDataType;
+}
+
+already_AddRefed<nsIInputStream>
+AlternativeDataStreamListener::GetAlternativeInputStream() {
+  nsCOMPtr<nsIInputStream> inputStream = mPipeAlternativeInputStream;
+  return inputStream.forget();
+}
+
+already_AddRefed<nsICacheInfoChannel>
+AlternativeDataStreamListener::GetCacheInfoChannel() {
+  nsCOMPtr<nsICacheInfoChannel> channel = mCacheInfoChannel;
+  return channel.forget();
+}
+
+NS_IMETHODIMP
+AlternativeDataStreamListener::OnStartRequest(nsIRequest* aRequest) {
+  AssertIsOnMainThread();
+  MOZ_ASSERT(!mAlternativeDataType.IsEmpty());
+  // Checking the alternative data type is the same between we asked and the
+  // saved in the channel.
+  nsAutoCString alternativeDataType;
+  nsCOMPtr<nsICacheInfoChannel> cic = do_QueryInterface(aRequest);
+  mStatus = AlternativeDataStreamListener::LOADING;
+  if (cic && NS_SUCCEEDED(cic->GetAlternativeDataType(alternativeDataType)) &&
+      mAlternativeDataType.Equals(alternativeDataType) &&
+      NS_SUCCEEDED(cic->GetCacheEntryId(&mAlternativeDataCacheEntryId))) {
+    MOZ_DIAGNOSTIC_ASSERT(!mPipeAlternativeInputStream);
+    MOZ_DIAGNOSTIC_ASSERT(!mPipeAlternativeOutputStream);
+    nsresult rv =
+        NS_NewPipe(getter_AddRefs(mPipeAlternativeInputStream),
+                   getter_AddRefs(mPipeAlternativeOutputStream),
+                   0 /* default segment size */, UINT32_MAX /* infinite pipe */,
+                   true /* non-blocking input, otherwise you deadlock */,
+                   false /* blocking output, since the pipe is 'in'finite */);
+
+    if (NS_FAILED(rv)) {
+      mFetchDriver->FailWithNetworkError(rv);
+      return rv;
+    }
+
+    MOZ_DIAGNOSTIC_ASSERT(!mCacheInfoChannel);
+    mCacheInfoChannel = cic;
+
+    // call FetchDriver::HttpFetch to load main body
+    MOZ_ASSERT(mFetchDriver);
+    return mFetchDriver->HttpFetch();
+
+  } else {
+    // Needn't load alternative data, since alternative data does not exist.
+    // Set status to FALLBACK to reuse the opened channel to load main body,
+    // then call FetchDriver::OnStartRequest to continue the work. Unfortunately
+    // can't change the stream listener to mFetchDriver, need to keep
+    // AlternativeDataStreamListener alive to redirect OnDataAvailable and
+    // OnStopRequest to mFetchDriver.
+    MOZ_ASSERT(alternativeDataType.IsEmpty());
+    mStatus = AlternativeDataStreamListener::FALLBACK;
+    mAlternativeDataCacheEntryId = 0;
+    MOZ_ASSERT(mFetchDriver);
+    return mFetchDriver->OnStartRequest(aRequest);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AlternativeDataStreamListener::OnDataAvailable(nsIRequest* aRequest,
+                                               nsIInputStream* aInputStream,
+                                               uint64_t aOffset,
+                                               uint32_t aCount) {
+  if (mStatus == AlternativeDataStreamListener::LOADING) {
+    MOZ_ASSERT(mPipeAlternativeOutputStream);
+    uint32_t read = 0;
+    return aInputStream->ReadSegments(
+        NS_CopySegmentToStream, mPipeAlternativeOutputStream, aCount, &read);
+  }
+  if (mStatus == AlternativeDataStreamListener::FALLBACK) {
+    MOZ_ASSERT(mFetchDriver);
+    return mFetchDriver->OnDataAvailable(aRequest, aInputStream, aOffset,
+                                         aCount);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AlternativeDataStreamListener::OnStopRequest(nsIRequest* aRequest,
+                                             nsresult aStatusCode) {
+  AssertIsOnMainThread();
+
+  // Alternative data loading is going to finish, breaking the reference cycle
+  // here by taking the ownership to a loacl variable.
+  RefPtr<FetchDriver> fetchDriver = std::move(mFetchDriver);
+
+  if (mStatus == AlternativeDataStreamListener::CANCELED) {
+    // do nothing
+    return NS_OK;
+  }
+
+  if (mStatus == AlternativeDataStreamListener::FALLBACK) {
+    MOZ_ASSERT(fetchDriver);
+    return fetchDriver->OnStopRequest(aRequest, aStatusCode);
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(mStatus == AlternativeDataStreamListener::LOADING);
+
+  MOZ_ASSERT(!mAlternativeDataType.IsEmpty() && mPipeAlternativeOutputStream &&
+             mPipeAlternativeInputStream);
+
+  mPipeAlternativeOutputStream->Close();
+  mPipeAlternativeOutputStream = nullptr;
+
+  // Cleanup the states for alternative data if needed.
+  if (NS_FAILED(aStatusCode)) {
+    mAlternativeDataCacheEntryId = 0;
+    mCacheInfoChannel = nullptr;
+    mPipeAlternativeInputStream = nullptr;
+  }
+  mStatus = AlternativeDataStreamListener::COMPLETED;
+  // alternative data loading finish, call FetchDriver::FinishOnStopRequest to
+  // continue the final step for the case FetchDriver::OnStopRequest is called
+  // earlier than AlternativeDataStreamListener::OnStopRequest
+  MOZ_ASSERT(fetchDriver);
+  fetchDriver->FinishOnStopRequest(this);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AlternativeDataStreamListener::CheckListenerChain() { return NS_OK; }
+//-----------------------------------------------------------------------------
+// FetchDriver
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(FetchDriver, nsIStreamListener, nsIChannelEventSink,
+                  nsIInterfaceRequestor, nsIThreadRetargetableStreamListener)
+
+FetchDriver::FetchDriver(SafeRefPtr<InternalRequest> aRequest,
+                         nsIPrincipal* aPrincipal, nsILoadGroup* aLoadGroup,
+                         nsIEventTarget* aMainThreadEventTarget,
+                         nsICookieJarSettings* aCookieJarSettings,
+                         PerformanceStorage* aPerformanceStorage,
+                         bool aIsTrackingFetch)
+    : mPrincipal(aPrincipal),
+      mLoadGroup(aLoadGroup),
+      mRequest(std::move(aRequest)),
+      mMainThreadEventTarget(aMainThreadEventTarget),
+      mCookieJarSettings(aCookieJarSettings),
+      mPerformanceStorage(aPerformanceStorage),
+      mNeedToObserveOnDataAvailable(false),
+      mIsTrackingFetch(aIsTrackingFetch),
+      mOnStopRequestCalled(false)
+#ifdef DEBUG
+      ,
+      mResponseAvailableCalled(false),
+      mFetchCalled(false)
+#endif
+{
+  AssertIsOnMainThread();
+
+  MOZ_ASSERT(mRequest);
+  MOZ_ASSERT(aPrincipal);
+  MOZ_ASSERT(aMainThreadEventTarget);
+}
+
+FetchDriver::~FetchDriver() {
+  AssertIsOnMainThread();
+
+  // We assert this since even on failures, we should call
+  // FailWithNetworkError().
+  MOZ_ASSERT(mResponseAvailableCalled);
+}
+
+already_AddRefed<PreloaderBase> FetchDriver::FindPreload(nsIURI* aURI) {
+  // Decide if we allow reuse of an existing <link rel=preload as=fetch>
+  // response for this request.  First examine this fetch requets itself if it
+  // is 'pure' enough to use the response and then try to find a preload.
+
+  if (!mDocument) {
+    // Preloads are mapped on the document, no document, no preload.
+    return nullptr;
+  }
+  CORSMode cors;
+  switch (mRequest->Mode()) {
+    case RequestMode::No_cors:
+      cors = CORSMode::CORS_NONE;
+      break;
+    case RequestMode::Cors:
+      cors = mRequest->GetCredentialsMode() == RequestCredentials::Include
+                 ? CORSMode::CORS_USE_CREDENTIALS
+                 : CORSMode::CORS_ANONYMOUS;
+      break;
+    default:
+      // Can't be satisfied by a preload because preload cannot define any of
+      // remaining modes.
+      return nullptr;
+  }
+  if (!mRequest->Headers()->HasOnlySimpleHeaders()) {
+    // Preload can't set any headers.
+    return nullptr;
+  }
+  if (!mRequest->GetIntegrity().IsEmpty()) {
+    // There is currently no support for SRI checking in the fetch preloader.
+    return nullptr;
+  }
+  if (mRequest->GetCacheMode() != RequestCache::Default) {
+    // Preload can only go with the default caching mode.
+    return nullptr;
+  }
+  if (mRequest->SkipServiceWorker()) {
+    // Preload can't be forbidden interception.
+    return nullptr;
+  }
+  if (mRequest->GetRedirectMode() != RequestRedirect::Follow) {
+    // Preload always follows redirects.
+    return nullptr;
+  }
+  nsAutoCString method;
+  mRequest->GetMethod(method);
+  if (!method.EqualsLiteral("GET")) {
+    // Preload can only do GET, this also eliminates the case we do upload, so
+    // no need to check if the request has any body to send out.
+    return nullptr;
+  }
+
+  // OK, this request can be satisfied by a preloaded response, try to find one.
+
+  auto preloadKey = PreloadHashKey::CreateAsFetch(aURI, cors);
+  return mDocument->Preloads().LookupPreload(preloadKey);
+}
+
+void FetchDriver::UpdateReferrerInfoFromNewChannel(nsIChannel* aChannel) {
+  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aChannel);
+  if (!httpChannel) {
+    return;
+  }
+
+  nsCOMPtr<nsIReferrerInfo> referrerInfo = httpChannel->GetReferrerInfo();
+  if (!referrerInfo) {
+    return;
+  }
+
+  nsAutoString computedReferrerSpec;
+  mRequest->SetReferrerPolicy(referrerInfo->ReferrerPolicy());
+  Unused << referrerInfo->GetComputedReferrerSpec(computedReferrerSpec);
+  mRequest->SetReferrer(computedReferrerSpec);
+}
+
+nsresult FetchDriver::Fetch(AbortSignalImpl* aSignalImpl,
+                            FetchDriverObserver* aObserver) {
+  AssertIsOnMainThread();
+#ifdef DEBUG
+  MOZ_ASSERT(!mFetchCalled);
+  mFetchCalled = true;
+#endif
+
+  mObserver = aObserver;
+
+  // FIXME(nsm): Deal with HSTS.
+
+  MOZ_RELEASE_ASSERT(!mRequest->IsSynchronous(),
+                     "Synchronous fetch not supported");
+
+  UniquePtr<mozilla::ipc::PrincipalInfo> principalInfo(
+      new mozilla::ipc::PrincipalInfo());
+  nsresult rv = PrincipalToPrincipalInfo(mPrincipal, principalInfo.get());
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  mRequest->SetPrincipalInfo(std::move(principalInfo));
+
+  // If the signal is aborted, it's time to inform the observer and terminate
+  // the operation.
+  if (aSignalImpl) {
+    if (aSignalImpl->Aborted()) {
+      RunAbortAlgorithm();
+      return NS_OK;
+    }
+
+    Follow(aSignalImpl);
+  }
+
+  rv = HttpFetch(mRequest->GetPreferredAlternativeDataType());
+  if (NS_FAILED(rv)) {
+    FailWithNetworkError(rv);
+  }
+
+  // Any failure is handled by FailWithNetworkError notifying the aObserver.
+  return NS_OK;
+}
+
+// This function implements the "HTTP Fetch" algorithm from the Fetch spec.
+// Functionality is often split between here, the CORS listener proxy and the
+// Necko HTTP implementation.
+nsresult FetchDriver::HttpFetch(
+    const nsACString& aPreferredAlternativeDataType) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // Step 1. "Let response be null."
+  mResponse = nullptr;
+  mOnStopRequestCalled = false;
+  nsresult rv;
+
+  nsCOMPtr<nsIIOService> ios = do_GetIOService(&rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString url;
+  mRequest->GetURL(url);
+  nsCOMPtr<nsIURI> uri;
+  rv = NS_NewURI(getter_AddRefs(uri), url);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Unsafe requests aren't allowed with when using no-core mode.
+  if (mRequest->Mode() == RequestMode::No_cors && mRequest->UnsafeRequest() &&
+      (!mRequest->HasSimpleMethod() ||
+       !mRequest->Headers()->HasOnlySimpleHeaders())) {
+    MOZ_ASSERT(false, "The API should have caught this");
+    return NS_ERROR_DOM_BAD_URI;
+  }
+
+  // non-GET requests aren't allowed for blob.
+  if (IsBlobURI(uri)) {
+    nsAutoCString method;
+    mRequest->GetMethod(method);
+    if (!method.EqualsLiteral("GET")) {
+      return NS_ERROR_DOM_NETWORK_ERR;
+    }
+  }
+
+  RefPtr<PreloaderBase> fetchPreload = FindPreload(uri);
+  if (fetchPreload) {
+    fetchPreload->RemoveSelf(mDocument);
+    fetchPreload->NotifyUsage(PreloaderBase::LoadBackground::Keep);
+
+    rv = fetchPreload->AsyncConsume(this);
+    if (NS_SUCCEEDED(rv)) {
+      mFromPreload = true;
+
+      mChannel = fetchPreload->Channel();
+      MOZ_ASSERT(mChannel);
+      mChannel->SetNotificationCallbacks(this);
+
+      // Copied from AsyncOnChannelRedirect.
+      for (const auto& redirect : fetchPreload->Redirects()) {
+        if (redirect.Flags() & nsIChannelEventSink::REDIRECT_INTERNAL) {
+          mRequest->SetURLForInternalRedirect(redirect.Flags(), redirect.Spec(),
+                                              redirect.Fragment());
+        } else {
+          mRequest->AddURL(redirect.Spec(), redirect.Fragment());
+        }
+      }
+
+      return NS_OK;
+    }
+
+    // The preload failed to be consumed.  Behave like there were no preload.
+    fetchPreload = nullptr;
+  }
+
+  // Step 2 deals with letting ServiceWorkers intercept requests. This is
+  // handled by Necko after the channel is opened.
+  // FIXME(nsm): Bug 1119026: The channel's skip service worker flag should be
+  // set based on the Request's flag.
+
+  // Step 3.1 "If the CORS preflight flag is set and one of these conditions is
+  // true..." is handled by the CORS proxy.
+  //
+  // Step 3.2 "Set request's skip service worker flag." This isn't required
+  // since Necko will fall back to the network if the ServiceWorker does not
+  // respond with a valid Response.
+  //
+  // NS_StartCORSPreflight() will automatically kick off the original request
+  // if it succeeds, so we need to have everything setup for the original
+  // request too.
+
+  // Step 3.3 "Let credentials flag be set if one of
+  //  - request's credentials mode is "include"
+  //  - request's credentials mode is "same-origin" and either the CORS flag
+  //    is unset or response tainting is "opaque"
+  // is true, and unset otherwise."
+
+  // Set skip serviceworker flag.
+  // While the spec also gates on the client being a ServiceWorker, we can't
+  // infer that here. Instead we rely on callers to set the flag correctly.
+  const nsLoadFlags bypassFlag = mRequest->SkipServiceWorker()
+                                     ? nsIChannel::LOAD_BYPASS_SERVICE_WORKER
+                                     : 0;
+
+  nsSecurityFlags secFlags = 0;
+  if (mRequest->Mode() == RequestMode::Cors) {
+    secFlags |= nsILoadInfo::SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT;
+  } else if (mRequest->Mode() == RequestMode::Same_origin ||
+             mRequest->Mode() == RequestMode::Navigate) {
+    secFlags |= nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_INHERITS_SEC_CONTEXT;
+  } else if (mRequest->Mode() == RequestMode::No_cors) {
+    secFlags |= nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_INHERITS_SEC_CONTEXT;
+  } else {
+    MOZ_ASSERT_UNREACHABLE("Unexpected request mode!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (mRequest->GetRedirectMode() != RequestRedirect::Follow) {
+    secFlags |= nsILoadInfo::SEC_DONT_FOLLOW_REDIRECTS;
+  }
+
+  // This is handles the use credentials flag in "HTTP
+  // network or cache fetch" in the spec and decides whether to transmit
+  // cookies and other identifying information.
+  if (mRequest->GetCredentialsMode() == RequestCredentials::Include) {
+    secFlags |= nsILoadInfo::SEC_COOKIES_INCLUDE;
+  } else if (mRequest->GetCredentialsMode() == RequestCredentials::Omit) {
+    secFlags |= nsILoadInfo::SEC_COOKIES_OMIT;
+  } else if (mRequest->GetCredentialsMode() ==
+             RequestCredentials::Same_origin) {
+    secFlags |= nsILoadInfo::SEC_COOKIES_SAME_ORIGIN;
+  } else {
+    MOZ_ASSERT_UNREACHABLE("Unexpected credentials mode!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // From here on we create a channel and set its properties with the
+  // information from the InternalRequest. This is an implementation detail.
+  MOZ_ASSERT(mLoadGroup);
+  nsCOMPtr<nsIChannel> chan;
+
+  nsLoadFlags loadFlags = nsIRequest::LOAD_BACKGROUND | bypassFlag;
+  if (mDocument) {
+    MOZ_ASSERT(mDocument->NodePrincipal() == mPrincipal);
+    MOZ_ASSERT(mDocument->CookieJarSettings() == mCookieJarSettings);
+    rv = NS_NewChannel(getter_AddRefs(chan), uri, mDocument, secFlags,
+                       mRequest->ContentPolicyType(),
+                       nullptr,             /* aPerformanceStorage */
+                       mLoadGroup, nullptr, /* aCallbacks */
+                       loadFlags, ios);
+  } else if (mClientInfo.isSome()) {
+    rv = NS_NewChannel(getter_AddRefs(chan), uri, mPrincipal, mClientInfo.ref(),
+                       mController, secFlags, mRequest->ContentPolicyType(),
+                       mCookieJarSettings, mPerformanceStorage, mLoadGroup,
+                       nullptr, /* aCallbacks */
+                       loadFlags, ios);
+  } else {
+    rv =
+        NS_NewChannel(getter_AddRefs(chan), uri, mPrincipal, secFlags,
+                      mRequest->ContentPolicyType(), mCookieJarSettings,
+                      mPerformanceStorage, mLoadGroup, nullptr, /* aCallbacks */
+                      loadFlags, ios);
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mCSPEventListener) {
+    nsCOMPtr<nsILoadInfo> loadInfo = chan->LoadInfo();
+    rv = loadInfo->SetCspEventListener(mCSPEventListener);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  {
+    nsCOMPtr<nsILoadInfo> loadInfo = chan->LoadInfo();
+    rv = loadInfo->SetLoadingEmbedderPolicy(mRequest->GetEmbedderPolicy());
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // Insert ourselves into the notification callbacks chain so we can set
+  // headers on redirects.
+#ifdef DEBUG
+  {
+    nsCOMPtr<nsIInterfaceRequestor> notificationCallbacks;
+    chan->GetNotificationCallbacks(getter_AddRefs(notificationCallbacks));
+    MOZ_ASSERT(!notificationCallbacks);
+  }
+#endif
+  chan->SetNotificationCallbacks(this);
+
+  nsCOMPtr<nsIClassOfService> cos(do_QueryInterface(chan));
+  // Mark channel as urgent-start if the Fetch is triggered by user input
+  // events.
+  if (cos && UserActivation::IsHandlingUserInput()) {
+    cos->AddClassFlags(nsIClassOfService::UrgentStart);
+  }
+
+  // Step 3.5 begins "HTTP network or cache fetch".
+  // HTTP network or cache fetch
+  // ---------------------------
+  // Step 1 "Let HTTPRequest..." The channel is the HTTPRequest.
+  nsCOMPtr<nsIHttpChannel> httpChan = do_QueryInterface(chan);
+  if (httpChan) {
+    // Copy the method.
+    nsAutoCString method;
+    mRequest->GetMethod(method);
+    rv = httpChan->SetRequestMethod(method);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Set the same headers.
+    SetRequestHeaders(httpChan, false);
+
+    // Step 5 of https://fetch.spec.whatwg.org/#main-fetch
+    // If request's referrer policy is the empty string and request's client is
+    // non-null, then set request's referrer policy to request's client's
+    // associated referrer policy.
+    // Basically, "client" is not in our implementation, we use
+    // EnvironmentReferrerPolicy of the worker or document context
+    ReferrerPolicy referrerPolicy = mRequest->GetEnvironmentReferrerPolicy();
+    if (mRequest->ReferrerPolicy_() == ReferrerPolicy::_empty) {
+      mRequest->SetReferrerPolicy(referrerPolicy);
+    }
+    // Step 6 of https://fetch.spec.whatwg.org/#main-fetch
+    // If request’s referrer policy is the empty string,
+    // then set request’s referrer policy to the user-set default policy.
+    if (mRequest->ReferrerPolicy_() == ReferrerPolicy::_empty) {
+      nsCOMPtr<nsILoadInfo> loadInfo = httpChan->LoadInfo();
+      bool isPrivate = loadInfo->GetOriginAttributes().mPrivateBrowsingId > 0;
+      referrerPolicy =
+          ReferrerInfo::GetDefaultReferrerPolicy(httpChan, uri, isPrivate);
+      mRequest->SetReferrerPolicy(referrerPolicy);
+    }
+
+    rv = FetchUtil::SetRequestReferrer(mPrincipal, mDocument, httpChan,
+                                       *mRequest);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Bug 1120722 - Authorization will be handled later.
+    // Auth may require prompting, we don't support it yet.
+    // The next patch in this same bug prevents this from aborting the request.
+    // Credentials checks for CORS are handled by nsCORSListenerProxy,
+
+    nsCOMPtr<nsIHttpChannelInternal> internalChan = do_QueryInterface(httpChan);
+
+    // Conversion between enumerations is safe due to static asserts in
+    // dom/workers/ServiceWorkerManager.cpp
+    rv = internalChan->SetCorsMode(static_cast<uint32_t>(mRequest->Mode()));
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    rv = internalChan->SetRedirectMode(
+        static_cast<uint32_t>(mRequest->GetRedirectMode()));
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    mRequest->MaybeSkipCacheIfPerformingRevalidation();
+    rv = internalChan->SetFetchCacheMode(
+        static_cast<uint32_t>(mRequest->GetCacheMode()));
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    rv = internalChan->SetIntegrityMetadata(mRequest->GetIntegrity());
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    // Set the initiator type
+    nsCOMPtr<nsITimedChannel> timedChannel(do_QueryInterface(httpChan));
+    if (timedChannel) {
+      timedChannel->SetInitiatorType(u"fetch"_ns);
+    }
+  }
+
+  // Step 5. Proxy authentication will be handled by Necko.
+
+  // Continue setting up 'HTTPRequest'. Content-Type and body data.
+  nsCOMPtr<nsIUploadChannel2> uploadChan = do_QueryInterface(chan);
+  if (uploadChan) {
+    nsAutoCString contentType;
+    ErrorResult result;
+    mRequest->Headers()->GetFirst("content-type"_ns, contentType, result);
+    // We don't actually expect "result" to have failed here: that only happens
+    // for invalid header names.  But if for some reason it did, just propagate
+    // it out.
+    if (result.Failed()) {
+      return result.StealNSResult();
+    }
+
+    // Now contentType is the header that was set in mRequest->Headers(), or a
+    // void string if no header was set.
+#ifdef DEBUG
+    bool hasContentTypeHeader =
+        mRequest->Headers()->Has("content-type"_ns, result);
+    MOZ_ASSERT(!result.Failed());
+    MOZ_ASSERT_IF(!hasContentTypeHeader, contentType.IsVoid());
+#endif  // DEBUG
+
+    int64_t bodyLength;
+    nsCOMPtr<nsIInputStream> bodyStream;
+    mRequest->GetBody(getter_AddRefs(bodyStream), &bodyLength);
+    if (bodyStream) {
+      nsAutoCString method;
+      mRequest->GetMethod(method);
+      rv = uploadChan->ExplicitSetUploadStream(bodyStream, contentType,
+                                               bodyLength, method,
+                                               false /* aStreamHasHeaders */);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  // If preflight is required, start a "CORS preflight fetch"
+  // https://fetch.spec.whatwg.org/#cors-preflight-fetch-0. All the
+  // implementation is handled by the http channel calling into
+  // nsCORSListenerProxy. We just inform it which unsafe headers are included
+  // in the request.
+  if (mRequest->Mode() == RequestMode::Cors) {
+    AutoTArray<nsCString, 5> unsafeHeaders;
+    mRequest->Headers()->GetUnsafeHeaders(unsafeHeaders);
+    nsCOMPtr<nsILoadInfo> loadInfo = chan->LoadInfo();
+    loadInfo->SetCorsPreflightInfo(unsafeHeaders, false);
+  }
+
+  if (mIsTrackingFetch && StaticPrefs::network_http_tailing_enabled() && cos) {
+    cos->AddClassFlags(nsIClassOfService::Throttleable |
+                       nsIClassOfService::Tail);
+  }
+
+  if (mIsTrackingFetch &&
+      StaticPrefs::privacy_trackingprotection_lower_network_priority()) {
+    nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(chan);
+    if (p) {
+      p->SetPriority(nsISupportsPriority::PRIORITY_LOWEST);
+    }
+  }
+
+  NotifyNetworkMonitorAlternateStack(chan, std::move(mOriginStack));
+
+  // if the preferred alternative data type in InternalRequest is not empty, set
+  // the data type on the created channel and also create a
+  // AlternativeDataStreamListener to be the stream listener of the channel.
+  if (!aPreferredAlternativeDataType.IsEmpty()) {
+    nsCOMPtr<nsICacheInfoChannel> cic = do_QueryInterface(chan);
+    if (cic) {
+      cic->PreferAlternativeDataType(aPreferredAlternativeDataType, ""_ns,
+                                     true);
+      MOZ_ASSERT(!mAltDataListener);
+      mAltDataListener = new AlternativeDataStreamListener(
+          this, chan, aPreferredAlternativeDataType);
+      rv = chan->AsyncOpen(mAltDataListener);
+    } else {
+      rv = chan->AsyncOpen(this);
+    }
+  } else {
+    // Integrity check cannot be done on alt-data yet.
+    if (mRequest->GetIntegrity().IsEmpty()) {
+      nsCOMPtr<nsICacheInfoChannel> cic = do_QueryInterface(chan);
+      if (cic) {
+        cic->PreferAlternativeDataType(nsLiteralCString(WASM_ALT_DATA_TYPE_V1),
+                                       nsLiteralCString(WASM_CONTENT_TYPE),
+                                       false);
+      }
+    }
+
+    rv = chan->AsyncOpen(this);
+  }
+
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Step 4 onwards of "HTTP Fetch" is handled internally by Necko.
+
+  mChannel = chan;
+  return NS_OK;
+}
+already_AddRefed<InternalResponse> FetchDriver::BeginAndGetFilteredResponse(
+    InternalResponse* aResponse, bool aFoundOpaqueRedirect) {
+  MOZ_ASSERT(aResponse);
+  AutoTArray<nsCString, 4> reqURLList;
+  mRequest->GetURLListWithoutFragment(reqURLList);
+  MOZ_ASSERT(!reqURLList.IsEmpty());
+  aResponse->SetURLList(reqURLList);
+  RefPtr<InternalResponse> filteredResponse;
+  if (aFoundOpaqueRedirect) {
+    filteredResponse = aResponse->OpaqueRedirectResponse();
+  } else {
+    switch (mRequest->GetResponseTainting()) {
+      case LoadTainting::Basic:
+        filteredResponse = aResponse->BasicResponse();
+        break;
+      case LoadTainting::CORS:
+        filteredResponse = aResponse->CORSResponse();
+        break;
+      case LoadTainting::Opaque: {
+        filteredResponse = aResponse->OpaqueResponse();
+        nsresult rv = filteredResponse->GeneratePaddingInfo();
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return nullptr;
+        }
+        break;
+      }
+      default:
+        MOZ_CRASH("Unexpected case");
+    }
+  }
+
+  MOZ_ASSERT(filteredResponse);
+  MOZ_ASSERT(mObserver);
+  if (!ShouldCheckSRI(*mRequest, *filteredResponse)) {
+    // Need to keep mObserver alive.
+    RefPtr<FetchDriverObserver> observer = mObserver;
+    observer->OnResponseAvailable(filteredResponse);
+#ifdef DEBUG
+    mResponseAvailableCalled = true;
+#endif
+  }
+
+  return filteredResponse.forget();
+}
+
+void FetchDriver::FailWithNetworkError(nsresult rv) {
+  AssertIsOnMainThread();
+  RefPtr<InternalResponse> error = InternalResponse::NetworkError(rv);
+  if (mObserver) {
+    // Need to keep mObserver alive.
+    RefPtr<FetchDriverObserver> observer = mObserver;
+    observer->OnResponseAvailable(error);
+#ifdef DEBUG
+    mResponseAvailableCalled = true;
+#endif
+  }
+
+  // mObserver could be null after OnResponseAvailable().
+  if (mObserver) {
+    mObserver->OnResponseEnd(FetchDriverObserver::eByNetworking);
+    mObserver = nullptr;
+  }
+
+  mChannel = nullptr;
+}
+
+NS_IMETHODIMP
+FetchDriver::OnStartRequest(nsIRequest* aRequest) {
+  AssertIsOnMainThread();
+
+  // Note, this can be called multiple times if we are doing an opaqueredirect.
+  // In that case we will get a simulated OnStartRequest() and then the real
+  // channel will call in with an errored OnStartRequest().
+
+  if (mFromPreload && mAborted) {
+    aRequest->Cancel(NS_BINDING_ABORTED);
+    return NS_BINDING_ABORTED;
+  }
+
+  if (!mChannel) {
+    MOZ_ASSERT(!mObserver);
+    return NS_BINDING_ABORTED;
+  }
+
+  nsresult rv;
+  aRequest->GetStatus(&rv);
+  if (NS_FAILED(rv)) {
+    FailWithNetworkError(rv);
+    return rv;
+  }
+
+  // We should only get to the following code once.
+  MOZ_ASSERT(!mPipeOutputStream);
+
+  if (!mObserver) {
+    MOZ_ASSERT(false, "We should have mObserver here.");
+    FailWithNetworkError(NS_ERROR_UNEXPECTED);
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  mNeedToObserveOnDataAvailable = mObserver->NeedOnDataAvailable();
+
+  RefPtr<InternalResponse> response;
+  nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
+  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aRequest);
+
+  // On a successful redirect we perform the following substeps of HTTP Fetch,
+  // step 5, "redirect status", step 11.
+
+  bool foundOpaqueRedirect = false;
+
+  nsAutoCString contentType;
+  channel->GetContentType(contentType);
+
+  int64_t contentLength = InternalResponse::UNKNOWN_BODY_SIZE;
+  rv = channel->GetContentLength(&contentLength);
+  MOZ_ASSERT_IF(NS_FAILED(rv),
+                contentLength == InternalResponse::UNKNOWN_BODY_SIZE);
+
+  if (httpChannel) {
+    uint32_t responseStatus;
+    rv = httpChannel->GetResponseStatus(&responseStatus);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    if (mozilla::net::nsHttpChannel::IsRedirectStatus(responseStatus)) {
+      if (mRequest->GetRedirectMode() == RequestRedirect::Error) {
+        FailWithNetworkError(NS_BINDING_ABORTED);
+        return NS_BINDING_FAILED;
+      }
+      if (mRequest->GetRedirectMode() == RequestRedirect::Manual) {
+        foundOpaqueRedirect = true;
+      }
+    }
+
+    nsAutoCString statusText;
+    rv = httpChannel->GetResponseStatusText(statusText);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    response = new InternalResponse(responseStatus, statusText,
+                                    mRequest->GetCredentialsMode());
+
+    UniquePtr<mozilla::ipc::PrincipalInfo> principalInfo(
+        new mozilla::ipc::PrincipalInfo());
+    nsresult rv = PrincipalToPrincipalInfo(mPrincipal, principalInfo.get());
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    response->SetPrincipalInfo(std::move(principalInfo));
+
+    response->Headers()->FillResponseHeaders(httpChannel);
+
+    // If Content-Encoding or Transfer-Encoding headers are set, then the actual
+    // Content-Length (which refer to the decoded data) is obscured behind the
+    // encodings.
+    ErrorResult result;
+    if (response->Headers()->Has("content-encoding"_ns, result) ||
+        response->Headers()->Has("transfer-encoding"_ns, result)) {
+      // We cannot trust the content-length when content-encoding or
+      // transfer-encoding are set.  There are many servers which just
+      // get this wrong.
+      contentLength = InternalResponse::UNKNOWN_BODY_SIZE;
+    }
+    MOZ_ASSERT(!result.Failed());
+  } else {
+    response =
+        new InternalResponse(200, "OK"_ns, mRequest->GetCredentialsMode());
+
+    if (!contentType.IsEmpty()) {
+      nsAutoCString contentCharset;
+      channel->GetContentCharset(contentCharset);
+      if (NS_SUCCEEDED(rv) && !contentCharset.IsEmpty()) {
+        contentType += ";charset="_ns + contentCharset;
+      }
+
+      IgnoredErrorResult result;
+      response->Headers()->Append("Content-Type"_ns, contentType, result);
+      MOZ_ASSERT(!result.Failed());
+    }
+
+    if (contentLength > 0) {
+      nsAutoCString contentLenStr;
+      contentLenStr.AppendInt(contentLength);
+
+      IgnoredErrorResult result;
+      response->Headers()->Append("Content-Length"_ns, contentLenStr, result);
+      MOZ_ASSERT(!result.Failed());
+    }
+  }
+
+  nsCOMPtr<nsICacheInfoChannel> cic = do_QueryInterface(aRequest);
+  if (cic) {
+    if (mAltDataListener) {
+      // Skip the case that mAltDataListener->Status() equals to FALLBACK, that
+      // means the opened channel for alternative data loading is reused for
+      // loading the main data.
+      if (mAltDataListener->Status() !=
+          AlternativeDataStreamListener::FALLBACK) {
+        // Verify the cache ID is the same with from alternative data cache.
+        // If the cache ID is different, droping the alternative data loading,
+        // otherwise setup the response's alternative body and cacheInfoChannel.
+        uint64_t cacheEntryId = 0;
+        if (NS_SUCCEEDED(cic->GetCacheEntryId(&cacheEntryId)) &&
+            cacheEntryId !=
+                mAltDataListener->GetAlternativeDataCacheEntryId()) {
+          mAltDataListener->Cancel();
+        } else {
+          // AlternativeDataStreamListener::OnStartRequest had already been
+          // called, the alternative data input stream and cacheInfo channel
+          // must be created.
+          nsCOMPtr<nsICacheInfoChannel> cacheInfo =
+              mAltDataListener->GetCacheInfoChannel();
+          nsCOMPtr<nsIInputStream> altInputStream =
+              mAltDataListener->GetAlternativeInputStream();
+          MOZ_ASSERT(altInputStream && cacheInfo);
+          response->SetAlternativeBody(altInputStream);
+          nsMainThreadPtrHandle<nsICacheInfoChannel> handle(
+              new nsMainThreadPtrHolder<nsICacheInfoChannel>(
+                  "nsICacheInfoChannel", cacheInfo, false));
+          response->SetCacheInfoChannel(handle);
+        }
+      } else if (!mAltDataListener->GetAlternativeDataType().IsEmpty()) {
+        // If the status is FALLBACK and the
+        // mAltDataListener::mAlternativeDataType is not empty, that means the
+        // data need to be saved into cache, setup the response's
+        // nsICacheInfoChannel for caching the data after loading.
+        nsMainThreadPtrHandle<nsICacheInfoChannel> handle(
+            new nsMainThreadPtrHolder<nsICacheInfoChannel>(
+                "nsICacheInfoChannel", cic, false));
+        response->SetCacheInfoChannel(handle);
+      }
+    } else if (!cic->PreferredAlternativeDataTypes().IsEmpty()) {
+      MOZ_ASSERT(cic->PreferredAlternativeDataTypes().Length() == 1);
+      MOZ_ASSERT(cic->PreferredAlternativeDataTypes()[0].type().EqualsLiteral(
+          WASM_ALT_DATA_TYPE_V1));
+      MOZ_ASSERT(
+          cic->PreferredAlternativeDataTypes()[0].contentType().EqualsLiteral(
+              WASM_CONTENT_TYPE));
+
+      if (contentType.EqualsLiteral(WASM_CONTENT_TYPE)) {
+        // We want to attach the CacheInfoChannel to the response object such
+        // that we can track its origin when the Response object is manipulated
+        // by JavaScript code. This is important for WebAssembly, which uses
+        // fetch to query its sources in JavaScript and transfer the Response
+        // object to other function responsible for storing the alternate data
+        // using the CacheInfoChannel.
+        nsMainThreadPtrHandle<nsICacheInfoChannel> handle(
+            new nsMainThreadPtrHolder<nsICacheInfoChannel>(
+                "nsICacheInfoChannel", cic, false));
+        response->SetCacheInfoChannel(handle);
+      }
+    }
+  }
+
+  // We open a pipe so that we can immediately set the pipe's read end as the
+  // response's body. Setting the segment size to UINT32_MAX means that the
+  // pipe has infinite space. The nsIChannel will continue to buffer data in
+  // xpcom events even if we block on a fixed size pipe.  It might be possible
+  // to suspend the channel and then resume when there is space available, but
+  // for now use an infinite pipe to avoid blocking.
+  nsCOMPtr<nsIInputStream> pipeInputStream;
+  rv = NS_NewPipe(getter_AddRefs(pipeInputStream),
+                  getter_AddRefs(mPipeOutputStream),
+                  0, /* default segment size */
+                  UINT32_MAX /* infinite pipe */,
+                  true /* non-blocking input, otherwise you deadlock */,
+                  false /* blocking output, since the pipe is 'in'finite */);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    FailWithNetworkError(rv);
+    // Cancel request.
+    return rv;
+  }
+  response->SetBody(pipeInputStream, contentLength);
+
+  // If the request is a file channel, then remember the local path to
+  // that file so we can later create File blobs rather than plain ones.
+  nsCOMPtr<nsIFileChannel> fc = do_QueryInterface(aRequest);
+  if (fc) {
+    nsCOMPtr<nsIFile> file;
+    rv = fc->GetFile(getter_AddRefs(file));
+    if (!NS_WARN_IF(NS_FAILED(rv))) {
+      nsAutoString path;
+      file->GetPath(path);
+      response->SetBodyLocalPath(path);
+    }
+  } else {
+    // If the request is a blob URI, then remember that URI so that we
+    // can later just use that blob instance instead of cloning it.
+    nsCString blobURISpec;
+    GetBlobURISpecFromChannel(aRequest, blobURISpec);
+    if (!blobURISpec.IsVoid()) {
+      response->SetBodyBlobURISpec(blobURISpec);
+    }
+  }
+
+  response->InitChannelInfo(channel);
+
+  nsCOMPtr<nsIURI> channelURI;
+  rv = channel->GetURI(getter_AddRefs(channelURI));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    FailWithNetworkError(rv);
+    // Cancel request.
+    return rv;
+  }
+
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+  // Propagate any tainting from the channel back to our response here.  This
+  // step is not reflected in the spec because the spec is written such that
+  // FetchEvent.respondWith() just passes the already-tainted Response back to
+  // the outer fetch().  In gecko, however, we serialize the Response through
+  // the channel and must regenerate the tainting from the channel in the
+  // interception case.
+  mRequest->MaybeIncreaseResponseTainting(loadInfo->GetTainting());
+
+  // Resolves fetch() promise which may trigger code running in a worker.  Make
+  // sure the Response is fully initialized before calling this.
+  mResponse = BeginAndGetFilteredResponse(response, foundOpaqueRedirect);
+  if (NS_WARN_IF(!mResponse)) {
+    // Fail to generate a paddingInfo for opaque response.
+    MOZ_DIAGNOSTIC_ASSERT(mRequest->GetResponseTainting() ==
+                              LoadTainting::Opaque &&
+                          !foundOpaqueRedirect);
+    FailWithNetworkError(NS_ERROR_UNEXPECTED);
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // From "Main Fetch" step 19: SRI-part1.
+  if (ShouldCheckSRI(*mRequest, *mResponse) && mSRIMetadata.IsEmpty()) {
+    nsIConsoleReportCollector* reporter = nullptr;
+    if (mObserver) {
+      reporter = mObserver->GetReporter();
+    }
+
+    nsAutoCString sourceUri;
+    if (mDocument && mDocument->GetDocumentURI()) {
+      mDocument->GetDocumentURI()->GetAsciiSpec(sourceUri);
+    } else if (!mWorkerScript.IsEmpty()) {
+      sourceUri.Assign(mWorkerScript);
+    }
+    SRICheck::IntegrityMetadata(mRequest->GetIntegrity(), sourceUri, reporter,
+                                &mSRIMetadata);
+    mSRIDataVerifier =
+        MakeUnique<SRICheckDataVerifier>(mSRIMetadata, sourceUri, reporter);
+
+    // Do not retarget off main thread when using SRI API.
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIEventTarget> sts =
+      do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    FailWithNetworkError(rv);
+    // Cancel request.
+    return rv;
+  }
+
+  // Try to retarget off main thread.
+  if (nsCOMPtr<nsIThreadRetargetableRequest> rr = do_QueryInterface(aRequest)) {
+    Unused << NS_WARN_IF(NS_FAILED(rr->RetargetDeliveryTo(sts)));
+  }
+  return NS_OK;
+}
+
+namespace {
+
+// Runnable to call the observer OnDataAvailable on the main-thread.
+class DataAvailableRunnable final : public Runnable {
+  RefPtr<FetchDriverObserver> mObserver;
+
+ public:
+  explicit DataAvailableRunnable(FetchDriverObserver* aObserver)
+      : Runnable("dom::DataAvailableRunnable"), mObserver(aObserver) {
+    MOZ_ASSERT(aObserver);
+  }
+
+  NS_IMETHOD
+  Run() override {
+    mObserver->OnDataAvailable();
+    mObserver = nullptr;
+    return NS_OK;
+  }
+};
+
+struct SRIVerifierAndOutputHolder {
+  SRIVerifierAndOutputHolder(SRICheckDataVerifier* aVerifier,
+                             nsIOutputStream* aOutputStream)
+      : mVerifier(aVerifier), mOutputStream(aOutputStream) {}
+
+  SRICheckDataVerifier* mVerifier;
+  nsIOutputStream* mOutputStream;
+
+ private:
+  SRIVerifierAndOutputHolder() = delete;
+};
+
+// Just like NS_CopySegmentToStream, but also sends the data into an
+// SRICheckDataVerifier.
+nsresult CopySegmentToStreamAndSRI(nsIInputStream* aInStr, void* aClosure,
+                                   const char* aBuffer, uint32_t aOffset,
+                                   uint32_t aCount, uint32_t* aCountWritten) {
+  auto holder = static_cast<SRIVerifierAndOutputHolder*>(aClosure);
+  MOZ_DIAGNOSTIC_ASSERT(holder && holder->mVerifier && holder->mOutputStream,
+                        "Bogus holder");
+  nsresult rv = holder->mVerifier->Update(
+      aCount, reinterpret_cast<const uint8_t*>(aBuffer));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // The rest is just like NS_CopySegmentToStream.
+  *aCountWritten = 0;
+  while (aCount) {
+    uint32_t n = 0;
+    rv = holder->mOutputStream->Write(aBuffer, aCount, &n);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    aBuffer += n;
+    aCount -= n;
+    *aCountWritten += n;
+  }
+  return NS_OK;
+}
+
+}  // anonymous namespace
+
+NS_IMETHODIMP
+FetchDriver::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aInputStream,
+                             uint64_t aOffset, uint32_t aCount) {
+  // NB: This can be called on any thread!  But we're guaranteed that it is
+  // called between OnStartRequest and OnStopRequest, so we don't need to worry
+  // about races.
+
+  if (mNeedToObserveOnDataAvailable) {
+    mNeedToObserveOnDataAvailable = false;
+    if (mObserver) {
+      // Need to keep mObserver alive.
+      RefPtr<FetchDriverObserver> observer = mObserver;
+      if (NS_IsMainThread()) {
+        observer->OnDataAvailable();
+      } else {
+        RefPtr<Runnable> runnable = new DataAvailableRunnable(observer);
+        nsresult rv = mMainThreadEventTarget->Dispatch(runnable.forget(),
+                                                       NS_DISPATCH_NORMAL);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+      }
+    }
+  }
+
+  // Needs to be initialized to 0 because in some cases nsStringInputStream may
+  // not write to aRead.
+  uint32_t aRead = 0;
+  MOZ_ASSERT(mResponse);
+  MOZ_ASSERT(mPipeOutputStream);
+
+  // From "Main Fetch" step 19: SRI-part2.
+  // Note: Avoid checking the hidden opaque body.
+  nsresult rv;
+  if (mResponse->Type() != ResponseType::Opaque &&
+      ShouldCheckSRI(*mRequest, *mResponse)) {
+    MOZ_ASSERT(mSRIDataVerifier);
+
+    SRIVerifierAndOutputHolder holder(mSRIDataVerifier.get(),
+                                      mPipeOutputStream);
+    rv = aInputStream->ReadSegments(CopySegmentToStreamAndSRI, &holder, aCount,
+                                    &aRead);
+  } else {
+    rv = aInputStream->ReadSegments(NS_CopySegmentToStream, mPipeOutputStream,
+                                    aCount, &aRead);
+  }
+
+  // If no data was read, it's possible the output stream is closed but the
+  // ReadSegments call followed its contract of returning NS_OK despite write
+  // errors.  Unfortunately, nsIOutputStream has an ill-conceived contract when
+  // taken together with ReadSegments' contract, because the pipe will just
+  // NS_OK if we try and invoke its Write* functions ourselves with a 0 count.
+  // So we must just assume the pipe is broken.
+  if (aRead == 0 && aCount != 0) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+FetchDriver::OnStopRequest(nsIRequest* aRequest, nsresult aStatusCode) {
+  AssertIsOnMainThread();
+
+  MOZ_DIAGNOSTIC_ASSERT(!mOnStopRequestCalled);
+  mOnStopRequestCalled = true;
+
+  // main data loading is going to finish, breaking the reference cycle.
+  RefPtr<AlternativeDataStreamListener> altDataListener =
+      std::move(mAltDataListener);
+
+  // We need to check mObserver, which is nulled by FailWithNetworkError(),
+  // because in the case of "error" redirect mode, aStatusCode may be NS_OK but
+  // mResponse will definitely be null so we must not take the else branch.
+  if (NS_FAILED(aStatusCode) || !mObserver) {
+    nsCOMPtr<nsIAsyncOutputStream> outputStream =
+        do_QueryInterface(mPipeOutputStream);
+    if (outputStream) {
+      outputStream->CloseWithStatus(NS_FAILED(aStatusCode) ? aStatusCode
+                                                           : NS_BINDING_FAILED);
+    }
+    if (altDataListener) {
+      altDataListener->Cancel();
+    }
+
+    // We proceed as usual here, since we've already created a successful
+    // response from OnStartRequest.
+  } else {
+    MOZ_ASSERT(mResponse);
+    MOZ_ASSERT(!mResponse->IsError());
+
+    // From "Main Fetch" step 19: SRI-part3.
+    if (ShouldCheckSRI(*mRequest, *mResponse)) {
+      MOZ_ASSERT(mSRIDataVerifier);
+
+      nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
+
+      nsIConsoleReportCollector* reporter = nullptr;
+      if (mObserver) {
+        reporter = mObserver->GetReporter();
+      }
+
+      nsAutoCString sourceUri;
+      if (mDocument && mDocument->GetDocumentURI()) {
+        mDocument->GetDocumentURI()->GetAsciiSpec(sourceUri);
+      } else if (!mWorkerScript.IsEmpty()) {
+        sourceUri.Assign(mWorkerScript);
+      }
+      nsresult rv =
+          mSRIDataVerifier->Verify(mSRIMetadata, channel, sourceUri, reporter);
+      if (NS_FAILED(rv)) {
+        if (altDataListener) {
+          altDataListener->Cancel();
+        }
+        FailWithNetworkError(rv);
+        // Cancel request.
+        return rv;
+      }
+    }
+
+    if (mPipeOutputStream) {
+      mPipeOutputStream->Close();
+    }
+  }
+
+  FinishOnStopRequest(altDataListener);
+  return NS_OK;
+}
+
+void FetchDriver::FinishOnStopRequest(
+    AlternativeDataStreamListener* aAltDataListener) {
+  AssertIsOnMainThread();
+  // OnStopRequest is not called from channel, that means the main data loading
+  // does not finish yet. Reaching here since alternative data loading finishes.
+  if (!mOnStopRequestCalled) {
+    return;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(!mAltDataListener);
+  // Wait for alternative data loading finish if we needed it.
+  if (aAltDataListener &&
+      aAltDataListener->Status() == AlternativeDataStreamListener::LOADING) {
+    // For LOADING case, channel holds the reference of altDataListener, no need
+    // to restore it to mAltDataListener.
+    return;
+  }
+
+  if (mObserver) {
+    // From "Main Fetch" step 19.1, 19.2: Process response.
+    if (ShouldCheckSRI(*mRequest, *mResponse)) {
+      MOZ_ASSERT(mResponse);
+      // Need to keep mObserver alive.
+      RefPtr<FetchDriverObserver> observer = mObserver;
+      observer->OnResponseAvailable(mResponse);
+#ifdef DEBUG
+      mResponseAvailableCalled = true;
+#endif
+    }
+  }
+
+  if (mObserver) {
+    mObserver->OnResponseEnd(FetchDriverObserver::eByNetworking);
+    mObserver = nullptr;
+  }
+
+  mChannel = nullptr;
+}
+
+NS_IMETHODIMP
+FetchDriver::AsyncOnChannelRedirect(nsIChannel* aOldChannel,
+                                    nsIChannel* aNewChannel, uint32_t aFlags,
+                                    nsIAsyncVerifyRedirectCallback* aCallback) {
+  nsCOMPtr<nsIHttpChannel> oldHttpChannel = do_QueryInterface(aOldChannel);
+  nsCOMPtr<nsIHttpChannel> newHttpChannel = do_QueryInterface(aNewChannel);
+  if (oldHttpChannel && newHttpChannel) {
+    nsAutoCString method;
+    mRequest->GetMethod(method);
+
+    // Fetch 4.4.11
+    bool rewriteToGET = false;
+    Unused << oldHttpChannel->ShouldStripRequestBodyHeader(method,
+                                                           &rewriteToGET);
+
+    SetRequestHeaders(newHttpChannel, rewriteToGET);
+  }
+
+  // "HTTP-redirect fetch": step 14 "Append locationURL to request's URL list."
+  // However, ignore internal redirects here.  We don't want to flip
+  // Response.redirected to true if an internal redirect occurs.  These
+  // should be transparent to script.
+  nsCOMPtr<nsIURI> uri;
+  MOZ_ALWAYS_SUCCEEDS(aNewChannel->GetURI(getter_AddRefs(uri)));
+
+  nsCOMPtr<nsIURI> uriClone;
+  nsresult rv = NS_GetURIWithoutRef(uri, getter_AddRefs(uriClone));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  nsCString spec;
+  rv = uriClone->GetSpec(spec);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  nsCString fragment;
+  rv = uri->GetRef(fragment);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!(aFlags & nsIChannelEventSink::REDIRECT_INTERNAL)) {
+    mRequest->AddURL(spec, fragment);
+  } else {
+    // Overwrite the URL only when the request is redirected by a service
+    // worker.
+    mRequest->SetURLForInternalRedirect(aFlags, spec, fragment);
+  }
+
+  // In redirect, httpChannel already took referrer-policy into account, so
+  // updates request’s associated referrer policy from channel.
+  UpdateReferrerInfoFromNewChannel(aNewChannel);
+
+  aCallback->OnRedirectVerifyCallback(NS_OK);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FetchDriver::CheckListenerChain() { return NS_OK; }
+
+NS_IMETHODIMP
+FetchDriver::GetInterface(const nsIID& aIID, void** aResult) {
+  if (aIID.Equals(NS_GET_IID(nsIChannelEventSink))) {
+    *aResult = static_cast<nsIChannelEventSink*>(this);
+    NS_ADDREF_THIS();
+    return NS_OK;
+  }
+  if (aIID.Equals(NS_GET_IID(nsIStreamListener))) {
+    *aResult = static_cast<nsIStreamListener*>(this);
+    NS_ADDREF_THIS();
+    return NS_OK;
+  }
+  if (aIID.Equals(NS_GET_IID(nsIRequestObserver))) {
+    *aResult = static_cast<nsIRequestObserver*>(this);
+    NS_ADDREF_THIS();
+    return NS_OK;
+  }
+
+  return QueryInterface(aIID, aResult);
+}
+
+void FetchDriver::SetDocument(Document* aDocument) {
+  // Cannot set document after Fetch() has been called.
+  MOZ_ASSERT(!mFetchCalled);
+  mDocument = aDocument;
+}
+
+void FetchDriver::SetCSPEventListener(nsICSPEventListener* aCSPEventListener) {
+  MOZ_ASSERT(!mFetchCalled);
+  mCSPEventListener = aCSPEventListener;
+}
+
+void FetchDriver::SetClientInfo(const ClientInfo& aClientInfo) {
+  MOZ_ASSERT(!mFetchCalled);
+  mClientInfo.emplace(aClientInfo);
+}
+
+void FetchDriver::SetController(
+    const Maybe<ServiceWorkerDescriptor>& aController) {
+  MOZ_ASSERT(!mFetchCalled);
+  mController = aController;
+}
+
+void FetchDriver::SetRequestHeaders(nsIHttpChannel* aChannel,
+                                    bool aStripRequestBodyHeader) const {
+  MOZ_ASSERT(aChannel);
+
+  // nsIHttpChannel has a set of pre-configured headers (Accept,
+  // Accept-Languages, ...) and we don't want to merge the Request's headers
+  // with them. This array is used to know if the current header has been aleady
+  // set, if yes, we ask necko to merge it with the previous one, otherwise, we
+  // don't want the merge.
+  nsTArray<nsCString> headersSet;
+
+  AutoTArray<InternalHeaders::Entry, 5> headers;
+  mRequest->Headers()->GetEntries(headers);
+  for (uint32_t i = 0; i < headers.Length(); ++i) {
+    if (aStripRequestBodyHeader &&
+        (headers[i].mName.LowerCaseEqualsASCII("content-type") ||
+         headers[i].mName.LowerCaseEqualsASCII("content-encoding") ||
+         headers[i].mName.LowerCaseEqualsASCII("content-language") ||
+         headers[i].mName.LowerCaseEqualsASCII("content-location"))) {
+      continue;
+    }
+
+    bool alreadySet = headersSet.Contains(headers[i].mName);
+    if (!alreadySet) {
+      headersSet.AppendElement(headers[i].mName);
+    }
+
+    if (headers[i].mValue.IsEmpty()) {
+      DebugOnly<nsresult> rv =
+          aChannel->SetEmptyRequestHeader(headers[i].mName);
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
+    } else {
+      DebugOnly<nsresult> rv = aChannel->SetRequestHeader(
+          headers[i].mName, headers[i].mValue, alreadySet /* merge */);
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
+    }
+  }
+  nsAutoCString method;
+  mRequest->GetMethod(method);
+  if (!method.EqualsLiteral("GET") && !method.EqualsLiteral("HEAD")) {
+    nsAutoString origin;
+    if (NS_SUCCEEDED(nsContentUtils::GetUTFOrigin(mPrincipal, origin))) {
+      DebugOnly<nsresult> rv = aChannel->SetRequestHeader(
+          nsDependentCString(net::nsHttp::Origin),
+          NS_ConvertUTF16toUTF8(origin), false /* merge */);
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
+    }
+  }
+}
+
+void FetchDriver::RunAbortAlgorithm() {
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+
+  if (mObserver) {
+#ifdef DEBUG
+    mResponseAvailableCalled = true;
+#endif
+    mObserver->OnResponseEnd(FetchDriverObserver::eAborted);
+    mObserver = nullptr;
+  }
+
+  if (mChannel) {
+    mChannel->Cancel(NS_BINDING_ABORTED);
+    mChannel = nullptr;
+  }
+
+  mAborted = true;
+}
+
+}  // namespace mozilla::dom