Isolated FS for media devices.

webkit/fileapi/media/device_media_file_util.cc

Index: webkit/fileapi/media/device_media_file_util.cc
diff --git a/webkit/fileapi/media/device_media_file_util.cc b/webkit/fileapi/media/device_media_file_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..37b04a9061521f89401aeb42d50999e2eb73eea1
--- /dev/null
+++ b/webkit/fileapi/media/device_media_file_util.cc
@@ -0,0 +1,202 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "webkit/fileapi/media/device_media_file_util.h"
+
+#include "base/file_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop_proxy.h"
+#include "webkit/blob/shareable_file_reference.h"
+#include "webkit/fileapi/file_system_operation_context.h"
+#include "webkit/fileapi/file_system_url.h"
+#include "webkit/fileapi/isolated_context.h"
+#include "webkit/fileapi/media/media_device_interface_impl.h"
+#include "webkit/fileapi/media/media_device_map_service.h"
+
+using base::PlatformFileError;
+using base::PlatformFileInfo;
+using webkit_blob::ShareableFileReference;
+
+namespace fileapi {
+
+namespace {
+
+const FilePath::CharType kDeviceMediaFileUtilTempDir[] =
+    FILE_PATH_LITERAL("DeviceMediaFileSystem");
+
+}  // namespace
+
+DeviceMediaFileUtil::DeviceMediaFileUtil(const FilePath& profile_path)
+    : profile_path_(profile_path) {
+}
+
+PlatformFileError DeviceMediaFileUtil::CreateOrOpen(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url, int file_flags,
+    PlatformFile* file_handle, bool* created) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::Close(
+    FileSystemOperationContext* context,
+    PlatformFile file_handle) {
+  // We don't allow open thus Close won't be called.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::EnsureFileExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    bool* created) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::CreateDirectory(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    bool exclusive,
+    bool recursive) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::GetFileInfo(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    PlatformFileInfo* file_info,
+    FilePath* platform_path) {
+  if (!context->media_device())
+    return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+  return context->media_device()->GetFileInfo(url.path(), file_info);
+}
+
+FileSystemFileUtil::AbstractFileEnumerator*
+DeviceMediaFileUtil::CreateFileEnumerator(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    bool recursive) {
+  if (!context->media_device())
+    return new FileSystemFileUtil::EmptyFileEnumerator();
+  return context->media_device()->CreateFileEnumerator(url.path(), recursive);
+}
+
+PlatformFileError DeviceMediaFileUtil::GetLocalFilePath(
+    FileSystemOperationContext* context,
+    const FileSystemURL& file_system_url,
+    FilePath* local_file_path) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::Touch(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    const base::Time& last_access_time,
+    const base::Time& last_modified_time) {
+  if (!context->media_device())
+    return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+  return context->media_device()->Touch(url.path(), last_access_time,
+                                        last_modified_time);
+}
+
+PlatformFileError DeviceMediaFileUtil::Truncate(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    int64 length) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+bool DeviceMediaFileUtil::PathExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  if (!context->media_device())
+    return false;
+  return context->media_device()->PathExists(url.path());
+}
+
+bool DeviceMediaFileUtil::DirectoryExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  if (!context->media_device())
+    return false;
+  return context->media_device()->DirectoryExists(url.path());
+}
+
+bool DeviceMediaFileUtil::IsDirectoryEmpty(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  if (!context->media_device())
+    return false;
+  return context->media_device()->IsDirectoryEmpty(url.path());
+}
+
+PlatformFileError DeviceMediaFileUtil::CopyOrMoveFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& src_url,
+    const FileSystemURL& dest_url,
+    bool copy) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::CopyInForeignFile(
+    FileSystemOperationContext* context,
+    const FilePath& src_file_path,
+    const FileSystemURL& dest_url) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::DeleteFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::DeleteSingleDirectory(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+scoped_refptr<ShareableFileReference> DeviceMediaFileUtil::CreateSnapshotFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    base::PlatformFileError* result,
+    base::PlatformFileInfo* file_info,
+    FilePath* local_path) {
+  DCHECK(result);
+  DCHECK(file_info);
+  DCHECK(local_path);
+
+  scoped_refptr<ShareableFileReference> file_ref;
+  if (!context->media_device()) {
+    *result = base::PLATFORM_FILE_ERROR_NOT_FOUND;
+    return file_ref;
+  }
+
+  *result = base::PLATFORM_FILE_ERROR_FAILED;
+
+  // Create a temp file in "profile_path_/kDeviceMediaFileUtilTempDir".
+  FilePath isolated_media_file_system_dir_path =

[Lei Zhang, 2012/08/02 21:32:03]

I forgot to mention this problem because I hacked around it locally. At some
point, you need to grant permission to read the files in this directory.
Otherwise you'll fail the security check in
FileAPIMessageFilter::OnAppendBlobDataItem() and everything after that.

[kmadhusu, 2012/08/02 22:05:39]

kinuko@ is working on the fix.

[kinuko, 2012/08/13 16:41:03]

I believe this has been fixed after http://crrev.com/149798.
Apologies for not having cc'ed you.

[kmadhusu, 2012/08/13 16:43:06]

Np. Thanks for the info.

+      profile_path_.Append(kDeviceMediaFileUtilTempDir);
+  bool dir_exists = file_util::DirectoryExists(
+      isolated_media_file_system_dir_path);
+  if (!dir_exists) {
+    if (!file_util::CreateDirectory(isolated_media_file_system_dir_path))
+      return file_ref;
+  }
+
+  bool file_created = file_util::CreateTemporaryFileInDir(
+      isolated_media_file_system_dir_path, local_path);
+  if (!file_created)
+    return file_ref;
+
+  *result = context->media_device()->CreateSnapshotFile(url.path(), *local_path,
+                                                        file_info);
+  if (*result == base::PLATFORM_FILE_OK) {
+    file_ref = ShareableFileReference::GetOrCreate(
+        *local_path, ShareableFileReference::DELETE_ON_FINAL_RELEASE,
+        context->file_task_runner());
+  }
+  return file_ref;
+}
+
+}  // namespace fileapi