1 files changed, 468 insertions, 0 deletions
diff --git a/netwerk/protocol/res/PageThumbProtocolHandler.cpp b/netwerk/protocol/res/PageThumbProtocolHandler.cpp
new file mode 100644
index 0000000000..02ee4e67cf
--- /dev/null
+++ b/netwerk/protocol/res/PageThumbProtocolHandler.cpp
@@ -0,0 +1,468 @@
+/* -*- 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 "PageThumbProtocolHandler.h"
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/ipc/URIParams.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/ResultExtensions.h"
+
+#include "LoadInfo.h"
+#include "nsContentUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIFile.h"
+#include "nsIFileChannel.h"
+#include "nsIFileStreams.h"
+#include "nsIMIMEService.h"
+#include "nsIURL.h"
+#include "nsIChannel.h"
+#include "nsIPageThumbsStorageService.h"
+#include "nsIInputStreamPump.h"
+#include "nsIStreamListener.h"
+#include "nsIInputStream.h"
+#include "nsNetUtil.h"
+#include "nsURLHelper.h"
+#include "prio.h"
+#include "SimpleChannel.h"
+
+#define PAGE_THUMB_HOST "thumbnails"
+#define PAGE_THUMB_SCHEME "moz-page-thumb"
+
+namespace mozilla {
+namespace net {
+
+LazyLogModule gPageThumbProtocolLog("PageThumbProtocol");
+
+#undef LOG
+#define LOG(level, ...) \
+  MOZ_LOG(gPageThumbProtocolLog, LogLevel::level, (__VA_ARGS__))
+
+StaticRefPtr<PageThumbProtocolHandler> PageThumbProtocolHandler::sSingleton;
+
+/**
+ * Helper class used with SimpleChannel to asynchronously obtain an input
+ * stream from the parent for a remote moz-page-thumb load from the child.
+ */
+class PageThumbStreamGetter : public RefCounted<PageThumbStreamGetter> {
+ public:
+  PageThumbStreamGetter(nsIURI* aURI, nsILoadInfo* aLoadInfo)
+      : mURI(aURI), mLoadInfo(aLoadInfo) {
+    MOZ_ASSERT(aURI);
+    MOZ_ASSERT(aLoadInfo);
+
+    SetupEventTarget();
+  }
+
+  ~PageThumbStreamGetter() = default;
+
+  void SetupEventTarget() {
+    mMainThreadEventTarget = nsContentUtils::GetEventTargetByLoadInfo(
+        mLoadInfo, TaskCategory::Other);
+    if (!mMainThreadEventTarget) {
+      mMainThreadEventTarget = GetMainThreadSerialEventTarget();
+    }
+  }
+
+  // Get an input stream from the parent asynchronously.
+  Result<Ok, nsresult> GetAsync(nsIStreamListener* aListener,
+                                nsIChannel* aChannel);
+
+  // Handle an input stream being returned from the parent
+  void OnStream(already_AddRefed<nsIInputStream> aStream);
+
+  static void CancelRequest(nsIStreamListener* aListener, nsIChannel* aChannel,
+                            nsresult aResult);
+
+  MOZ_DECLARE_REFCOUNTED_TYPENAME(PageThumbStreamGetter)
+
+ private:
+  nsCOMPtr<nsIURI> mURI;
+  nsCOMPtr<nsILoadInfo> mLoadInfo;
+  nsCOMPtr<nsIStreamListener> mListener;
+  nsCOMPtr<nsIChannel> mChannel;
+  nsCOMPtr<nsISerialEventTarget> mMainThreadEventTarget;
+};
+
+// Request an input stream from the parent.
+Result<Ok, nsresult> PageThumbStreamGetter::GetAsync(
+    nsIStreamListener* aListener, nsIChannel* aChannel) {
+  MOZ_ASSERT(IsNeckoChild());
+  MOZ_ASSERT(mMainThreadEventTarget);
+
+  mListener = aListener;
+  mChannel = aChannel;
+
+  RefPtr<PageThumbStreamGetter> self = this;
+
+  // Request an input stream for this moz-page-thumb URI.
+  gNeckoChild->SendGetPageThumbStream(mURI)->Then(
+      mMainThreadEventTarget, __func__,
+      [self](const RefPtr<nsIInputStream>& stream) {
+        self->OnStream(do_AddRef(stream));
+      },
+      [self](const mozilla::ipc::ResponseRejectReason) {
+        self->OnStream(nullptr);
+      });
+  return Ok();
+}
+
+// static
+void PageThumbStreamGetter::CancelRequest(nsIStreamListener* aListener,
+                                          nsIChannel* aChannel,
+                                          nsresult aResult) {
+  MOZ_ASSERT(aListener);
+  MOZ_ASSERT(aChannel);
+
+  aListener->OnStartRequest(aChannel);
+  aListener->OnStopRequest(aChannel, aResult);
+  aChannel->Cancel(NS_BINDING_ABORTED);
+}
+
+// Handle an input stream sent from the parent.
+void PageThumbStreamGetter::OnStream(already_AddRefed<nsIInputStream> aStream) {
+  MOZ_ASSERT(IsNeckoChild());
+  MOZ_ASSERT(mListener);
+  MOZ_ASSERT(mMainThreadEventTarget);
+
+  nsCOMPtr<nsIInputStream> stream = std::move(aStream);
+
+  // We must keep an owning reference to the listener until we pass it on
+  // to AsyncRead.
+  nsCOMPtr<nsIStreamListener> listener = mListener.forget();
+
+  MOZ_ASSERT(mChannel);
+
+  if (!stream) {
+    // The parent didn't send us back a stream.
+    CancelRequest(listener, mChannel, NS_ERROR_FILE_ACCESS_DENIED);
+    return;
+  }
+
+  nsCOMPtr<nsIInputStreamPump> pump;
+  nsresult rv = NS_NewInputStreamPump(getter_AddRefs(pump), stream.forget(), 0,
+                                      0, false, mMainThreadEventTarget);
+  if (NS_FAILED(rv)) {
+    CancelRequest(listener, mChannel, rv);
+    return;
+  }
+
+  rv = pump->AsyncRead(listener);
+  if (NS_FAILED(rv)) {
+    CancelRequest(listener, mChannel, rv);
+  }
+}
+
+NS_IMPL_QUERY_INTERFACE(PageThumbProtocolHandler,
+                        nsISubstitutingProtocolHandler, nsIProtocolHandler,
+                        nsIProtocolHandlerWithDynamicFlags,
+                        nsISupportsWeakReference)
+NS_IMPL_ADDREF_INHERITED(PageThumbProtocolHandler, SubstitutingProtocolHandler)
+NS_IMPL_RELEASE_INHERITED(PageThumbProtocolHandler, SubstitutingProtocolHandler)
+
+already_AddRefed<PageThumbProtocolHandler>
+PageThumbProtocolHandler::GetSingleton() {
+  if (!sSingleton) {
+    sSingleton = new PageThumbProtocolHandler();
+    ClearOnShutdown(&sSingleton);
+  }
+
+  return do_AddRef(sSingleton);
+}
+
+PageThumbProtocolHandler::PageThumbProtocolHandler()
+    : SubstitutingProtocolHandler(PAGE_THUMB_SCHEME) {}
+
+nsresult PageThumbProtocolHandler::GetFlagsForURI(nsIURI* aURI,
+                                                  uint32_t* aFlags) {
+  // A moz-page-thumb URI is only loadable by chrome pages in the parent
+  // process, or privileged content running in the privileged about content
+  // process.
+  *aFlags = URI_STD | URI_IS_UI_RESOURCE | URI_IS_LOCAL_RESOURCE |
+            URI_NORELATIVE | URI_NOAUTH;
+
+  return NS_OK;
+}
+
+RefPtr<PageThumbStreamPromise> PageThumbProtocolHandler::NewStream(
+    nsIURI* aChildURI, bool* aTerminateSender) {
+  MOZ_ASSERT(!IsNeckoChild());
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!aChildURI || !aTerminateSender) {
+    return PageThumbStreamPromise::CreateAndReject(NS_ERROR_INVALID_ARG,
+                                                   __func__);
+  }
+
+  *aTerminateSender = true;
+  nsresult rv;
+
+  // We should never receive a URI that isn't for a moz-page-thumb because
+  // these requests ordinarily come from the child's PageThumbProtocolHandler.
+  // Ensure this request is for a moz-page-thumb URI. A compromised child
+  // process could send us any URI.
+  bool isPageThumbScheme = false;
+  if (NS_FAILED(aChildURI->SchemeIs(PAGE_THUMB_SCHEME, &isPageThumbScheme)) ||
+      !isPageThumbScheme) {
+    return PageThumbStreamPromise::CreateAndReject(NS_ERROR_UNKNOWN_PROTOCOL,
+                                                   __func__);
+  }
+
+  // We should never receive a URI that does not have "thumbnails" as the host.
+  nsAutoCString host;
+  if (NS_FAILED(aChildURI->GetAsciiHost(host)) ||
+      !host.EqualsLiteral(PAGE_THUMB_HOST)) {
+    return PageThumbStreamPromise::CreateAndReject(NS_ERROR_UNEXPECTED,
+                                                   __func__);
+  }
+
+  // For errors after this point, we want to propagate the error to
+  // the child, but we don't force the child process to be terminated.
+  *aTerminateSender = false;
+
+  // Make sure the child URI resolves to a file URI. We will then get a file
+  // channel for the request. The resultant channel should be a file channel
+  // because we only request remote streams for resource loads where the URI
+  // resolves to a file.
+  nsAutoCString resolvedSpec;
+  rv = ResolveURI(aChildURI, resolvedSpec);
+  if (NS_FAILED(rv)) {
+    return PageThumbStreamPromise::CreateAndReject(rv, __func__);
+  }
+
+  nsAutoCString resolvedScheme;
+  rv = net_ExtractURLScheme(resolvedSpec, resolvedScheme);
+  if (NS_FAILED(rv) || !resolvedScheme.EqualsLiteral("file")) {
+    return PageThumbStreamPromise::CreateAndReject(NS_ERROR_UNEXPECTED,
+                                                   __func__);
+  }
+
+  nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
+  if (NS_FAILED(rv)) {
+    return PageThumbStreamPromise::CreateAndReject(rv, __func__);
+  }
+
+  nsCOMPtr<nsIURI> resolvedURI;
+  rv = ioService->NewURI(resolvedSpec, nullptr, nullptr,
+                         getter_AddRefs(resolvedURI));
+  if (NS_FAILED(rv)) {
+    return PageThumbStreamPromise::CreateAndReject(rv, __func__);
+  }
+
+  // We use the system principal to get a file channel for the request,
+  // but only after we've checked (above) that the child URI is of
+  // moz-page-thumb scheme and that the URI host matches PAGE_THUMB_HOST.
+  nsCOMPtr<nsIChannel> channel;
+  rv = NS_NewChannel(getter_AddRefs(channel), resolvedURI,
+                     nsContentUtils::GetSystemPrincipal(),
+                     nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+                     nsIContentPolicy::TYPE_OTHER);
+  if (NS_FAILED(rv)) {
+    return PageThumbStreamPromise::CreateAndReject(rv, __func__);
+  }
+
+  auto promiseHolder = MakeUnique<MozPromiseHolder<PageThumbStreamPromise>>();
+  RefPtr<PageThumbStreamPromise> promise = promiseHolder->Ensure(__func__);
+
+  rv = NS_DispatchBackgroundTask(
+      NS_NewRunnableFunction(
+          "PageThumbProtocolHandler::NewStream",
+          [channel, holder = std::move(promiseHolder)]() {
+            nsresult rv;
+
+            nsCOMPtr<nsIFileChannel> fileChannel =
+                do_QueryInterface(channel, &rv);
+            if (NS_FAILED(rv)) {
+              holder->Reject(rv, __func__);
+            }
+
+            nsCOMPtr<nsIFile> requestedFile;
+            rv = fileChannel->GetFile(getter_AddRefs(requestedFile));
+            if (NS_FAILED(rv)) {
+              holder->Reject(rv, __func__);
+              return;
+            }
+
+            nsCOMPtr<nsIInputStream> inputStream;
+            rv = NS_NewLocalFileInputStream(getter_AddRefs(inputStream),
+                                            requestedFile, PR_RDONLY, -1);
+            if (NS_FAILED(rv)) {
+              holder->Reject(rv, __func__);
+              return;
+            }
+
+            holder->Resolve(inputStream, __func__);
+          }),
+      NS_DISPATCH_EVENT_MAY_BLOCK);
+
+  if (NS_FAILED(rv)) {
+    return PageThumbStreamPromise::CreateAndReject(rv, __func__);
+  }
+
+  return promise;
+}
+
+bool PageThumbProtocolHandler::ResolveSpecialCases(const nsACString& aHost,
+                                                   const nsACString& aPath,
+                                                   const nsACString& aPathname,
+                                                   nsACString& aResult) {
+  // This should match the scheme in PageThumbs.jsm. We will only resolve
+  // URIs for thumbnails generated by PageThumbs here.
+  if (!aHost.EqualsLiteral(PAGE_THUMB_HOST)) {
+    // moz-page-thumb should always have a "thumbnails" host. We do not intend
+    // to allow substitution rules to be created for moz-page-thumb.
+    return false;
+  }
+
+  // Regardless of the outcome, the scheme will be resolved to file://.
+  aResult.Assign("file://");
+
+  if (IsNeckoChild()) {
+    // We will resolve the URI in the parent if load is performed in the child
+    // because the child does not have access to the profile directory path.
+    // Technically we could retrieve the path from dom::ContentChild, but I
+    // would prefer to obtain the path from PageThumbsStorageService (which
+    // depends on OS.Path). Here, we resolve to the same URI, with the file://
+    // scheme. This won't ever be accessed directly by the content process,
+    // and is mainly used to keep the substitution protocol handler mechanism
+    // happy.
+    aResult.Append(aHost);
+    aResult.Append(aPath);
+  } else {
+    // Resolve the URI in the parent to the thumbnail file URI since we will
+    // attempt to open the channel to load the file after this.
+    nsAutoString thumbnailUrl;
+    nsresult rv = GetThumbnailPath(aPath, thumbnailUrl);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return false;
+    }
+
+    aResult.Append(NS_ConvertUTF16toUTF8(thumbnailUrl));
+  }
+
+  return true;
+}
+
+nsresult PageThumbProtocolHandler::SubstituteChannel(nsIURI* aURI,
+                                                     nsILoadInfo* aLoadInfo,
+                                                     nsIChannel** aRetVal) {
+  // Check if URI resolves to a file URI.
+  nsAutoCString resolvedSpec;
+  MOZ_TRY(ResolveURI(aURI, resolvedSpec));
+
+  nsAutoCString scheme;
+  MOZ_TRY(net_ExtractURLScheme(resolvedSpec, scheme));
+
+  if (!scheme.EqualsLiteral("file")) {
+    NS_WARNING("moz-page-thumb URIs should only resolve to file URIs.");
+    return NS_ERROR_NO_INTERFACE;
+  }
+
+  // Load the URI remotely if accessed from a child.
+  if (IsNeckoChild()) {
+    MOZ_TRY(SubstituteRemoteChannel(aURI, aLoadInfo, aRetVal));
+  }
+
+  return NS_OK;
+}
+
+Result<Ok, nsresult> PageThumbProtocolHandler::SubstituteRemoteChannel(
+    nsIURI* aURI, nsILoadInfo* aLoadInfo, nsIChannel** aRetVal) {
+  MOZ_ASSERT(IsNeckoChild());
+  MOZ_TRY(aURI ? NS_OK : NS_ERROR_INVALID_ARG);
+  MOZ_TRY(aLoadInfo ? NS_OK : NS_ERROR_INVALID_ARG);
+
+#ifdef DEBUG
+  nsAutoCString resolvedSpec;
+  MOZ_TRY(ResolveURI(aURI, resolvedSpec));
+
+  nsAutoCString scheme;
+  MOZ_TRY(net_ExtractURLScheme(resolvedSpec, scheme));
+
+  MOZ_ASSERT(scheme.EqualsLiteral("file"));
+#endif /* DEBUG */
+
+  RefPtr<PageThumbStreamGetter> streamGetter =
+      new PageThumbStreamGetter(aURI, aLoadInfo);
+
+  NewSimpleChannel(aURI, aLoadInfo, streamGetter, aRetVal);
+  return Ok();
+}
+
+nsresult PageThumbProtocolHandler::GetThumbnailPath(const nsACString& aPath,
+                                                    nsString& aThumbnailPath) {
+  MOZ_ASSERT(!IsNeckoChild());
+
+  // Ensures that the provided path has a query string. We will start parsing
+  // from there.
+  int32_t queryIndex = aPath.FindChar('?');
+  if (queryIndex <= 0) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsresult rv;
+
+  nsCOMPtr<nsIPageThumbsStorageService> pageThumbsStorage =
+      do_GetService("@mozilla.org/thumbnails/pagethumbs-service;1", &rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // Extract URL from query string.
+  nsAutoString url;
+  bool found =
+      URLParams::Extract(Substring(aPath, queryIndex + 1), u"url"_ns, url);
+  if (!found || url.IsVoid()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Use PageThumbsStorageService to get the local file path of the screenshot
+  // for the given URL.
+  rv = pageThumbsStorage->GetFilePathForURL(url, aThumbnailPath);
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+// static
+void PageThumbProtocolHandler::SetContentType(nsIURI* aURI,
+                                              nsIChannel* aChannel) {
+  nsresult rv;
+  nsCOMPtr<nsIMIMEService> mime = do_GetService("@mozilla.org/mime;1", &rv);
+  if (NS_SUCCEEDED(rv)) {
+    nsAutoCString contentType;
+    rv = mime->GetTypeFromURI(aURI, contentType);
+    if (NS_SUCCEEDED(rv)) {
+      Unused << aChannel->SetContentType(contentType);
+    }
+  }
+}
+
+// static
+void PageThumbProtocolHandler::NewSimpleChannel(
+    nsIURI* aURI, nsILoadInfo* aLoadinfo, PageThumbStreamGetter* aStreamGetter,
+    nsIChannel** aRetVal) {
+  nsCOMPtr<nsIChannel> channel = NS_NewSimpleChannel(
+      aURI, aLoadinfo, aStreamGetter,
+      [](nsIStreamListener* listener, nsIChannel* simpleChannel,
+         PageThumbStreamGetter* getter) -> RequestOrReason {
+        MOZ_TRY(getter->GetAsync(listener, simpleChannel));
+        return RequestOrReason(nullptr);
+      });
+
+  SetContentType(aURI, channel);
+  channel.swap(*aRetVal);
+}
+
+#undef LOG
+
+}  // namespace net
+}  // namespace mozilla