1 files changed, 472 insertions, 0 deletions
diff --git a/dom/script/ScriptLoadHandler.cpp b/dom/script/ScriptLoadHandler.cpp
new file mode 100644
index 0000000000..2d5f2bfbf6
--- /dev/null
+++ b/dom/script/ScriptLoadHandler.cpp
@@ -0,0 +1,472 @@
+/* -*- 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 "ScriptLoadHandler.h"
+
+#include <stdlib.h>
+#include <utility>
+#include "ScriptLoader.h"
+#include "ScriptTrace.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Encoding.h"
+#include "mozilla/Logging.h"
+#include "mozilla/NotNull.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "mozilla/Tuple.h"
+#include "mozilla/Utf8.h"
+#include "mozilla/Vector.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/SRICheck.h"
+#include "mozilla/dom/ScriptDecoding.h"
+#include "mozilla/dom/ScriptLoadRequest.h"
+#include "nsCOMPtr.h"
+#include "nsContentUtils.h"
+#include "nsDebug.h"
+#include "nsICacheInfoChannel.h"
+#include "nsIChannel.h"
+#include "nsIHttpChannel.h"
+#include "nsIRequest.h"
+#include "nsIScriptElement.h"
+#include "nsIURI.h"
+#include "nsJSUtils.h"
+#include "nsMimeTypes.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace dom {
+
+#undef LOG
+#define LOG(args) \
+  MOZ_LOG(ScriptLoader::gScriptLoaderLog, mozilla::LogLevel::Debug, args)
+
+#define LOG_ENABLED() \
+  MOZ_LOG_TEST(ScriptLoader::gScriptLoaderLog, mozilla::LogLevel::Debug)
+
+ScriptLoadHandler::ScriptLoadHandler(
+    ScriptLoader* aScriptLoader, ScriptLoadRequest* aRequest,
+    UniquePtr<SRICheckDataVerifier>&& aSRIDataVerifier)
+    : mScriptLoader(aScriptLoader),
+      mRequest(aRequest),
+      mSRIDataVerifier(std::move(aSRIDataVerifier)),
+      mSRIStatus(NS_OK),
+      mDecoder() {
+  MOZ_ASSERT(mRequest->IsUnknownDataType());
+  MOZ_ASSERT(mRequest->IsLoading());
+}
+
+ScriptLoadHandler::~ScriptLoadHandler() = default;
+
+NS_IMPL_ISUPPORTS(ScriptLoadHandler, nsIIncrementalStreamLoaderObserver)
+
+template <typename Unit>
+nsresult ScriptLoadHandler::DecodeRawDataHelper(const uint8_t* aData,
+                                                uint32_t aDataLength,
+                                                bool aEndOfStream) {
+  CheckedInt<size_t> needed =
+      ScriptDecoding<Unit>::MaxBufferLength(mDecoder, aDataLength);
+  if (!needed.isValid()) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // Reference to the script source buffer which we will update.
+  ScriptLoadRequest::ScriptTextBuffer<Unit>& scriptText =
+      mRequest->ScriptText<Unit>();
+
+  uint32_t haveRead = scriptText.length();
+
+  CheckedInt<uint32_t> capacity = haveRead;
+  capacity += needed.value();
+
+  if (!capacity.isValid() || !scriptText.resize(capacity.value())) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  size_t written = ScriptDecoding<Unit>::DecodeInto(
+      mDecoder, Span(aData, aDataLength),
+      Span(scriptText.begin() + haveRead, needed.value()), aEndOfStream);
+  MOZ_ASSERT(written <= needed.value());
+
+  haveRead += written;
+  MOZ_ASSERT(haveRead <= capacity.value(),
+             "mDecoder produced more data than expected");
+  MOZ_ALWAYS_TRUE(scriptText.resize(haveRead));
+  mRequest->mScriptTextLength = scriptText.length();
+
+  return NS_OK;
+}
+
+nsresult ScriptLoadHandler::DecodeRawData(const uint8_t* aData,
+                                          uint32_t aDataLength,
+                                          bool aEndOfStream) {
+  if (mRequest->IsUTF16Text()) {
+    return DecodeRawDataHelper<char16_t>(aData, aDataLength, aEndOfStream);
+  }
+
+  return DecodeRawDataHelper<Utf8Unit>(aData, aDataLength, aEndOfStream);
+}
+
+NS_IMETHODIMP
+ScriptLoadHandler::OnIncrementalData(nsIIncrementalStreamLoader* aLoader,
+                                     nsISupports* aContext,
+                                     uint32_t aDataLength, const uint8_t* aData,
+                                     uint32_t* aConsumedLength) {
+  nsCOMPtr<nsIRequest> channelRequest;
+  aLoader->GetRequest(getter_AddRefs(channelRequest));
+
+  if (!mPreloadStartNotified) {
+    mPreloadStartNotified = true;
+    mRequest->NotifyStart(channelRequest);
+  }
+
+  if (mRequest->IsCanceled()) {
+    // If request cancelled, ignore any incoming data.
+    *aConsumedLength = aDataLength;
+    return NS_OK;
+  }
+
+  nsresult rv = NS_OK;
+  if (mRequest->IsUnknownDataType()) {
+    rv = EnsureKnownDataType(aLoader);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (mRequest->IsTextSource()) {
+    if (!EnsureDecoder(aLoader, aData, aDataLength,
+                       /* aEndOfStream = */ false)) {
+      return NS_OK;
+    }
+
+    // Below we will/shall consume entire data chunk.
+    *aConsumedLength = aDataLength;
+
+    // Decoder has already been initialized. -- trying to decode all loaded
+    // bytes.
+    rv = DecodeRawData(aData, aDataLength, /* aEndOfStream = */ false);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // If SRI is required for this load, appending new bytes to the hash.
+    if (mSRIDataVerifier && NS_SUCCEEDED(mSRIStatus)) {
+      mSRIStatus = mSRIDataVerifier->Update(aDataLength, aData);
+    }
+  } else if (mRequest->IsBinASTSource()) {
+    if (!mRequest->ScriptBinASTData().append(aData, aDataLength)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    // Below we will/shall consume entire data chunk.
+    *aConsumedLength = aDataLength;
+
+    // If SRI is required for this load, appending new bytes to the hash.
+    if (mSRIDataVerifier && NS_SUCCEEDED(mSRIStatus)) {
+      mSRIStatus = mSRIDataVerifier->Update(aDataLength, aData);
+    }
+  } else {
+    MOZ_ASSERT(mRequest->IsBytecode());
+    if (!mRequest->mScriptBytecode.append(aData, aDataLength)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    *aConsumedLength = aDataLength;
+    uint32_t sriLength = 0;
+    rv = MaybeDecodeSRI(&sriLength);
+    if (NS_FAILED(rv)) {
+      return channelRequest->Cancel(mScriptLoader->RestartLoad(mRequest));
+    }
+    if (sriLength) {
+      mRequest->mBytecodeOffset = JS::AlignTranscodingBytecodeOffset(sriLength);
+    }
+  }
+
+  return rv;
+}
+
+bool ScriptLoadHandler::TrySetDecoder(nsIIncrementalStreamLoader* aLoader,
+                                      const uint8_t* aData,
+                                      uint32_t aDataLength, bool aEndOfStream) {
+  MOZ_ASSERT(mDecoder == nullptr,
+             "can't have a decoder already if we're trying to set one");
+
+  // JavaScript modules are always UTF-8.
+  if (mRequest->IsModuleRequest()) {
+    mDecoder = UTF_8_ENCODING->NewDecoderWithBOMRemoval();
+    return true;
+  }
+
+  // Determine if BOM check should be done.  This occurs either
+  // if end-of-stream has been reached, or at least 3 bytes have
+  // been read from input.
+  if (!aEndOfStream && (aDataLength < 3)) {
+    return false;
+  }
+
+  // Do BOM detection.
+  const Encoding* encoding;
+  size_t bomLength;
+  Tie(encoding, bomLength) = Encoding::ForBOM(Span(aData, aDataLength));
+  if (encoding) {
+    mDecoder = encoding->NewDecoderWithBOMRemoval();
+    return true;
+  }
+
+  // BOM detection failed, check content stream for charset.
+  nsCOMPtr<nsIRequest> req;
+  nsresult rv = aLoader->GetRequest(getter_AddRefs(req));
+  NS_ASSERTION(req, "StreamLoader's request went away prematurely");
+  NS_ENSURE_SUCCESS(rv, false);
+
+  nsCOMPtr<nsIChannel> channel = do_QueryInterface(req);
+
+  if (channel) {
+    nsAutoCString label;
+    if (NS_SUCCEEDED(channel->GetContentCharset(label)) &&
+        (encoding = Encoding::ForLabel(label))) {
+      mDecoder = encoding->NewDecoderWithoutBOMHandling();
+      return true;
+    }
+  }
+
+  // Check the hint charset from the script element or preload
+  // request.
+  nsAutoString hintCharset;
+  if (!mRequest->IsPreload()) {
+    mRequest->GetScriptElement()->GetScriptCharset(hintCharset);
+  } else {
+    nsTArray<ScriptLoader::PreloadInfo>::index_type i =
+        mScriptLoader->mPreloads.IndexOf(
+            mRequest, 0, ScriptLoader::PreloadRequestComparator());
+
+    NS_ASSERTION(i != mScriptLoader->mPreloads.NoIndex,
+                 "Incorrect preload bookkeeping");
+    hintCharset = mScriptLoader->mPreloads[i].mCharset;
+  }
+
+  if ((encoding = Encoding::ForLabel(hintCharset))) {
+    mDecoder = encoding->NewDecoderWithoutBOMHandling();
+    return true;
+  }
+
+  // Get the charset from the charset of the document.
+  if (mScriptLoader->mDocument) {
+    encoding = mScriptLoader->mDocument->GetDocumentCharacterSet();
+    mDecoder = encoding->NewDecoderWithoutBOMHandling();
+    return true;
+  }
+
+  // Curiously, there are various callers that don't pass aDocument. The
+  // fallback in the old code was ISO-8859-1, which behaved like
+  // windows-1252.
+  mDecoder = WINDOWS_1252_ENCODING->NewDecoderWithoutBOMHandling();
+  return true;
+}
+
+nsresult ScriptLoadHandler::MaybeDecodeSRI(uint32_t* sriLength) {
+  *sriLength = 0;
+
+  if (!mSRIDataVerifier || mSRIDataVerifier->IsComplete() ||
+      NS_FAILED(mSRIStatus)) {
+    return NS_OK;
+  }
+
+  // Skip until the content is large enough to be decoded.
+  if (mRequest->mScriptBytecode.length() <=
+      mSRIDataVerifier->DataSummaryLength()) {
+    return NS_OK;
+  }
+
+  mSRIStatus = mSRIDataVerifier->ImportDataSummary(
+      mRequest->mScriptBytecode.length(), mRequest->mScriptBytecode.begin());
+
+  if (NS_FAILED(mSRIStatus)) {
+    // We are unable to decode the hash contained in the alternate data which
+    // contains the bytecode, or it does not use the same algorithm.
+    LOG(
+        ("ScriptLoadHandler::MaybeDecodeSRI, failed to decode SRI, restart "
+         "request"));
+    return mSRIStatus;
+  }
+
+  *sriLength = mSRIDataVerifier->DataSummaryLength();
+  MOZ_ASSERT(*sriLength > 0);
+  return NS_OK;
+}
+
+nsresult ScriptLoadHandler::EnsureKnownDataType(
+    nsIIncrementalStreamLoader* aLoader) {
+  MOZ_ASSERT(mRequest->IsUnknownDataType());
+  MOZ_ASSERT(mRequest->IsLoading());
+
+  nsCOMPtr<nsIRequest> req;
+  nsresult rv = aLoader->GetRequest(getter_AddRefs(req));
+  MOZ_ASSERT(req, "StreamLoader's request went away prematurely");
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mRequest->IsLoadingSource()) {
+    mRequest->SetTextSource();
+    TRACE_FOR_TEST(mRequest->GetScriptElement(), "scriptloader_load_source");
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsICacheInfoChannel> cic(do_QueryInterface(req));
+  if (cic) {
+    nsAutoCString altDataType;
+    cic->GetAlternativeDataType(altDataType);
+    if (altDataType.Equals(nsContentUtils::JSBytecodeMimeType())) {
+      mRequest->SetBytecode();
+      TRACE_FOR_TEST(mRequest->GetScriptElement(),
+                     "scriptloader_load_bytecode");
+      return NS_OK;
+    }
+    MOZ_ASSERT(altDataType.IsEmpty());
+  }
+
+  if (nsJSUtils::BinASTEncodingEnabled()) {
+    nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(req);
+    if (httpChannel) {
+      nsAutoCString mimeType;
+      httpChannel->GetContentType(mimeType);
+      if (mimeType.LowerCaseEqualsASCII(APPLICATION_JAVASCRIPT_BINAST)) {
+        if (mRequest->ShouldAcceptBinASTEncoding()) {
+          mRequest->SetBinASTSource();
+          TRACE_FOR_TEST(mRequest->GetScriptElement(),
+                         "scriptloader_load_source");
+          return NS_OK;
+        }
+
+        // If the request isn't allowed to accept BinAST, fallback to text
+        // source.  The possibly binary source will be passed to normal
+        // JS parser and will throw error there.
+        mRequest->SetTextSource();
+        return NS_OK;
+      }
+    }
+  }
+
+  mRequest->SetTextSource();
+  TRACE_FOR_TEST(mRequest->GetScriptElement(), "scriptloader_load_source");
+
+  MOZ_ASSERT(!mRequest->IsUnknownDataType());
+  MOZ_ASSERT(mRequest->IsLoading());
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ScriptLoadHandler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
+                                    nsISupports* aContext, nsresult aStatus,
+                                    uint32_t aDataLength,
+                                    const uint8_t* aData) {
+  nsresult rv = NS_OK;
+  if (LOG_ENABLED()) {
+    nsAutoCString url;
+    mRequest->mURI->GetAsciiSpec(url);
+    LOG(("ScriptLoadRequest (%p): Stream complete (url = %s)", mRequest.get(),
+         url.get()));
+  }
+
+  nsCOMPtr<nsIRequest> channelRequest;
+  aLoader->GetRequest(getter_AddRefs(channelRequest));
+
+  if (!mPreloadStartNotified) {
+    mPreloadStartNotified = true;
+    mRequest->NotifyStart(channelRequest);
+  }
+
+  auto notifyStop =
+      MakeScopeExit([&] { mRequest->NotifyStop(channelRequest, rv); });
+
+  if (!mRequest->IsCanceled()) {
+    if (mRequest->IsUnknownDataType()) {
+      rv = EnsureKnownDataType(aLoader);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    if (mRequest->IsTextSource()) {
+      DebugOnly<bool> encoderSet =
+          EnsureDecoder(aLoader, aData, aDataLength, /* aEndOfStream = */ true);
+      MOZ_ASSERT(encoderSet);
+      rv = DecodeRawData(aData, aDataLength, /* aEndOfStream = */ true);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      LOG(("ScriptLoadRequest (%p): Source length in code units = %u",
+           mRequest.get(), unsigned(mRequest->ScriptTextLength())));
+
+      // If SRI is required for this load, appending new bytes to the hash.
+      if (mSRIDataVerifier && NS_SUCCEEDED(mSRIStatus)) {
+        mSRIStatus = mSRIDataVerifier->Update(aDataLength, aData);
+      }
+    } else if (mRequest->IsBinASTSource()) {
+      if (!mRequest->ScriptBinASTData().append(aData, aDataLength)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      // If SRI is required for this load, appending new bytes to the hash.
+      if (mSRIDataVerifier && NS_SUCCEEDED(mSRIStatus)) {
+        mSRIStatus = mSRIDataVerifier->Update(aDataLength, aData);
+      }
+    } else {
+      MOZ_ASSERT(mRequest->IsBytecode());
+      if (!mRequest->mScriptBytecode.append(aData, aDataLength)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      LOG(("ScriptLoadRequest (%p): Bytecode length = %u", mRequest.get(),
+           unsigned(mRequest->mScriptBytecode.length())));
+
+      // If we abort while decoding the SRI, we fallback on explictly requesting
+      // the source. Thus, we should not continue in
+      // ScriptLoader::OnStreamComplete, which removes the request from the
+      // waiting lists.
+      //
+      // We calculate the SRI length below.
+      uint32_t unused;
+      rv = MaybeDecodeSRI(&unused);
+      if (NS_FAILED(rv)) {
+        return channelRequest->Cancel(mScriptLoader->RestartLoad(mRequest));
+      }
+
+      // The bytecode cache always starts with the SRI hash, thus even if there
+      // is no SRI data verifier instance, we still want to skip the hash.
+      uint32_t sriLength;
+      rv = SRICheckDataVerifier::DataSummaryLength(
+          mRequest->mScriptBytecode.length(), mRequest->mScriptBytecode.begin(),
+          &sriLength);
+      if (NS_FAILED(rv)) {
+        return channelRequest->Cancel(mScriptLoader->RestartLoad(mRequest));
+      }
+
+      mRequest->mBytecodeOffset = JS::AlignTranscodingBytecodeOffset(sriLength);
+    }
+  }
+
+  // Everything went well, keep the CacheInfoChannel alive such that we can
+  // later save the bytecode on the cache entry.
+  if (NS_SUCCEEDED(rv) && mRequest->IsSource() &&
+      StaticPrefs::dom_script_loader_bytecode_cache_enabled()) {
+    mRequest->mCacheInfo = do_QueryInterface(channelRequest);
+    LOG(("ScriptLoadRequest (%p): nsICacheInfoChannel = %p", mRequest.get(),
+         mRequest->mCacheInfo.get()));
+  }
+
+  // we have to mediate and use mRequest.
+  rv = mScriptLoader->OnStreamComplete(aLoader, mRequest, aStatus, mSRIStatus,
+                                       mSRIDataVerifier.get());
+
+  // In case of failure, clear the mCacheInfoChannel to avoid keeping it alive.
+  if (NS_FAILED(rv)) {
+    mRequest->mCacheInfo = nullptr;
+  }
+
+  return rv;
+}
+
+#undef LOG_ENABLED
+#undef LOG
+
+}  // namespace dom
+}  // namespace mozilla