Native Messaging!

chrome/browser/extensions/api/native_message/native_message_api.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 "chrome/browser/extensions/api/native_message/native_message_api.h"
+
+#include "base/bind.h"
+#include "base/command_line.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/path_service.h"
+#include "base/threading/simple_thread.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/api/native_message/native_thread_delegate.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/common/chrome_switches.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace {
+
+const char kNativeClientDir[] = "native-hosts";

[Matt Perry, 2012/07/23 23:47:03]

Chrome's data directories are formatted like "Native Hosts"

+
+}  // namespace
+
+SendNativeMessageFunction::SendNativeMessageFunction() {}
+
+SendNativeMessageFunction::~SendNativeMessageFunction() {
+}
+
+void SendNativeMessageFunction::SendResponseOnUIThread(
+    bool success, scoped_ptr<std::string> error,
+    scoped_ptr<DictionaryValue> result) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  if (error.get() && !error->empty()) {
+    CHECK(!success);
+    SetError(*error.get());
+    LOG(ERROR) << *error;
+  }
+  if (success) {
+    SetResult(result->DeepCopy());
+  }
+  SendResponse(success);
+
+  content::BrowserThread::PostBlockingPoolTask(
+      FROM_HERE,
+      base::Bind(&SendNativeMessageFunction::JoinThreadOnBackgroundThread,
+                 this));
+}
+
+bool SendNativeMessageFunction::RunImpl() {
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(

[Aaron Boodman, 2012/07/23 22:30:17]

Can you also make this only work on the dev channel for now? See
http://code.google.com/searchframe#OAMlx_jo-ck/src/chrome/common/extensions/f...
for how to check this.

[Matt Perry, 2012/07/23 23:47:03]

Wouldn't it just be a matter of adding extension.sendNativeMessage to
_permission_features.json?

+      switches::kEnableNativeMessaging))
+    return false;
+
+  DictionaryValue* data;
+  std::string native_app_name;
+  // TODO(eriq): There is nothing to prevent the user from pathing away from the
+  // intended directory. Eg. '../../dangerous_something.exe'.

[Aaron Boodman, 2012/07/23 22:30:17]

Good point. You can easily defend against that by using
file_util::ContainsPath().

+  EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &native_app_name));
+  // args_ maintains ownership of |data|, it is safe to pass by reference.
+  EXTENSION_FUNCTION_VALIDATE(args_->GetDictionary(1, &data));
+
+  FilePath path;
+  CHECK(PathService::Get(chrome::DIR_USER_DATA, &path));
+  path = path.Append(kNativeClientDir);
+  path = path.Append(native_app_name);
+
+  thread_delegate_.reset(new NativeThreadDelegate(
+      data, scoped_ptr<FilePath>(new FilePath(path)),
+      base::Bind(&SendNativeMessageFunction::SendResponseOnUIThread,
+                 this)));
+  thread_.reset(new base::DelegateSimpleThread(thread_delegate_.get(),
+                "test_prefix"));

[Matt Perry, 2012/07/23 23:47:03]

Have you seen base::WorkerPool? It might be better than allocating a separate
dedicated thread for each message.

+  thread_->Start();
+
+  return true;
+}
+
+void SendNativeMessageFunction::JoinThreadOnBackgroundThread() {
+  CHECK(!content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  thread_->Join();
+}