Refactored the PPB_Flash_File_ModuleLocal/FileRef to the new ppapi resource model

content/browser/renderer_host/pepper/pepper_flash_file_host.cc

+// 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 "content/browser/renderer_host/pepper/pepper_flash_file_host.h"
+
+#include "base/bind.h"
+#include "base/file_util.h"
+#include "base/task_runner.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "content/browser/child_process_security_policy_impl.h"
+#include "content/public/browser/browser_ppapi_host.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/common/content_constants.h"
+#include "ipc/ipc_platform_file.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/host/dispatch_host_message.h"
+#include "ppapi/host/host_message_context.h"
+#include "ppapi/host/ppapi_host.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/shared_impl/file_path.h"
+#include "ppapi/shared_impl/file_type_conversion.h"
+
+namespace content {
+
+namespace {
+// Used to check if the renderer has permission for the requested operation.
+// TODO(viettrungluu): Verify these. They don't necessarily quite make sense,
+// but it seems to be approximately what the file system code does.
+const int kReadPermissions = base::PLATFORM_FILE_OPEN |
+                             base::PLATFORM_FILE_READ |
+                             base::PLATFORM_FILE_EXCLUSIVE_READ;
+const int kWritePermissions = base::PLATFORM_FILE_OPEN |
+                              base::PLATFORM_FILE_CREATE |
+                              base::PLATFORM_FILE_CREATE_ALWAYS |
+                              base::PLATFORM_FILE_OPEN_TRUNCATED |
+                              base::PLATFORM_FILE_WRITE |
+                              base::PLATFORM_FILE_EXCLUSIVE_WRITE |
+                              base::PLATFORM_FILE_WRITE_ATTRIBUTES;
+
+// All file messages are handled by BrowserThread's blocking pool.
+class FileMessageFilter : public ppapi::host::ResourceMessageFilter {
+ public:
+  FileMessageFilter(const std::string& plugin_name,
+                    const FilePath& profile_data_directory,
+                    int render_process_id,
+                    base::ProcessHandle plugin_process_handle);
+ protected:
+  // ppapi::host::ResourceMessageFilter implementation.
+  virtual scoped_refptr<base::TaskRunner> OverrideTaskRunnerForMessage(
+      const IPC::Message& msg) OVERRIDE;
+  virtual int32_t OnResourceMessageReceived(
+      const IPC::Message& msg,
+      ppapi::host::HostMessageContext* context) OVERRIDE;
+
+ private:
+  virtual ~FileMessageFilter();
+
+  int32_t OnOpenFile(ppapi::host::HostMessageContext* context,
+                     const ppapi::PepperFilePath& path,
+                     int flags);
+  int32_t OnRenameFile(ppapi::host::HostMessageContext* context,
+                       const ppapi::PepperFilePath& from_path,
+                       const ppapi::PepperFilePath& to_path);
+  int32_t OnDeleteFileOrDir(ppapi::host::HostMessageContext* context,
+                            const ppapi::PepperFilePath& path,
+                            bool recursive);
+  int32_t OnCreateDir(ppapi::host::HostMessageContext* context,
+                      const ppapi::PepperFilePath& path);
+  int32_t OnQueryFile(ppapi::host::HostMessageContext* context,
+                      const ppapi::PepperFilePath& path);
+  int32_t OnGetDirContents(ppapi::host::HostMessageContext* context,
+                           const ppapi::PepperFilePath& path);
+  int32_t OnCreateTemporaryFile(ppapi::host::HostMessageContext* context);
+
+  FilePath ValidateAndConvertPepperFilePath(
+      const ppapi::PepperFilePath& pepper_path,
+      int flags);
+
+  FilePath plugin_data_directory_;
+  int render_process_id_;
+  base::ProcessHandle plugin_process_handle_;
+};
+
+FileMessageFilter::FileMessageFilter(
+    const std::string& plugin_name,
+    const FilePath& profile_data_directory,
+    int render_process_id,
+    base::ProcessHandle plugin_process_handle)
+    : render_process_id_(render_process_id),
+      plugin_process_handle_(plugin_process_handle) {
+  if (profile_data_directory.empty() || plugin_name.empty()) {
+    // These are used to construct the path. If they are not set it means we
+    // will construct a bad path and could provide access to the wrong files.
+    // In this case, |plugin_data_directory_| will remain unset and
+    // |ValidateAndConvertPepperFilePath| will fail.
+    NOTREACHED();
+  } else {
+    plugin_data_directory_ = PepperFlashFileHost::GetDataDirName(
+        profile_data_directory).Append(FilePath::FromUTF8Unsafe(plugin_name));
+  }
+}
+
+FileMessageFilter::~FileMessageFilter() {
+}
+
+scoped_refptr<base::TaskRunner>
+FileMessageFilter::OverrideTaskRunnerForMessage(const IPC::Message& msg) {
+  // The blocking pool provides a pool of threads to run file
+  // operations, instead of a single thread which might require
+  // queuing time.  Since these messages are synchronous as sent from
+  // the plugin, the sending thread cannot send a new message until
+  // this one returns, so there is no need to sequence tasks here.  If
+  // the plugin has multiple threads, it cannot make assumptions about
+  // ordering of IPC message sends, so it cannot make assumptions
+  // about ordering of operations caused by those IPC messages.
+  return scoped_refptr<base::TaskRunner>(BrowserThread::GetBlockingPool());
+}
+
+int32_t FileMessageFilter::OnResourceMessageReceived(
+   const IPC::Message& msg,
+   ppapi::host::HostMessageContext* context) {
+  IPC_BEGIN_MESSAGE_MAP(FileMessageFilter, msg)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_FlashFile_OpenFile,
+                                      OnOpenFile)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_FlashFile_RenameFile,
+                                      OnRenameFile)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_FlashFile_DeleteFileOrDir,
+                                      OnDeleteFileOrDir)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_FlashFile_CreateDir,
+                                      OnCreateDir)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_FlashFile_QueryFile,
+                                      OnQueryFile)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_FlashFile_GetDirContents,
+                                      OnGetDirContents)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
+        PpapiHostMsg_FlashFile_CreateTemporaryFile,
+        OnCreateTemporaryFile)
+  IPC_END_MESSAGE_MAP()
+  return PP_ERROR_FAILED;
+}
+
+int32_t FileMessageFilter::OnOpenFile(
+    ppapi::host::HostMessageContext* context,
+    const ppapi::PepperFilePath& path,
+    int flags) {
+  FilePath full_path = ValidateAndConvertPepperFilePath(path, flags);
+  if (full_path.empty()) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  base::PlatformFileError error = base::PLATFORM_FILE_ERROR_FAILED;
+  base::PlatformFile file_handle = base::CreatePlatformFile(
+      full_path, flags, NULL, &error);
+  if (error != base::PLATFORM_FILE_OK) {
+    DCHECK_EQ(file_handle, base::kInvalidPlatformFileValue);
+    return ppapi::PlatformFileErrorToPepperError(error);
+  }
+
+  // Make sure we didn't try to open a directory: directory fd shouldn't be
+  // passed to untrusted processes because they open security holes.
+  base::PlatformFileInfo info;
+  if (!base::GetPlatformFileInfo(file_handle, &info) || info.is_directory) {
+    // When in doubt, throw it out.
+    base::ClosePlatformFile(file_handle);
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  IPC::PlatformFileForTransit file = IPC::GetFileHandleForProcess(file_handle,
+      plugin_process_handle_, true);
+  ppapi::host::ReplyMessageContext reply_context =
+      context->MakeReplyMessageContext();
+  reply_context.params.AppendHandle(ppapi::proxy::SerializedHandle(
+      ppapi::proxy::SerializedHandle::FILE, file));
+  SendReply(reply_context, IPC::Message());
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t FileMessageFilter::OnRenameFile(
+    ppapi::host::HostMessageContext* context,
+    const ppapi::PepperFilePath& from_path,
+    const ppapi::PepperFilePath& to_path) {
+  FilePath from_full_path = ValidateAndConvertPepperFilePath(from_path,
+                                                             kWritePermissions);
+  FilePath to_full_path = ValidateAndConvertPepperFilePath(to_path,
+                                                           kWritePermissions);
+  if (from_full_path.empty() || to_full_path.empty()) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  bool result = file_util::Move(from_full_path, to_full_path);
+  return ppapi::PlatformFileErrorToPepperError(result ?
+      base::PLATFORM_FILE_OK : base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+}
+
+int32_t FileMessageFilter::OnDeleteFileOrDir(
+    ppapi::host::HostMessageContext* context,
+    const ppapi::PepperFilePath& path,
+    bool recursive) {
+  FilePath full_path = ValidateAndConvertPepperFilePath(path,
+                                                        kWritePermissions);
+  if (full_path.empty()) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  bool result = file_util::Delete(full_path, recursive);
+  return ppapi::PlatformFileErrorToPepperError(result ?
+      base::PLATFORM_FILE_OK : base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+}
+int32_t FileMessageFilter::OnCreateDir(
+    ppapi::host::HostMessageContext* context,
+    const ppapi::PepperFilePath& path) {
+  FilePath full_path = ValidateAndConvertPepperFilePath(path,
+                                                        kWritePermissions);
+  if (full_path.empty()) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  bool result = file_util::CreateDirectory(full_path);
+  return ppapi::PlatformFileErrorToPepperError(result ?
+      base::PLATFORM_FILE_OK : base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+}
+
+int32_t FileMessageFilter::OnQueryFile(
+    ppapi::host::HostMessageContext* context,
+    const ppapi::PepperFilePath& path) {
+  FilePath full_path = ValidateAndConvertPepperFilePath(path,
+                                                        kReadPermissions);
+  if (full_path.empty()) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  base::PlatformFileInfo info;
+  bool result = file_util::GetFileInfo(full_path, &info);
+  context->reply_msg = PpapiPluginMsg_FlashFile_QueryFileReply(info);
+  return ppapi::PlatformFileErrorToPepperError(result ?
+      base::PLATFORM_FILE_OK : base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+}
+
+int32_t FileMessageFilter::OnGetDirContents(
+    ppapi::host::HostMessageContext* context,
+    const ppapi::PepperFilePath& path) {
+  FilePath full_path = ValidateAndConvertPepperFilePath(path, kReadPermissions);
+  if (full_path.empty()) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  ppapi::DirContents contents;
+  file_util::FileEnumerator enumerator(full_path, false,
+      file_util::FileEnumerator::FILES |
+      file_util::FileEnumerator::DIRECTORIES |
+      file_util::FileEnumerator::INCLUDE_DOT_DOT);
+
+  while (!enumerator.Next().empty()) {
+    file_util::FileEnumerator::FindInfo info;
+    enumerator.GetFindInfo(&info);
+    ppapi::DirEntry entry = {
+      file_util::FileEnumerator::GetFilename(info),
+      file_util::FileEnumerator::IsDirectory(info)
+    };
+    contents.push_back(entry);
+  }
+
+  context->reply_msg = PpapiPluginMsg_FlashFile_GetDirContentsReply(contents);
+  return PP_OK;
+}
+
+int32_t FileMessageFilter::OnCreateTemporaryFile(
+    ppapi::host::HostMessageContext* context) {
+  ppapi::PepperFilePath dir_path(
+      ppapi::PepperFilePath::DOMAIN_MODULE_LOCAL, FilePath());
+  FilePath validated_dir_path = ValidateAndConvertPepperFilePath(
+      dir_path, kReadPermissions | kWritePermissions);
+  if (validated_dir_path.empty() ||
+      (!file_util::DirectoryExists(validated_dir_path) &&
+       !file_util::CreateDirectory(validated_dir_path))) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_ACCESS_DENIED);
+  }
+
+  FilePath file_path;
+  if (!file_util::CreateTemporaryFileInDir(validated_dir_path, &file_path)) {
+    return ppapi::PlatformFileErrorToPepperError(
+        base::PLATFORM_FILE_ERROR_FAILED);
+  }
+
+  base::PlatformFileError error = base::PLATFORM_FILE_ERROR_FAILED;
+  base::PlatformFile file_handle = base::CreatePlatformFile(
+      file_path,
+      base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_READ |
+      base::PLATFORM_FILE_WRITE | base::PLATFORM_FILE_TEMPORARY |
+      base::PLATFORM_FILE_DELETE_ON_CLOSE,
+      NULL, &error);
+
+  if (error != base::PLATFORM_FILE_OK) {
+    DCHECK_EQ(file_handle, base::kInvalidPlatformFileValue);
+    return ppapi::PlatformFileErrorToPepperError(error);
+  }
+
+  IPC::PlatformFileForTransit file = IPC::GetFileHandleForProcess(file_handle,
+      plugin_process_handle_, true);
+  ppapi::host::ReplyMessageContext reply_context =
+      context->MakeReplyMessageContext();
+  reply_context.params.AppendHandle(ppapi::proxy::SerializedHandle(
+      ppapi::proxy::SerializedHandle::FILE, file));
+  SendReply(reply_context, IPC::Message());
+  return PP_OK_COMPLETIONPENDING;
+}
+
+FilePath FileMessageFilter::ValidateAndConvertPepperFilePath(
+    const ppapi::PepperFilePath& pepper_path,
+    int flags) {
+  FilePath file_path;  // Empty path returned on error.
+  switch (pepper_path.domain()) {
+    case ppapi::PepperFilePath::DOMAIN_ABSOLUTE:
+      if (pepper_path.path().IsAbsolute() &&
+          ChildProcessSecurityPolicyImpl::GetInstance()->HasPermissionsForFile(
+              render_process_id_, pepper_path.path(), flags))
+        file_path = pepper_path.path();
+      break;
+    case ppapi::PepperFilePath::DOMAIN_MODULE_LOCAL:
+      // This filter provides the module name portion of the path to prevent
+      // plugins from accessing each other's data.
+      if (!plugin_data_directory_.empty() &&
+          !pepper_path.path().IsAbsolute() &&
+          !pepper_path.path().ReferencesParent())
+        file_path = plugin_data_directory_.Append(pepper_path.path());
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+  return file_path;
+}
+
+}  // namespace
+
+PepperFlashFileHost::PepperFlashFileHost(
+    BrowserPpapiHost* host,
+    PP_Instance instance,
+    PP_Resource resource)
+    : ResourceHost(host->GetPpapiHost(), instance, resource) {
+  int render_process_id, unused;
+  host->GetRenderViewIDsForInstance(instance, &render_process_id, &unused);
+  AddFilter(scoped_refptr<ppapi::host::ResourceMessageFilter>(
+      new FileMessageFilter(host->GetPluginName(),
+                            host->GetProfileDataDirectory(),
+                            render_process_id,
+                            host->GetPluginProcessHandle())));
+}
+
+PepperFlashFileHost::~PepperFlashFileHost() {
+}
+
+// static
+FilePath PepperFlashFileHost::GetDataDirName(const FilePath& profile_path) {
+  return profile_path.Append(kPepperDataDirname);
+}
+
+}  // namespace content