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-rw-r--r--uriloader/preload/FetchPreloader.cpp365
1 files changed, 365 insertions, 0 deletions
diff --git a/uriloader/preload/FetchPreloader.cpp b/uriloader/preload/FetchPreloader.cpp
new file mode 100644
index 0000000000..ac580aeabc
--- /dev/null
+++ b/uriloader/preload/FetchPreloader.cpp
@@ -0,0 +1,365 @@
+/* -*- 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 "FetchPreloader.h"
+
+#include "mozilla/Assertions.h"
+#include "mozilla/CORSMode.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/LoadInfo.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/Unused.h"
+#include "mozilla/dom/ReferrerInfo.h"
+#include "nsContentPolicyUtils.h"
+#include "nsContentSecurityManager.h"
+#include "nsContentUtils.h"
+#include "nsIChannel.h"
+#include "nsIChildChannel.h"
+#include "nsIClassOfService.h"
+#include "nsIHttpChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsISupportsPriority.h"
+#include "nsITimedChannel.h"
+#include "nsNetUtil.h"
+#include "nsStringStream.h"
+#include "nsIDocShell.h"
+
+namespace mozilla {
+
+NS_IMPL_ISUPPORTS(FetchPreloader, nsIStreamListener, nsIRequestObserver)
+
+FetchPreloader::FetchPreloader()
+ : FetchPreloader(nsIContentPolicy::TYPE_INTERNAL_FETCH_PRELOAD) {}
+
+FetchPreloader::FetchPreloader(nsContentPolicyType aContentPolicyType)
+ : mContentPolicyType(aContentPolicyType) {}
+
+nsresult FetchPreloader::OpenChannel(const PreloadHashKey& aKey, nsIURI* aURI,
+ const CORSMode aCORSMode,
+ const dom::ReferrerPolicy& aReferrerPolicy,
+ dom::Document* aDocument,
+ uint64_t aEarlyHintPreloaderId,
+ int32_t aSupportsPriorityValue) {
+ nsresult rv;
+ nsCOMPtr<nsIChannel> channel;
+
+ auto notify = MakeScopeExit([&]() {
+ if (NS_FAILED(rv)) {
+ // Make sure we notify any <link preload> elements when opening fails
+ // because of various technical or security reasons.
+ NotifyStart(channel);
+ // Using the non-channel overload of this method to make it work even
+ // before NotifyOpen has been called on this preload. We are not
+ // switching between channels, so it's safe to do so.
+ NotifyStop(rv);
+ }
+ });
+
+ nsCOMPtr<nsILoadGroup> loadGroup = aDocument->GetDocumentLoadGroup();
+ nsCOMPtr<nsPIDOMWindowOuter> window = aDocument->GetWindow();
+ nsCOMPtr<nsIInterfaceRequestor> prompter;
+ if (window) {
+ nsIDocShell* docshell = window->GetDocShell();
+ prompter = do_QueryInterface(docshell);
+ }
+
+ rv = CreateChannel(getter_AddRefs(channel), aURI, aCORSMode, aReferrerPolicy,
+ aDocument, loadGroup, prompter, aEarlyHintPreloaderId,
+ aSupportsPriorityValue);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ // Doing this now so that we have the channel and tainting set on it properly
+ // to notify the proper event (load or error) on the associated preload tags
+ // when the CSP check fails.
+ rv = CheckContentPolicy(aURI, aDocument);
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ FetchPreloader::PrioritizeAsPreload(channel);
+ AddLoadBackgroundFlag(channel);
+
+ NotifyOpen(aKey, channel, aDocument, true);
+
+ if (aEarlyHintPreloaderId) {
+ nsCOMPtr<nsIHttpChannelInternal> channelInternal =
+ do_QueryInterface(channel);
+ NS_ENSURE_TRUE(channelInternal != nullptr, NS_ERROR_FAILURE);
+
+ rv = channelInternal->SetEarlyHintPreloaderId(aEarlyHintPreloaderId);
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+ return mAsyncConsumeResult = rv = channel->AsyncOpen(this);
+}
+
+nsresult FetchPreloader::CreateChannel(
+ nsIChannel** aChannel, nsIURI* aURI, const CORSMode aCORSMode,
+ const dom::ReferrerPolicy& aReferrerPolicy, dom::Document* aDocument,
+ nsILoadGroup* aLoadGroup, nsIInterfaceRequestor* aCallbacks,
+ uint64_t aEarlyHintPreloaderId, int32_t aSupportsPriorityValue) {
+ nsresult rv;
+
+ nsSecurityFlags securityFlags =
+ nsContentSecurityManager::ComputeSecurityFlags(
+ aCORSMode, nsContentSecurityManager::CORSSecurityMapping::
+ CORS_NONE_MAPS_TO_DISABLED_CORS_CHECKS);
+
+ nsCOMPtr<nsIChannel> channel;
+ rv = NS_NewChannelWithTriggeringPrincipal(
+ getter_AddRefs(channel), aURI, aDocument, aDocument->NodePrincipal(),
+ securityFlags, nsIContentPolicy::TYPE_FETCH, nullptr, aLoadGroup,
+ aCallbacks);
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ AdjustPriority(channel, aSupportsPriorityValue);
+
+ if (nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(channel)) {
+ nsCOMPtr<nsIReferrerInfo> referrerInfo = new dom::ReferrerInfo(
+ aDocument->GetDocumentURIAsReferrer(), aReferrerPolicy);
+ rv = httpChannel->SetReferrerInfoWithoutClone(referrerInfo);
+ MOZ_ASSERT(NS_SUCCEEDED(rv));
+ }
+
+ if (nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(channel)) {
+ if (aEarlyHintPreloaderId) {
+ timedChannel->SetInitiatorType(u"early-hints"_ns);
+ } else {
+ timedChannel->SetInitiatorType(u"link"_ns);
+ }
+ }
+
+ channel.forget(aChannel);
+ return NS_OK;
+}
+
+// static
+void FetchPreloader::AdjustPriority(nsIChannel* aChannel,
+ int32_t aSupportsPriorityValue) {
+ if (nsCOMPtr<nsISupportsPriority> supportsPriority{
+ do_QueryInterface(aChannel)}) {
+ supportsPriority->SetPriority(aSupportsPriorityValue);
+ }
+}
+
+nsresult FetchPreloader::CheckContentPolicy(nsIURI* aURI,
+ dom::Document* aDocument) {
+ if (!aDocument) {
+ return NS_OK;
+ }
+
+ nsCOMPtr<nsILoadInfo> secCheckLoadInfo = new net::LoadInfo(
+ aDocument->NodePrincipal(), aDocument->NodePrincipal(), aDocument,
+ nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK, mContentPolicyType);
+
+ int16_t shouldLoad = nsIContentPolicy::ACCEPT;
+ nsresult rv = NS_CheckContentLoadPolicy(aURI, secCheckLoadInfo, &shouldLoad,
+ nsContentUtils::GetContentPolicy());
+ if (NS_SUCCEEDED(rv) && NS_CP_ACCEPTED(shouldLoad)) {
+ return NS_OK;
+ }
+
+ return NS_ERROR_CONTENT_BLOCKED;
+}
+
+// PreloaderBase
+
+nsresult FetchPreloader::AsyncConsume(nsIStreamListener* aListener) {
+ if (NS_FAILED(mAsyncConsumeResult)) {
+ // Already being consumed or failed to open.
+ return mAsyncConsumeResult;
+ }
+
+ // Prevent duplicate calls.
+ mAsyncConsumeResult = NS_ERROR_NOT_AVAILABLE;
+
+ if (!mConsumeListener) {
+ // Called before we are getting response from the channel.
+ mConsumeListener = aListener;
+ } else {
+ // Channel already started, push cached calls to this listener.
+ // Can't be anything else than the `Cache`, hence a safe static_cast.
+ Cache* cache = static_cast<Cache*>(mConsumeListener.get());
+ cache->AsyncConsume(aListener);
+ }
+
+ return NS_OK;
+}
+
+// static
+void FetchPreloader::PrioritizeAsPreload(nsIChannel* aChannel) {
+ if (nsCOMPtr<nsIClassOfService> cos = do_QueryInterface(aChannel)) {
+ cos->AddClassFlags(nsIClassOfService::Unblocked);
+ }
+}
+
+// nsIRequestObserver + nsIStreamListener
+
+NS_IMETHODIMP FetchPreloader::OnStartRequest(nsIRequest* request) {
+ NotifyStart(request);
+
+ if (!mConsumeListener) {
+ // AsyncConsume not called yet.
+ mConsumeListener = new Cache();
+ }
+
+ return mConsumeListener->OnStartRequest(request);
+}
+
+NS_IMETHODIMP FetchPreloader::OnDataAvailable(nsIRequest* request,
+ nsIInputStream* input,
+ uint64_t offset, uint32_t count) {
+ return mConsumeListener->OnDataAvailable(request, input, offset, count);
+}
+
+NS_IMETHODIMP FetchPreloader::OnStopRequest(nsIRequest* request,
+ nsresult status) {
+ mConsumeListener->OnStopRequest(request, status);
+
+ // We want 404 or other types of server responses to be treated as 'error'.
+ if (nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(request)) {
+ uint32_t responseStatus = 0;
+ Unused << httpChannel->GetResponseStatus(&responseStatus);
+ if (responseStatus / 100 != 2) {
+ status = NS_ERROR_FAILURE;
+ }
+ }
+
+ // Fetch preloader wants to keep the channel around so that consumers like XHR
+ // can access it even after the preload is done.
+ nsCOMPtr<nsIChannel> channel = mChannel;
+ NotifyStop(request, status);
+ mChannel.swap(channel);
+ return NS_OK;
+}
+
+// FetchPreloader::Cache
+
+NS_IMPL_ISUPPORTS(FetchPreloader::Cache, nsIStreamListener, nsIRequestObserver)
+
+NS_IMETHODIMP FetchPreloader::Cache::OnStartRequest(nsIRequest* request) {
+ mRequest = request;
+
+ if (mFinalListener) {
+ return mFinalListener->OnStartRequest(mRequest);
+ }
+
+ mCalls.AppendElement(Call{VariantIndex<0>{}, StartRequest{}});
+ return NS_OK;
+}
+
+NS_IMETHODIMP FetchPreloader::Cache::OnDataAvailable(nsIRequest* request,
+ nsIInputStream* input,
+ uint64_t offset,
+ uint32_t count) {
+ if (mFinalListener) {
+ return mFinalListener->OnDataAvailable(mRequest, input, offset, count);
+ }
+
+ DataAvailable data;
+ if (!data.mData.SetLength(count, fallible)) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ uint32_t read;
+ nsresult rv = input->Read(data.mData.BeginWriting(), count, &read);
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ mCalls.AppendElement(Call{VariantIndex<1>{}, std::move(data)});
+ return NS_OK;
+}
+
+NS_IMETHODIMP FetchPreloader::Cache::OnStopRequest(nsIRequest* request,
+ nsresult status) {
+ if (mFinalListener) {
+ return mFinalListener->OnStopRequest(mRequest, status);
+ }
+
+ mCalls.AppendElement(Call{VariantIndex<2>{}, StopRequest{status}});
+ return NS_OK;
+}
+
+void FetchPreloader::Cache::AsyncConsume(nsIStreamListener* aListener) {
+ // Must dispatch for two reasons:
+ // 1. This is called directly from FetchLoader::AsyncConsume, which must
+ // behave the same way as nsIChannel::AsyncOpen.
+ // 2. In case there are already stream listener events scheduled on the main
+ // thread we preserve the order - those will still end up in Cache.
+
+ // * The `Cache` object is fully main thread only for now, doesn't support
+ // retargeting, but it can be improved to allow it.
+
+ nsCOMPtr<nsIStreamListener> listener(aListener);
+ NS_DispatchToMainThread(NewRunnableMethod<nsCOMPtr<nsIStreamListener>>(
+ "FetchPreloader::Cache::Consume", this, &FetchPreloader::Cache::Consume,
+ listener));
+}
+
+void FetchPreloader::Cache::Consume(nsCOMPtr<nsIStreamListener> aListener) {
+ MOZ_ASSERT(!mFinalListener, "Duplicate call");
+
+ mFinalListener = std::move(aListener);
+
+ // Status of the channel read after each call.
+ nsresult status = NS_OK;
+ nsCOMPtr<nsIChannel> channel(do_QueryInterface(mRequest));
+
+ RefPtr<Cache> self(this);
+ for (auto& call : mCalls) {
+ nsresult rv = call.match(
+ [&](const StartRequest& startRequest) mutable {
+ return self->mFinalListener->OnStartRequest(self->mRequest);
+ },
+ [&](const DataAvailable& dataAvailable) mutable {
+ if (NS_FAILED(status)) {
+ // Channel has been cancelled during this mCalls loop.
+ return NS_OK;
+ }
+
+ nsCOMPtr<nsIInputStream> input;
+ rv = NS_NewCStringInputStream(getter_AddRefs(input),
+ dataAvailable.mData);
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ return self->mFinalListener->OnDataAvailable(
+ self->mRequest, input, 0, dataAvailable.mData.Length());
+ },
+ [&](const StopRequest& stopRequest) {
+ // First cancellation overrides mStatus in nsHttpChannel.
+ nsresult stopStatus =
+ NS_FAILED(status) ? status : stopRequest.mStatus;
+ self->mFinalListener->OnStopRequest(self->mRequest, stopStatus);
+ self->mFinalListener = nullptr;
+ self->mRequest = nullptr;
+ return NS_OK;
+ });
+
+ if (!mRequest) {
+ // We are done!
+ break;
+ }
+
+ bool isCancelled = false;
+ Unused << channel->GetCanceled(&isCancelled);
+ if (isCancelled) {
+ mRequest->GetStatus(&status);
+ } else if (NS_FAILED(rv)) {
+ status = rv;
+ mRequest->Cancel(status);
+ }
+ }
+
+ mCalls.Clear();
+}
+
+} // namespace mozilla