[Chromoting] The desktop process now creates a pre-connected pipe and passes (with some help of the…

remoting/host/desktop_session_agent_posix.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 "remoting/host/desktop_session_agent.h"
+
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "base/eintr_wrapper.h"
+#include "base/single_thread_task_runner.h"
+#include "ipc/ipc_channel.h"
+#include "ipc/ipc_channel_proxy.h"
+#include "remoting/base/auto_thread_task_runner.h"
+
+namespace remoting {
+
+// Provides screen/audio capturing and input injection services for
+// the network process.
+class DesktopSessionAgentPosix : public DesktopSessionAgent {
+ public:
+  DesktopSessionAgentPosix(
+      scoped_refptr<AutoThreadTaskRunner> caller_task_runner,
+      scoped_refptr<AutoThreadTaskRunner> io_task_runner);
+  virtual ~DesktopSessionAgentPosix();
+
+ protected:
+  virtual bool DoCreateNetworkChannel(
+      IPC::PlatformFileForTransit* client_out,
+      scoped_ptr<IPC::ChannelProxy>* server_out) OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DesktopSessionAgentPosix);
+};
+
+DesktopSessionAgentPosix::DesktopSessionAgentPosix(
+    scoped_refptr<AutoThreadTaskRunner> caller_task_runner,
+    scoped_refptr<AutoThreadTaskRunner> io_task_runner)
+    : DesktopSessionAgent(caller_task_runner, io_task_runner) {
+}
+
+DesktopSessionAgentPosix::~DesktopSessionAgentPosix() {
+}
+
+bool DesktopSessionAgentPosix::DoCreateNetworkChannel(
+    IPC::PlatformFileForTransit* client_out,
+    scoped_ptr<IPC::ChannelProxy>* server_out) {
+  // Create a socket pair.
+  int pipe_fds[2];
+  if (socketpair(AF_UNIX, SOCK_STREAM, 0, pipe_fds) != 0) {
+    PLOG(ERROR) << "socketpair()";
+    return false;
+  }
+
+  // Set both ends to be non-blocking.
+  if (fcntl(pipe_fds[0], F_SETFL, O_NONBLOCK) == -1 ||
+      fcntl(pipe_fds[1], F_SETFL, O_NONBLOCK) == -1) {
+    PLOG(ERROR) << "fcntl(O_NONBLOCK)";
+    if (HANDLE_EINTR(close(pipe_fds[0])) < 0)
+      PLOG(ERROR) << "close()";
+    if (HANDLE_EINTR(close(pipe_fds[1])) < 0)
+      PLOG(ERROR) << "close()";
+    return false;
+  }
+
+  // Generate a unique name for the channel.
+  std::string channel_name = IPC::Channel::GenerateUniqueRandomChannelID();
+  std::string socket_name = "DesktopSessionAgent socket";
+
+  // Wrap the pipe into an IPC channel.
+  base::FileDescriptor fd(pipe_fds[0], false);
+  IPC::ChannelHandle handle(socket_name, fd);
+  server_out->reset(new IPC::ChannelProxy(
+      IPC::ChannelHandle(socket_name, fd),
+      IPC::Channel::MODE_SERVER,
+      this,
+      io_task_runner()));
+
+  *client_out = base::FileDescriptor(pipe_fds[1], false);
+  return true;
+}
+
+// static
+scoped_ptr<DesktopSessionAgent> DesktopSessionAgent::Create(
+    scoped_refptr<AutoThreadTaskRunner> caller_task_runner,
+    scoped_refptr<AutoThreadTaskRunner> io_task_runner) {
+  return scoped_ptr<DesktopSessionAgent>(new DesktopSessionAgentPosix(
+      caller_task_runner, io_task_runner));
+}
+
+}  // namespace remoting