1 files changed, 81 insertions, 0 deletions
diff --git a/dom/ipc/JSValidatorChild.cpp b/dom/ipc/JSValidatorChild.cpp
new file mode 100644
index 0000000000..3353eb11ff
--- /dev/null
+++ b/dom/ipc/JSValidatorChild.cpp
@@ -0,0 +1,81 @@
+/* -*- 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/dom/JSValidatorChild.h"
+#include "mozilla/ipc/Endpoint.h"
+
+using namespace mozilla::dom;
+
+mozilla::ipc::IPCResult JSValidatorChild::RecvIsOpaqueResponseAllowed(
+    IsOpaqueResponseAllowedResolver&& aResolver) {
+  mResolver.emplace(aResolver);
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult JSValidatorChild::RecvOnDataAvailable(Shmem&& aData) {
+  MOZ_ASSERT(mResolver);
+
+  if (!mSourceBytes.Append(Span(aData.get<char>(), aData.Size<char>()),
+                           mozilla::fallible)) {
+    // To prevent an attacker from flood the validation process,
+    // we don't validate here.
+    Resolve(false);
+  }
+  DeallocShmem(aData);
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult JSValidatorChild::RecvOnStopRequest(
+    const nsresult& aReason) {
+  if (!mResolver) {
+    return IPC_OK();
+  }
+
+  if (NS_FAILED(aReason)) {
+    Resolve(false);
+  } else {
+    Resolve(ShouldAllowJS());
+  }
+
+  return IPC_OK();
+}
+
+void JSValidatorChild::ActorDestroy(ActorDestroyReason aReason) {
+  if (mResolver) {
+    Resolve(false);
+  }
+};
+
+void JSValidatorChild::Resolve(bool aAllow) {
+  MOZ_ASSERT(mResolver);
+  Maybe<Shmem> data = Nothing();
+  if (aAllow) {
+    if (!mSourceBytes.IsEmpty()) {
+      Shmem sharedData;
+      nsresult rv =
+          JSValidatorUtils::CopyCStringToShmem(this, mSourceBytes, sharedData);
+      if (NS_SUCCEEDED(rv)) {
+        data = Some(std::move(sharedData));
+      }
+    }
+  }
+  mResolver.ref()(
+      Tuple<const bool&, mozilla::Maybe<Shmem>&&>(aAllow, std::move(data)));
+  mResolver = Nothing();
+}
+
+bool JSValidatorChild::ShouldAllowJS() const {
+  // mSourceBytes could be empty when
+  // 1. No OnDataAvailable calls
+  // 2. Failed to allocate shmem
+  //
+  // TODO(sefeng): THIS IS A VERY TEMPORARY SOLUTION
+  return !mSourceBytes.IsEmpty()
+             ? !StringBeginsWith(NS_ConvertUTF8toUTF16(mSourceBytes), u"{"_ns)
+             : true;
+}