Accept inbound connections on unix domain socket

mojo/shell/external_application_registrar_connection.h

+// Copyright 2014 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.
+
+#ifndef MOJO_SHELL_EXTERNAL_APPLICATION_REGISTRAR_CONNECTION_H_
+#define MOJO_SHELL_EXTERNAL_APPLICATION_REGISTRAR_CONNECTION_H_
+
+#include "base/callback_forward.h"
+#include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
+#include "mojo/common/common_type_converters.h"
+#include "mojo/embedder/channel_init.h"
+#include "mojo/public/cpp/bindings/error_handler.h"
+#include "mojo/public/interfaces/application/application.mojom.h"
+#include "mojo/public/interfaces/application/shell.mojom.h"
+#include "mojo/shell/external_application_registrar.mojom.h"
+#include "net/socket/socket_descriptor.h"
+#include "net/socket/unix_domain_client_socket_posix.h"
+#include "url/gurl.h"
+
+namespace mojo {
+namespace shell {
+
+// Externally-running applications can use this class to discover and register
+// with a running mojo_shell instance.
+// MUST be run on an IO thread
+class ExternalApplicationRegistrarConnection : public ErrorHandler {
+ public:
+  // Configures client_socket_ to point at socket_path.
+  explicit ExternalApplicationRegistrarConnection(
+      const base::FilePath& socket_path);
+  virtual ~ExternalApplicationRegistrarConnection();
+
+  // Implementation of ErrorHandler
+  virtual void OnConnectionError() OVERRIDE;
+
+  // Connects client_socket_ and binds it to registrar_.
+  // Status code is passed to callback upon success or failure.
+  // May return either synchronously or asynchronously, depending on the
+  // status of the underlying socket.
+  void Connect(const net::CompletionCallback& callback);
+
+  // Registers this app with the shell at the provided URL.
+  // shell is not ready for use until register_complete_callback fires.
+  // TODO(cmasone): Once the pipe for shell can be placed in a FIFO relationship
+  // with the one underlying registrar_, the callback becomes unneeded.
+  void Register(const GURL& app_url,
+                ShellPtr* shell,
+                base::Closure register_complete_callback);
+
+ private:
+  // Handles the result of Connect(). If it was successful, promotes the socket
+  // to a MessagePipe and binds it to registrar_.
+  // Hands rv to callback regardless.
+  void OnConnect(net::CompletionCallback callback, int rv);
+
+  scoped_ptr<net::UnixDomainClientSocket> client_socket_;
+  mojo::embedder::ChannelInit channel_init_;
+  ExternalApplicationRegistrarPtr registrar_;
+};
+
+}  // namespace shell
+}  // namespace mojo
+
+#endif  // MOJO_SHELL_EXTERNAL_APPLICATION_REGISTRAR_CONNECTION_H_