diff -r 000000000000 -r 6474c204b198 dom/filesystem/DeviceStorageFileSystem.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/filesystem/DeviceStorageFileSystem.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,188 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* vim: set ts=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/DeviceStorageFileSystem.h"
+
+#include "DeviceStorage.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsDeviceStorage.h"
+#include "nsIDOMFile.h"
+#include "nsIFile.h"
+#include "nsPIDOMWindow.h"
+
+namespace mozilla {
+namespace dom {
+
+DeviceStorageFileSystem::DeviceStorageFileSystem(
+  const nsAString& aStorageType,
+  const nsAString& aStorageName)
+  : mDeviceStorage(nullptr)
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+
+  mStorageType = aStorageType;
+  mStorageName = aStorageName;
+
+  // Generate the string representation of the file system.
+  mString.AppendLiteral("devicestorage-");
+  mString.Append(mStorageType);
+  mString.AppendLiteral("-");
+  mString.Append(mStorageName);
+
+  mIsTesting =
+    mozilla::Preferences::GetBool("device.storage.prompt.testing", false);
+
+  // Get the permission name required to access the file system.
+  nsresult rv =
+    DeviceStorageTypeChecker::GetPermissionForType(mStorageType, mPermission);
+  NS_WARN_IF(NS_FAILED(rv));
+
+  // Get the local path of the file system root.
+  // Since the child process is not allowed to access the file system, we only
+  // do this from the parent process.
+  if (!FileSystemUtils::IsParentProcess()) {
+    return;
+  }
+  nsCOMPtr<nsIFile> rootFile;
+  DeviceStorageFile::GetRootDirectoryForType(aStorageType,
+                                             aStorageName,
+                                             getter_AddRefs(rootFile));
+
+  NS_WARN_IF(!rootFile || NS_FAILED(rootFile->GetPath(mLocalRootPath)));
+  FileSystemUtils::LocalPathToNormalizedPath(mLocalRootPath,
+    mNormalizedLocalRootPath);
+
+  // DeviceStorageTypeChecker is a singleton object and must be initialized on
+  // the main thread. We initialize it here so that we can use it on the worker
+  // thread.
+  DebugOnly<DeviceStorageTypeChecker*> typeChecker
+    = DeviceStorageTypeChecker::CreateOrGet();
+  MOZ_ASSERT(typeChecker);
+}
+
+DeviceStorageFileSystem::~DeviceStorageFileSystem()
+{
+}
+
+void
+DeviceStorageFileSystem::Init(nsDOMDeviceStorage* aDeviceStorage)
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  MOZ_ASSERT(aDeviceStorage);
+  mDeviceStorage = aDeviceStorage;
+}
+
+void
+DeviceStorageFileSystem::Shutdown()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  mDeviceStorage = nullptr;
+  mShutdown = true;
+}
+
+nsPIDOMWindow*
+DeviceStorageFileSystem::GetWindow() const
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  if (!mDeviceStorage) {
+    return nullptr;
+  }
+  return mDeviceStorage->GetOwner();
+}
+
+already_AddRefed<nsIFile>
+DeviceStorageFileSystem::GetLocalFile(const nsAString& aRealPath) const
+{
+  MOZ_ASSERT(FileSystemUtils::IsParentProcess(),
+             "Should be on parent process!");
+  nsAutoString localPath;
+  FileSystemUtils::NormalizedPathToLocalPath(aRealPath, localPath);
+  localPath = mLocalRootPath + localPath;
+  nsCOMPtr<nsIFile> file;
+  nsresult rv = NS_NewLocalFile(localPath, false, getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+  return file.forget();
+}
+
+bool
+DeviceStorageFileSystem::GetRealPath(nsIDOMFile* aFile, nsAString& aRealPath) const
+{
+  MOZ_ASSERT(FileSystemUtils::IsParentProcess(),
+             "Should be on parent process!");
+  MOZ_ASSERT(aFile, "aFile Should not be null.");
+
+  aRealPath.Truncate();
+
+  nsAutoString filePath;
+  if (NS_FAILED(aFile->GetMozFullPathInternal(filePath))) {
+    return false;
+  }
+
+  return LocalPathToRealPath(filePath, aRealPath);
+}
+
+const nsAString&
+DeviceStorageFileSystem::GetRootName() const
+{
+  return mStorageName;
+}
+
+bool
+DeviceStorageFileSystem::IsSafeFile(nsIFile* aFile) const
+{
+  MOZ_ASSERT(FileSystemUtils::IsParentProcess(),
+             "Should be on parent process!");
+  MOZ_ASSERT(aFile);
+
+  // Check if this file belongs to this storage.
+  nsAutoString path;
+  if (NS_FAILED(aFile->GetPath(path))) {
+    return false;
+  }
+  if (!LocalPathToRealPath(path, path)) {
+    return false;
+  }
+
+  // Check if the file type is compatible with the storage type.
+  DeviceStorageTypeChecker* typeChecker
+    = DeviceStorageTypeChecker::CreateOrGet();
+  MOZ_ASSERT(typeChecker);
+  return typeChecker->Check(mStorageType, aFile);
+}
+
+bool
+DeviceStorageFileSystem::IsSafeDirectory(Directory* aDir) const
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  MOZ_ASSERT(aDir);
+  nsRefPtr<FileSystemBase> fs = aDir->GetFileSystem();
+  MOZ_ASSERT(fs);
+  // Check if the given directory is from this storage.
+  return fs->ToString() == mString;
+}
+
+bool
+DeviceStorageFileSystem::LocalPathToRealPath(const nsAString& aLocalPath,
+                                             nsAString& aRealPath) const
+{
+  nsAutoString path;
+  FileSystemUtils::LocalPathToNormalizedPath(aLocalPath, path);
+  if (!FileSystemUtils::IsDescendantPath(mNormalizedLocalRootPath, path)) {
+    aRealPath.Truncate();
+    return false;
+  }
+  aRealPath = Substring(path, mNormalizedLocalRootPath.Length());
+  return true;
+}
+
+} // namespace dom
+} // namespace mozilla